Pre Commissioning Procedures and Formats for Switchyard Equipments

FOR INTERNAL CIRCULATION ONLY

Pre-Commissioning Procedures & Formats for Switchyard Equipments

CORPORATE OPERATION SERVICES POWER GRID CORPORATION OF INDIA LTD. GURGAON

POWER GRID CORPORATION OF INDIA LTD. CORPORATE OPERATION SERVICES

PRE-COMMISSIONING PROCEDURES AND FORMATS FOR SWITCHYARD EQUIPMENTS DOC: D-2-01-03-01-03 Revision

Department

00

CC/OS

01

Date

Signature

Signature

25.04.1995

Sd/-

Sd/-

CC/OS

05.11.1999

Sd/

Sd/

02

CC/OS

22.04.2008

Sd/

Sd/

03

CC/OS

01.04.2011

Sd/

Sd/

Proposed

Checked

Reviewed

Recommended

Sumit S.H Ray Engineer(OS)

V.K.Bhaskar Ch. Manager (OS)

S.V.P.Selvakumar AGM (OS)

P.N.Dixit GM (OS)

Anant Shukla Engineer(OS)

G Agrawal Manager(OS)

S.No.

01

Pages

All Pages

Revision

03

Approved

Sanjeev Singh ED(OS)

Remarks

All pages replaced

Doc No. D-2-01-03-01-03

CONTENTS PARTICULARS

SL.NO.

PAGE NOS

PRE-COMMISSIONING PROCEDURES FOR SWITCHYARD EQUIPMENTS

1

TRANSFORMER AND REACTOR

1

2.1

Checks after receipt of Transformer/Reactor at site

4

2.2

Insulating oil

5

2.3

Internal Inspection

6

2.4

Precautions during erection

7

2.5

Final tightness test with vacuum (i.e. leakage test or Vacuum Drop Test)

9

2.6

Oil filling

10

2.7

Hot oil Circulation using High Vacuum Filter Machine

13

2.8

Procedure for Dry Out of Wet Winding of Transformer/Reactor by Vacuum Pulling,N2 filling and Heating

14

2.9

Relation between different units (conversion of units)

16

PRE-COMMISIONING CHECKS/ TESTS FOR TRANSFORMER & REACTOR

17

3.1

Core Insulations Check

19

3.2

Earth Pit Resistance Measurement

19

3.3

Insulation Resistance (IR) Measurement

20

3.4

Capacitance & Tand Measurement of Bushing

21

3.5

Capacitance and Tand measurement of windings

24

3.6

Turns ratio (Voltage ratio) measurement

25

3.7

Vector Group & Polarity

25

3.8

Magnetic Balance test

26

3.9

Floating Neutral point measurement

27

3.10

Measurement of Short Circuit Impedance

27

3.11

Exciting/Magnetising current measurement

28

3.12

Operational checks on OLTCs

28

3.13

Tests/Checks on Bushing Current Transformer (BCT)s

29

3.14

Operational checks on Protection System

29

3.15

Stability Test of Differential, REF of Transformers/Reactor

30

3.16

Frequency Response Analysis (FRA) measurement

32

3.17

Winding resistance measurement

33

3.18

Dissolved Gas Analysis (DGA) of oil sample

34

CHECK LIST FOR ENERGISATION OF TRANSFORMER/ REACTOR

35

4.1

Preliminary checks

35

4.2

Checking of auxiliary and protective ciruits

36

v

Doc No. D-2-01-03-01-03

PARTICULARS

SL.NO

PAGE NOS

POST COMMISSIONING CHECKS/ TESTS FOR TRANSFORMERS AND REACTORS

38

5.1

Thermovision scanning (IR thermography)

38

5.2

Online Moisture Measurement

38

5.3

Vibration measurement of Oil- immersed reactor

38

PRE-COMMISSIONING CHECKS/ TESTS FOR OTHER SWITCHYARD EQUIPMENTS 6.1

39

Capacitance & Tand Measurement of CT, CVT, CB voltage grading capacitor & Surge Arresters

43

6.2

Checks/ tests applicable for Cts

43

6.3

Checks/ tests application for Circuit Breakers

47

6.4

Checks / Test applicable for CVTs

54

6.5

Checks/ tests applicable for Isolator

55

6.6

Checks/ tests applicable for Surge Arrester

55

6.7

Checks/ tests applicable for other areas/equipments

56

BUS BAR PROTECTION

59

7.1

High Impedance Protection

59

7.2

Low Impedance Protection

60

7.3

Primary injection and bus bar differential stability test (New Substation)

61

7.4

Primary injection and bus bar differential stability test (Bay Extension in the old substation)

62

7.5

Scheme Checking of bus bar protection & DC trip logic. (New substation & Bay extension)

64

7.6

AMP Testing of bus bar protection and scheme

65

7.7

Double main transfer scheme (400kV/220kV)

66

7.8

Scheme checking of bus bar protection & DC trip logic. (New substation & Bay extension)

73

7.9

AMP testing of bus bar protection and scheme

74

PRE-COMMISSIONING FORMATS FOR SWITCHYARD EQUIPMENT 1

No. CF/ICT/01/ R-3 DATED 01/04/2011 ICT

2

No. CF/SR/02/ R-3 DATED 01/04/2011SHUNT REACTOR

101

3

No. CF/CB/03/ R-3 DATED 01/04/2011 CIRCUIT BREAKER

117

4

No. CF/CT/04/R-3 DATED 01/04/2011 CURRENT TRANSFORMER

130

5

No. CF/CVT/05/R-3 DATED 01/04/2011 CVT

140

6

No. CF/BAY/06/R-3 DATED 01/04/2011 BAY/FEEDER

145

7

No. CF/ISO/07/ R-3 DATED 01/04/2011 ISOLATOR/GROUND SWITCH

154

8

No. CF/SA/08/ R-3 DATED 01/04/2011 SURGE ARRESTER

159

9

No. CF/WT/09/ R-3 DATED 01/04/2011WAVE TRAP

162

10

No. CF/C&P/10/R-3 DATED 01/04/2011 CONTROL & PROTECTION

164

vi

75

Doc No. D-2-01-03-01-03

PRE-COMMISSIONING PROCEDURES FOR SWITCHYARD EQUIPMENTS

1.1

Purpose This document is to provide guidance to POWERGRID personnel in carrying out Precommissioning checks along with formats for recording the test data and subsequently charging of Substation Bay equipments along with associated auxiliary equipments. Pre-commissioning checks/ tests are the activities carried out to ascertain the correctness, completeness of installation and healthiness of the equipment before its charging. These checks/ tests are to be carried out by Contractor's representative in the presence of POWERGRID's authorized representative.

1.2

Commissioning Team

1.2.1

Constitution of Commissioning team: After completion of erection in all respects, a commissioning team may be constituted (as per procedures laid down in Works & Procurement Policy and Procedures -Clause C2.15.4.6 of WPPP Vol. II), to oversee/ coordinate with erection agency/ manufacturer of the equipment for the pre-commissioning tests and subsequently charging of the equipment. In case of Substation, Commissioning team may consist of following:

1.2.2

(I)

I/C of Substation

(ii)

O&M executive not below Manager

(iii)

T&C executive not below Sr. Engineer

Role of Commissioning team: The Commissioning Team shall examine the following statutory and other clearances obtained by Execution Site prior to clearance for test charging of the equipment/transmission line at rated voltage: Statutory Clearances: a)

Electrical Inspector's Clearance (provisional or final) for charging transmission line/bay equipment as per I.E. rules.

b)

P.T.C.C. clearance.

c)

Copy of notification informing public/administration regarding charging of the line. d) Forest Clearance Other Clearances:

a)

Charging instruction from SEF Group of Corporate Engineering.

Pre-Commissioning Procedures For Switchyard Equipments

1

Doc No. D-2-01-03-01-03

b)

Relay setting details from Corporate Engineering.

(Clause C2.15.4.8 (v) of WPPP Vol-II) 1.2.3

Responsibilities of Commissioning team The responsibilities of the commissioning team are to go through statutory clearances and standing instructions before initial charging of new equipment, witness Pre-Commissioning tests after erection of individual equipment as per requirement of guidelines issued by Corporate OS or in line with manufacturer's recommendation and test charging, investigate failure of equipment during test charging, declare commencement of trial operation and evaluate guaranteed test results and recommend acceptance as may be provided in the contract, list out deviations/ exception/ incomplete work, for acceptance/ rejection (Clause C2.15.4.7 of WPPP Vol-II). Proper documentation also to be ensured by the Commissioning team based upon the observations for the above for future reference. 1.2.4 The Team shall also go through the factory test reports. If such tests have been repeated during pre-commissioning, the Team shall list out deviations, if any, in the results of precommissioning tests with respect to the factory tests. (Clause C2.15.4.8 (vii) of WPPP Vol-II) 1.2.5 After all pre-commissioning checks and tests are found to be acceptable taking into account permissible deviation limits, the commissioning team, in consultation with regional O&M, shall give clearance for commissioning/ charging. Please Note: In case of Transformers & Reactors, commissioning team shall forward the PreCommissioning report along with their recommendations to RHQ-OS and CC-OS for charging clearance and CC-OS shall give the final charging clearance after reviewing of the test results. 1.3

Safety All measures and precautions should be undertaken to prevent occurrence of unsafe acts. All the personnel involved should be thoroughly apprised about the safe procedures to be adopted while performing various activities including carrying out tests in the switchyard. Adequate fire-fighting system as per procedures and their healthiness is to be ensured before charging. Warning signs and Safety barriers should be positioned in conformity to IE rules as amended from time to time.

1.4

General Procedures during Pre-commissioning of Switchyard Equipment All the equipment after erection/assembly at site, should be tested in order to check that it has not been damaged during transport, erection/assembly to such an extent that its future operation will be at risk. The significance of various tests with brief procedure has been elaborated in the subsequent sections of this document. Regarding the detailed testing methods / procedures for conducting various pre-commissioning tests refer to Doc. No. D-203-XX-01-01: Maintenance Procedures for Switchyard Equipments-Part 1: EHV Transformers & Reactors and Doc No. D-2-03-XX-01-01 –Part 2: Other Switchyard Equipments.

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1.5

Documentation The results of the test shall be documented on the test record formats as mentioned below, which are also part of this documentation: Sl. No. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10.

FORMAT NO. No. CF/ICT/01/ R-3 DATED 01/04/2011 No. CF/SR/02/ R-3 DATED 01/04/2011 No. CF/CB/03/ R-3 DATED 01/04/2011 No. CF/CT/04/R-3 DATED 01/ 04/2011 No. CF/CVT/05/R-3 DATED 01/04/2011 No. CF/BAY/06/R-3 DATED 01/04/2011 No. CF/ISO/07/ R-3 DATED 01/ 04/2011 No. CF/SA/08/ R-3 DATED 01/04/2011 No. CF/WT/09/ R-3 DATED 01/04/2011 No. CF/C&P/10/R-3 DATED 01/ 04/2011

EQUIPMENT ICT SHUNT REACTOR CIRCUIT BREAKER CURRENT TRANSFORMER CVT BAY/FEEDER ISOLATOR/GROUND SWITCH SURGE ARRESTER WAVE TRAP CONTROL & PROTECTION

These formats have all the tests recordings to be performed at site before energization/ charging. Switching and operational activities will be recorded in regular manner in the operator's log. Copies of this log, notes on special observations from inspections and other measurements will constitute the test records. The test records had to be signed by the responsible personnel from the OEM, the supplier, the erection agency and the POWERGRID representative. The test formats/records are to be distributed to Regional O&M office and Concerned Sub-Station library.


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Doc No. D-2-01-03-01-03

TRANSFORMER AND REACTOR 2.1

Following points to be checked after receipt of transformer / reactor at Site:

2.1.1

N2 pressure and Dew point to be checked after receipt of transformer at Site. It should be within permissible band (as per graph provided by manufacturer & given below in Fig-1)

2.1.2

Core Insulation Test shall be carried out to check insulation between Core (CC&CL) and Ground. (Not applicable for Air Core Reactors)

2.1.3

The data of impact recorder shall be analyzed jointly in association with the manufacturer. In case the impact recorder indicates shocks of ≥3g during shipment, further course of action for internal inspection shall be taken jointly with the manufacturer/ supplier. Impact Recorder should be detached from the Transformer/ Reactor preferably when the main unit has been placed on its foundation. As present day impact recorders are of electronic type, analysis of impact recorder along with dew point and Core insulation tests to be performed on trailer itself. In case, the test results are not meeting permissible limits, same to be informed to OEM, CC-Engg. & CC-OS for further course of action. Graph showing variation of Pressure v/s Temperature of gas for gas filled unit during Transport or storage Lb / in 5

Gauge Pressure – Kg/ Cm2

4.5

2

0.35

Permissible Range

A2

0.3

4.0 3.5 3.0

0.25

A1

0.2

2.5 2.0

0.15

1.5 1.0

0.1 0.05

0.5 0.05 0

-0.05 0.05

-30

-20

-10

0

10

20

30

40

50

Temperature in ° C Example: For 40 °C Temperature (Depending upon the pressure of gas at the time of filling), - minimum pressure of gas can be 0.185 Kg/ Cm 2 at point A1 - maximum pressure of gas can be 0.32 Kg/ Cm 2 at point A2

Fig. 1 4


Doc No. D-2-01-03-01-03

2.1.4

Unpacking and inspection of all accessories to be carried out taking all precautions so that the tools used for opening do not cause damage to the contents. Proper storage of all accessories are to be ensured after unpacking. Fragile instruments like oil level gauge, temperature indicators, etc. are to be stored indoor. Any damaged or missing components should be reported to equipment manufacturer and insuring agency so that the same can be investigated or shortage made up as per the terms/ conditions of the contract.

2.1.5

Storage of the main unit and the accessories at site: Ø If erection work can not start immediately due to some reasons, then accessories should be repacked into their own crates properly and packing list should be retained. Ø All packing cases should be kept above ground by suitable supports so as to allow free air flow underneath. The storage space area should be such that it is accessible for inspection, water does not collect on or around the area and handling/transport would be easy. Proper drainage arrangement in storage areas to be ensured so that in no situation, any component gets submerged in water due to rain, flooding etc. Ø It is preferable to store the main unit on its own location/foundation. If the foundation is not likely to be ready for more than three (3) months, then suitable action plan has to be taken from the manufacturer regarding proper storage of the Main Unit. Ø If the transformer/ Reactor is to be stored up to three (3) months after arrival at site, it can be stored with N2 filled condition. N2 pressure to be monitored on daily basis so that chances of exposure of active part to atmosphere are avoided. In case of drop in N2 pressure, dew point of N2 has to be measured to check the dryness of the Transformer/ Reactor. If there is drop in dew point, fresh nitrogen need to be filled. Leaks are to be identified and rectified and Nitrogen to be filled to the required pressure. Ø In case the transformer/ reactor is to be stored for more than 3 months, it needs to be stored in oil filled condition. Processed oil to be filled which complies the required specification and ppm ≤5ppm and BDV ≥70kV. In case of storage of transformer in oil-filled condition, the oil filled in the unit should be tested for BDV and moisture contents once in every three months. The oil sample should be taken from bottom valve. If BDV is less and moisture content is more than as given for service condition then oil should be filtered.

2.2

Insulating Oil When oil is dispatched to site separately it is usually in sealed steel drums. In some of the cases, oil is supplied in tankers also. The oil to be used to filling and topping up must comply with oil specification given in POWERGRID Technical Specification for acceptance criteria. Oil Samples shall be taken from oil drums/ tanker received at site and sent to our nearest oil Lab for oil parameter testing (BDV > 50 kV, ppm<40, Resistivity > 150 x 1012 Ohm-cm & Tan delta < 0.0025 @ 90 °C). The latter is important since dirty transportation vessels can significantly contaminate the oil. High dielectric losses cannot be removed by filter treatment, such lots have to be rejected. If the oil is supplied in railroad or trailer tanks, one or two samples are sufficient. If the oil is delivered in 200 litres drums, the following scheme for checking is recommended.


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Number of drums delivered 2 to 5 6 to 20 21 to 50 51 to 10 101 to 200 201 to 400

No. of drums to be checked 2 3 4 7 10 15

In case any doubt arises, number of drums to be checked needs to be increased. However, before filling oil, each drum has to be physically checked for free moisture and appearance. A register needs to be maintained indicating the number of drums supplied in each lot as per LOA and number of drums of each lot used in filling a particular Transformer/ Reactor. The oil test results carried out as above should also be recorded. The copy of test certificate of routine testing at oil refinery should be available at site for comparison of test results. 2.2.1

Samples from Oil Drum Check the seals on the drums. The drum should first be allowed to stand with bung (lid) vertically upwards for at least 24 hours. The area around the bung should be cleaned & clean glass or brass tube long enough to reach to within 10mm of the lowermost part of the drum should be inserted, keeping the uppermost end of the tube sealed with the thumb while doing so. Remove the Thumb thereby allowing oil to enter the bottom of the tube. Reseal the tube and withdraw an oil sample. The first two samples should be discarded. Thereafter, the sample should be released into a suitable receptacle. Samples to be collected preferably in clean glass bottles. The bottles are to be rinsed with the same oil and to be without any air bubble.

2.3

Internal Inspection Before starting erection, thorough internal inspection of Transformer/ Reactor is to be carried out by POWERGRID engineer along with manufacturer's representative. Internal inspection should be preferred in dry and sunny weather and should be finished as quickly as possible to avoid ingress of moisture admitting dry air. Prior to making any entry into the transformer tank, establish a foreign material exclusion programme to avoid the danger of any foreign objects falling into the transformer: Ø Loose articles should be removed from the pockets of anyone working on the transformer cover. Ø All jewellery, watches, pens, coins and knives should be removed from pockets. Ø Protective clothing and clean shoe covers are recommended. Ø Tools should be tied with clean cotton tape or cord securely fastened. Ø Plated tools or tools with parts that may become detached should be avoided. Ø An inventory of all parts taken into transformer should be recorded and checked before closing inspection cover to assure all items were removed.

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If any object is dropped into the transformer and cannot be retrieved, the manufacturer should be notified. The inspection should include: Ø Removal of any shipping blocking or temporary support. Ø Examination for indication of core shifting. Ø Tests for unintentional core or core clamp grounds. Ø Visual inspection of windings, leads, and connections including clamping, bracing, blocking, spacer alignment, phase barriers, oil boxes, and coil wraps. Ø Inspection of DETC and in-tank LTCs including contact alignment and pressure. Ø Inspection of current transformers, including supports and wiring harness. Ø Checks for dirt, metal particles, moisture, or other foreign material. In case of any abnormality noticed during internal inspection, same to be referred to manufacturer, CC-Engg. & CC-OS immediately before starting erection activities. Detailed photographs of all visible parts/ components as per above are to be taken during internal inspection and to be attached with pre-commissioning report. 2.4

Precautions during erection During erection, efforts to be made to minimize the exposure of active parts (core and coils) of transformer/ reactor. Moisture may condense on any surface cooler than the surrounding air. Excessive moisture in insulation or dielectric liquid lowers its dielectric strength and may cause a failure of Transformer/ Reactor. Further, either dry air generator should be running all the time or dry air cylinders may be used to minimize ingress of moisture. The transformer should be sealed off after working hours. Transformer/ reactor shall never be allowed to be opened without application of dry air. Remarks: As N2 is heavier than air, application of Vacuum to be ensured and thereafter dry air to be admitted before entering inside Transformer after shipment in N2 filled condition. Oxygen content should be between 19 % and 25 % prior to any entry. During inspection, dry air to be purged continuously. It is practical to apply a slight overpressure overnight with dry air or N2 inside – less than 300 mbar (30 kPa or 0.3 atmospheres). Next day the pressure is checked and suspected leaks may be detected with leak detection instruments/ with soap water or with plastic bags tightened around valves (being inflated by leaking air) For oil filled units whenever oil is drained out below the inspection covers, job will be treated as exposed. Other exposure activities are as below: 1) 2) 3) 4) 5) 6) 7)

Bushing erections Jumper connections of Bushings Fixing bushing turrets Core insulation checking (in case the checking point not accessible outside) Buchholz relay pipe work fixing on cover Gas release pipes/equalizer pipe fixing Entering inside the tank for connections/inspection etc


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For oil filled units depending upon the level up to which the oil is drained decides the exposure time. All such exposure time should be recorded in a log sheet to decide the oil processing (drying) and oil filling of transformer. "GET THE TRANSFORMER UNDER OIL AS SOON AS POSSIBLE!" It is good practice to proceed with the erection in such a sequence that all fittings and auxiliaries with oil seals to the tank are assembled first. The oil filling will then be performed as easily as possible. The "active part" inside - core and coils - is then impregnated and protected. It has good time to soak properly, before the unit shall be energized, while remaining fittings are assembled on the unit, and commissioning checks carried out.

For transformers with a gas pressure of 2.5- 3 PSI, the acceptable limits of dew point shall be as under: (Courtesy: BHEL, Bhopal)

Temperature of Insulation in°F 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 110 120 130 140

Permissible dew point in °F -78 -74 -70 -66 -62 -58 -53 -48 -44 -40 -35 -31 -27 -22 -18 -14 -10 -6 -1 +3 +7 +16 +25 +33 +44

Temperature of Insulation in°C -17.77 -15.0 -12.22 -9.44 -6.66 -3.33 -1.11 +1.66 +4.44 +7.44 +9.99 12.77 15.55 18.33 23.11 23.88 26.66 29.44 32.22 34.99 37.75 43.33 48.88 54.44 59.99

Permissible dew point in °C -61.11 -58.88 -56.66 -54.44 -52.22 -49.99 -47.22 -44.44 -42.22 -39.39 -37.22 -34.99 -32.77 -29.99 -27.77 -25.55 -23.33 -21.11 -18.33 -16.11 -13.88 -8.88 -3.88 +0.55 +5.55

TABLE 1- Variation of Dew Point of N2 Gas Filled in Transformer Tank w.r.t Temperature 8


Doc No. D-2-01-03-01-03

2.5

Final tightness test with vacuum (i.e. leakage test or Vacuum Drop Test) Before oil filling is started, a final check is made for the tightness of the transformer tank by applying vacuum. When vacuum is applied to a transformer without oil, a leakage test must be carried out to ensure that there are no leaks in the tank which would result in wet air being drawn into the transformer. The following procedure is to be adopted: Ø Connect the vacuum gauge to a suitable valve of the tank. (Vacuum application and measurement should be performed only on top of the main tank) - A vacuum gauge of Mc Leod type or electronic type, with a reading range covering the interval - 1 kPa (1 - 10 mm mercury) to be used Ø Connect the vacuum pump to another opening. Ø Evacuate the transformer/ reactor tank until the pressure is below 3 mbar ( 0.3 kPa or about 2 mm of Hg) Ø Shut the vacuum valve and stop the pump. Ø Wait for an hour and take a first vacuum reading – say P1 Ø Take a second reading 30 minutes later- say P2 Ø Note the volume of the tank (quantity of oil required according to the rating plate) and express as volume, V, in m3 Ø Take the difference between P2 and P1, and multiply this with the oil quantity V. If the pressures are expressed in kPa, and the oil quantity in m3, then the product shall be less than 3.6. (P2 – P1) x V < 3.6 The transformer is then considered to be holding sufficient vacuum and is tight. Continue reading (at least 2 to 3) at successive 30 min intervals to confirm the result. Ø If the leak test is successful, the pumping will be continued, until the pressure has come down to 0.13 kPa (1 Torr) or less. The vacuum shall then be held for the time given in Table-3 before the oil filling starts. Ø If the specified vacuum cannot be reached, or if it does not hold, the leak in the transformer system shall be located and corrected. In case the transformer is provided with an On Load Tap Changer (OLTC), while evacuating the main transformer tank, the diverter switch compartment may also be evacuated simultaneously so that no undue pressure is allowed on the tap changer chamber. While releasing vacuum, the tap changer chamber vacuum should also be released simultaneously. For this one pressure equalizer pipe should be connected between main tank and tap changer. Manufacturer's instruction manual should be referred to protect the air cell/diaphragm in the conservator during evacuation. This vacuum must be maintained for the time specified as per the voltage class in Table-3 before and should also be maintained during the subsequent oil filling operations by continuous running of the vacuum pumps.


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Doc No. D-2-01-03-01-03

2.6

Oil Filling Once the oil is tested from the drums and found meeting the requirements, the oil is transferred to oil storage tank for oil filtration before filling inside the transformer. The drums or trailer tanks shall not be emptied to the last drop - a sump of an inch or so is left, to avoid possible solid dirt or water in the bottom. Before being used, the tanks and hoses are visually inspected inside for cleanness. Any liquid residue from earlier use will be carefully removed, and the container flushed with a small quantity of new oil, which is then discarded. After filtration, oil sample is tested for meeting POWERGRID specification for new oil. Prior to filling in main tank at site and shall be tested for: 1. Break Down voltage (BDV) 2. Moisture content 3. Tan-delta at 90 °C 4. Interfacial tension

: : : :

70kV (min.) 5 ppm (max.) Less than 0.01 More than 0.035 N/m

For transformer dispatched with gas (N2) filled from the works, the filling of oil inside the tank is done under vacuum. Transformer of high voltage ratings and their tanks are designed to withstand full vacuum. Manufacturer's instructions should be followed regarding application of full vacuum during filling the oil in the tank. When filling a transformer with oil it is preferable that the oil be pumped into the bottom of the tank through a filter press or other reliable oil drying and cleaning device should be interposed between the pump and the tank (please refer Fig-2). The oil flow at the entry valve must be controlled to maintain a positive pressure above atmospheric and to limit the flow rate if necessary to 5000 litres / hour, or a rise in oil level in the tank not exceeding one meter / hour (as measured on the oil level indicator) Continue oil filling until the level reaches approximately 200 mm above the ambient oil level indicated on the magnetic oil level gauge in the expansion vessel. Then, release the vacuum, with dry air of dew point -40deg C or better. The diverter tank can now be topped up at atmospheric pressure. Reconnect oil outlet hose to valve on flange on tap changer diverter head. Reinstate breather and very slowly top up the diverter switch such that the correct level is reached in the diverter expansion vessel. In the event the expansion vessel is overfull drain oil from flange into a suitable container until the correct level is reached.

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Valve near B. RELAY towards Conservator

Compound Pressure & Vacuum gauge Filter on any 1” Sampling or 2” Filter Valve

B.R.

A

C

B VACUUM PUMP

SUMP

Tank Oil Gauge/ Transparent hose for Level monitoring TRANSFORMER TANK

OIL STORAGE TANK

Top Filter Valve

FILTER MACHINE

D.O.F. Filter Valve If not, then BTM Filter Valve

Figure-2 : Arrangement for Evacuation and Oil filling upto tank Oil gauge & Conservator When the vacuum filling of the transformer and diverter tank is complete, the cooling system/ Radiator bank can be filled (WITHOUT VACUUM) at atmospheric pressure, via an oil processing plant. Oil must be admitted, very slowly, through the bottom cooler filter valve, with the cooler vented at the top and the top cooler filter valve unblanked and open to atmosphere. As the oil level reaches the top vent, then top valve to be closed and the processing plant can be shut down. Note: Care must be taken not to pressurize the coolers/ radiators. Upon completion, open the top cooler isolating valve in order to equalize the pressure in the cooler with the transformer tank. This will also allow contraction or expansion of the oil as the ambient temperature changes. Before filling oil into the conservator, the air cell/ bellow to be inflated to 0.5 PSIG i.e. 0.035kg/cm2 max. by applying pressure (N2/Compressed dry air) so that it can take shape. After releasing pressure, breather pipe is to be fitted however it is recommended not to fit breather in position, instead a wire mesh guard over and flange of the pipe to prevent entry of any insect inside the pipe. This will ensure free air movement from the air cell to the atmosphere. Use flow meter / indicator on outlet of filter machine and regulate the flow using the valve to limit oil filling rate to 2000 litres per hour (max.) in case filter capacity is more.


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Oil to be pushed slowly into conservator through the transformer via valve No. 5 (valve 2,3 & 4 to remain open) till the oil comes out first through valve Nos.2 & 3 (close these valves) and then through valve No. 4. Allow some oil to come out through valve No.4. Oil should come out freely into the atmosphere. This will ensure that air inside the conservator is expelled out and the space surrounding the air cell is full of oil. (Close valve No. 4). During all these operations valve No.1 shall be in closed position. Excess oil from the conservator is to be drained by gravity only through valve No. 1 or through drain valve of the transformer via valve No. 5. Do not use filter machine for draining oil from the conservator. Also do not remove buchholz relay and its associated pipe work, fitted between the conservator and the transformer tank while draining oil. Stop draining oil till indicator of magnetic oil level gauge reaches position-2 on the dial, which is corresponding to 30C reading on the oil temperature indicator. Fill the conservator according to the oil temperature and not the atmospheric temperature

Figure-3 : General Arrangement For Oil Conservator After Oil filling, Hot Oil Circulation has to be applied to all the Transformers/ Reactors except under the circumstances when active part of Transformer/ Reactor gets wet. Following conditions can be considered to define the Transformer/ Reactor wet: 1.

If Transformer/ Reactor received at site without positive N2 pressure.

2.

If Dry air not used during exposure while doing erection activities

3.

Overexposure of active part of Transformer/ Reactor during erection (Overexposure when exposure > 12 Hrs)

Under above mentioned conditions, Manufacturer shall take necessary action for effective dry out of the Transformer/ Reactor. However general guidelines for dry out in such cases is given in section 2.8

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2.7

HOT OIL CIRCULATION USING HIGH VACUUM OIL FILTER MACHINE To ensure proper dryness and absorption of possible trapped gas bubbles, the oil in the tank is circulated through the vacuum filter and with circulation direction as shown in Fig.-4. The circulation procedure for the main tank is as follows.

2.7.1

The Transformer/ Reactor is connected to the oil filter machine in a loop through the upper and lower filter valves. The direction of circulation shall be from the filter to the transformer at the top and from the transformer to the filter at the bottom. (Please note that at the initial oil filling time the direction is reverse to avoid air bubble formation).

2.7.2

The temperature of the oil from the filter to the Transformer should be around 60 ° C and in no case it should go beyond 70 ° C otherwise this may cause oxidation of oil.

2.7.3

The circulation shall proceed until a volume of oil has passed through the loop corresponding to 2 times the total oil volume in the tank. (At freezing ambient temperature the circulation time is increased, circulate 3 times the volume at temperature down to minus 20 ° C, increase to 4 times below that temperature). The oil sample from the transformer tank, after filling in tank before commissioning should meet the following specifications (as per latest POWERGRID Revision) given in table-2 below. 1. 2. 3. 4. 5. 6. 7.

8.

Break Down voltage (BDV) : 70 kV (min.) Moisture content : 5 ppm (max.) Tan-delta at 90 °C : 0.01 (max.) Total Gas Content : < 1% Resistivity at 90 °C : 6 X 1012 ohm-cm (min.) Interfacial tension : 0.035 N/m (min.) *Oxidation Stability (Test method as per IEC 61125 method C, Test duration: 500 hour for inhibited oil) a) Acidity : 0.3 (mg KOH /g) (max.) b) Sludge : 0.05 % (max.) c) Tan delta at 90 °C : 0.05 (max.) * Total PCB content : Not detectable (2 mg/kg total)

* For Sr. No. 7 & 8 separate oil sample shall be taken and test results shall be submitted within 45 days after commissioning for approval of Powergrid. Table-2


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Figure-4: Arrangement for Hot Oil Circulation and Filtration 2.8

PROCEDURE FOR DRY OUT OF WET WINDING OF TRANSFORMER/ REACTOR BY APPLICATION OF VACUUM, N2 FILLING AND HEATING The drying of a new Transformer/ Reactor is required when the moisture gets absorbed by the solid insulation used in Transformers/ Reactors due to various reasons. The process of drying out a transformer requires care and good judgment. If the drying out process is carelessly or improperly performed, a great damage may result to the transformer insulation. In no case shall a transformer be left unattended during any part of the dry out period unless on-line dryout process is adopted which incorporates all necessary safety features. The transformer should be carefully watched throughout the dry-out process and all observations to be carefully recorded. When the transformer is being dried out, it is necessary to ensure that fire fighting equipment is available near the transformer as a precaution as there are chances of fire as we are dealing with heat and inflammable oil.

2.8.1

Isolation Required All the openings of transformer main tank like openings for coolers/radiators, conservator, OLTC etc. is to be properly isolated and totally blanked.

2.8.2 Procedure a. Fill the main transformer/ reactor tank with Nitrogen (Use only Dry N2 gas as per IS: 1747 with less than 50 ppm moisture and 1% oxygen by volume) until it comes to a positive pressure of 0.15 Kg/cm2. It is kept for about 48 hrs. At the end of 48 hrs, dew point of N2 at outlet is measured. If the dew point is not within acceptable limits as per Table-I, dry out method should be continued. 14


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b.

While N2 circulation is in progress, the heaters are to be installed around the transformer tank. The heaters are to be kept ON until we achieve a temperature of about 75–80 deg C of the core & winding of transformer as measured by top oil temperature in the transformer.

c.

After ascertaining that there is no leakage, pull out vacuum and keep the transformer/reactor under near absolute vacuum (1-5 torr) and keep under vacuum for about 96 hours running the vacuum pump continuously. The duration of vacuum can vary between 48 to 96 hrs depending upon the dew point being achieved. Keep vacuum machine ON and collect condensate for measurement. Observe the rate of condensate collection on hourly basis. Depending on the value of rate of condensate (less than 40 ml/hr for 24 hrs), continuation of further vacuum shall be decided.

d.

Then the vacuum is broken with dry nitrogen. The dew point of nitrogen at the inlet is to be measured and should be of the order of - 500 C or better. When the nitrogen comes to the positive pressure of 0.15 kg/cm2, it is stopped and kept for 24 hours. Heating from outside is to be continued while N2 circulation is in progress. Then the nitrogen pressure is released and the outlet nitrogen dew point is measured. If the dew point is within acceptable limits as per Table-I then the dryness of transformer is achieved. If not again the transformer is taken for vacuum treatment and then nitrogen is admitted as mentioned above and tested. The cycle is to be continued till desired dew point as per Table-1 is achieved.

e.

Periodicity of vacuum cycle may vary between 48-96 hrs. Initially two N2 cycles may be kept for 24 hrs. After that it may be kept for 48 hrs depending upon dew point being achieved.

After completion of drying process, oil filling and hot oil circulation is to be carried out before commissioning. Please ensure standing time as per table-3 given below before charging. Note: If already known that the transformer is wet based on the tests or exposure time, then (a) above can be skipped to save time. Transformer HV Application of Vacuum & STANDING TIME After Oil Rated Voltage holding for (before oil filling)* circulation and before energising (in kV) (in Hours) (in Hours) Up to 145kV 12 HRS 12 HRS 145 kV and up to 24 HRS 48 HRS 420kV Above 420 kV 36 HRS 120 HRS *Without running the vacuum pump and leakage rate to be ≤40mbar-lit/sec Table-3

After the expiry of this time, air release operation is to be carried out in Buchholz relays, turrets and other release points given by the manufacturers before charging. For subsequent activities, proceed to format no. CF/ICT/01/ R-3 Dated 01/01/2011 for ICT & format No. CF/SR/02/ R-3 Dated 01/01/2011 for Reactor. Refer pre-commissioning test procedures given in next section for all required tests to be performed.


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2.9

RELATION BETWEEN DIFFERENT UNITS (CONVERSION OF UNITS):

Pressure 1 bar = 105 Pa = 750 Torr = 14.5 psi = 1.02kg/cm 2 1 Torr = 1.33 mbar = 0.133 kPa 1 kPa(kilo-Pascal) = 103 Pa = 10 mbar = 7.501 Torr(mm of mercury) 1 MPa = 106 Pa 1 atmosphere=0.1 MPa=1.02kg/cm2= 14.5 psi Force 1 kp = 9.807 N Weight 1 ton=1000 kg=2200 lbs Temperature °C= °F=

5 * (° F - 32) 9 9 * (° C )+ 32 5

Volume 1m3= 1000 litres=260 US gallons=220 Imp gallons 1 litre =0.26 US Gallons 1 US Gallons = 3.78 litres 1 litre =0.22 Imp Gallons 1 Imp Gallons Benchmarks 1-mm mercury (Torr) is about 1 millibar or 0.1 kPa 1 m3 of oil weights 0.9 tons –say 1 ton 1000 US gallons of oil weights 3.5 tons

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PRE- COMMISSIONING CHECKS/TESTS FOR TRANSFORMERS AND REACTORS Once oil filling is completed, various pre-commissioning checks/ tests are performed to ensure the healthiness of the Transformer/ Reactor prior to its energization. Various electrical tests are to be performed and their significance is given below Sr. No.

Name of Test/ Check point

Purpose of test/ check

3.1

Core insulation tests

Allows for investigating accidental grounds which results in circulating currents if there is more than one connection between the core and ground.

3.2

Earth pit resistance To check the resistance of earth pit provided for Transformer. In measurement case, the resistance is more, proper treatment is to be given.

3.3

Insulation Resistance (IR) measurement

Test reveals the condition of insulation (i.e. degree of dryness of paper insulation), presence of any foreign contaminants in oil and also any gross defect inside the transformer (e.g. Failure to remove the temporary transportation bracket on the live portion of tap-changer part)

3.4

Capacitance and Tanä measurement of bushings

Measurement of C1 & C2 Capacitance and Tanä in UST mode. Changes in the normal capacitance of an insulator indicate abnormal conditions such as the presence of moisture layer, short -circuits or open circuits in the capacitance network.

3.5

Capacitance and Tan ä measurement of windings

Dissipation factor/Loss factor na d capacitance measurement of winding is carried out to ascertain the general condition of the ground and inter-winding insulation

3.6

Turns ratio (Voltage ratio) measurement

To determine the turns ratio of transformers to identify any abnormality in tap changers/ shorted or open turns etc

3.7

Vector Group & Polarity

To determine the phase relationship and polarity of transformers

3.8

Magnetic Balance test

This test is conducted only in three phase transformers to check the imbalance in the magnetic circuit

3.9

Floating Neutral point measurement

This test is conducted to ascertain possibility of short circuit in a winding.

3.10 Measurement of Short Circuit Impedance

This test is used to detect winding movement that usually occurs due to heavy fault current or mechanical damage during transportation or installation since dispatch from the factory.


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3.11 Exciting/Magnetising To locate defect in magnetic core structure, shifting of windings, current measurement failures in turn to turn insulation or problems in tap changers. These conditions change the effective reluctance of the magnetic circuit thus affecting the current required to establish flux in the core 3.12 Operational checks on OLTCs

To ensure smooth & trouble free operation of OLTC during operation.

3.13 Tests/ Checks on Bushing Current Transformers (BCTs)

To ascertain the healthiness of bushing current transformer at the time of erection

3.14 Operational Checks on protection System

Operational checks on cooler bank (pumps & Fans), Breathers (Silicagel or Drycol), MOG, temperature gauges (WTI/OTI), gas actuated relays (Buchholz, PRD, SPR etc.) and simulation test of protection system

3.15 Stability of This test is performed to check the proper operation of Differential, REF of Differential & REF protection of Transformer & Reactor by Transformer/ Reactor simulating actual conditions. Any problem in CT connection, wrong cabling, relay setting can be detected by this test. 3.16 Frequency Response Analysis (FRA) measurement

To assess the mechanical integrity of the transformer. Transformers while experiencing severity of short circuit current looses its mechanical property by way of deformation of the winding or core. During pre-commissioning this test is required to ascertain that Transformer active part has not suffered any severe impact/ jerk during transportation.

3.17 Winding resistance measurement

To check for any abnormalities due to loose connections, broken strands and high contact resistance in tap changers

3.18 Dissolved Gas Analysis (DGA) of oil sample

Oil sample for DGA to be drawn from transformer main tank before commissioning for having a base data and after 24 hrs. of charging subsequently to ensure no fault gas developed after first charging. DGA analysis helps the user to identify the reason for gas formation & materials involved and indicate urgency of corrective action to be taken

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3.1

CORE INSULATION TEST

This test is recommended first after receiving the equipment at site and to be performed on trailer itself. Thereafter, before the unit is placed in service or following modifications to the transformer that could affect the integrity of its core insulation and at other times, when indicated by DGA (key gases being ethane and/or ethylene and possibly methane) or usually during a major inspection. For core-insulation to ground test, remove the cover of the terminal block, Disconnect the closing link that connects the two terminals CL-G. Apply 1.0 kV direct voltage between CL and CC + G (core grounding strap). The tank shall be grounded during the test. Acceptable Limit: The insulation value after 1min. should be minimum 10 M for new transformer at the time of commissioning. Core insulation resistance is generally more than 100 M for new assembled transformer when tested at factory. 3.2

Earth pit resistance measurement Earth tester is used for measurement of Earth resistance. If earth resistance is more, proper treatment is to be given. For measurement of earth pit resistance, pit earthing connection should be disconnected from main grid. Thereafter, measurement is to be carried out by three point method. Working of Earth Tester: - There is hand operated D.C.generator. While feeding current to spike, D.C. current is converted into A.C. current by the converter and A.C. current received from spike is again converted in D.C. current by the help of rectifier, while going to generator. A.C. current is fed to the spike driven in earth because there should not be electrolytic effect. Measurement of Earth Resistance (Three point method):-

Figure-5 Pre-Commissioning Procedures For Switchyard Equipments

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In this method, earth tester terminals C1 & P1 are shorted to each other and connected to the earth electrode (pipe) under test. Terminals P2 & C2 are connected to the two separate spikes driven in earth. These two spikes are kept in same line at the distance of 25 meters and 50 meters due to which there will not be mutual interference in the field of individual spikes. If we rotate generator handle with specific speed we get directly earth resistance on scale. Acceptable Limit: Value of earth pit resistance should be less than or equal to 1? . 3.3

INSULATION RESISTANCE (IR) MEASUREMENT

IR measurements shall be taken between the windings collectively (i.e. with all the windings being connected together) and the earthed tank (earth) and between each winding and the tank, the rest of the windings being earthed. Before taking measurements the neutral should be disconnected from earth. Following table gives combinations of IR measurements for auto-transformer, three -winding transformer & Shunt Reactor

For Auto-transformer HV + IV to LV HV + IV to E LV to E

For 3 winding transformer HV + IV to LV HV + LV to IV HV + IV +LV to E

For Shunt Reactor HV to E

Where HV-High voltage, IV-Intermediate voltage, LV-Low voltage/Tertiary voltage windings, E- Earth

Acceptable Limits: Unless otherwise recommended by the manufacturer, the following IR values as a thumb rule may be considered as the minimum satisfactory values at 30°C (one minute measurements) at the time of commissioning. Rated Voltage class of winding 11kV 33kV 66kV & above

Minimum desired IR value at 1 minute (Meg ohm) 300 M? 400 M? 500 M?

Insulation resistance varies inversely with temperature and is generally corrected to a standard temperature (usually 20°C) using table (Source: BHEL instruction Manual) as given below: Difference in temperatures ( °C)

Correction Factor (k)

10 20 30 40 50

1.65 2.6 4.2 6.6 10.5

(The measured value to be multiplied by the factor k i.e T20 = k*T measured)

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The ratio of 60 second insulation resistance to 15 second insulation resistance value is called dielectric absorption coefficient or Index (DAI). For oil filled transformers with class A insulation, in reasonably dried condition the absorption coefficient at 30°C will be more than 1.3. The polarization index test is performed generally by taking mega ohm readings at 1min and 10mim insulation resistance value. The polarization index is the ratio of the 10 min to the 1 min mega ohm readings. PI= R10 / R1 (dimensionless),Where PI is Polarization Index and R is resistance The following are guidelines for evaluating transformer insulation using polarization index values Polarization Index Less than 1 1.0-1.1 1.1-1.25 1.25-2.0 2.0 – 4.0 Above 4.0

Insulation Condition Dangerous Poor Questionable Fair Good Excellent

A PI of more than 1.25 and DAI of more than 1.3 are generally considered satisfactory for a transformer when the results of other low voltage tests are found in order. PI less than 1 calls for immediate corrective action. For bushings, an IR value of above 10,000 MÙ is considered satisfactory. 3.4

Capacitance and Tan ä measurement of Bushings Dissipation Factor Dissipation factor/loss factor (Tan delta) is defined as the ratio of resistive component (Ir) of current to that of capacitive current (Ic) flowing in an insulating material. Power Factor Power factor is the ratio of resistive current to that of total current. For very low value of resistive currents, values of dissipation factor and power factor are same (up to 2%). UST Test set connected for Ungrounded Specimen Test mode. This is used when specimen is isolated from earth e.g. Transformer bushing, CTs with test tap, CVTs and CB voltage grading capacitors. The test mode is often used to reduce the effect of stray capacitance losses to ground, and to reduce the effect of interference pickup from energized apparatus. GST Test set connected for grounded specimen test mode. This is used when specimen do not have two specific points (isolated from ground) for Tan delta measurement e.g. Transformer/Reactor winding, CTs without test tap etc. GSTg This test is used to separate the total values of a GST test into separate parts for better analysis. Often this test is used with GST test to confirm the test readings made using the UST mode


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TEST EQUIPMENT 10 KV or 12 KV fully automatic Capacitance and Tan delta test kit to be used for accurate measurement and repeatability of test results. TESTING PROCEDURE Typical arrangement for Tan d measurement is given below: Figure-6

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PRECAUTIONS a) b)

c) d) e) f) g) h)

There should be no joints in testing cables. HV lead should be screened with double shield and shields should not have internal shorting otherwise tests in GST/GSTg modes, shall not be possible. Check the same by Insulation Tester(100V) Test leads should not touch any live part. Never connect the test set to energized equipment The ground cable must be connected first and removed at last High voltage plugs should be free from moisture during installation and operation. Testing must be carried out by experienced/ certified personnel only. After testing with high voltage (10 kV), test terminals must be grounded before being touched by any personnel.

Ø For 3-Ph auto-transformer, short together all 400kV, 220kV and Neutral (isolated from earth) Bushings. Also short all 33kV Bushings and earth the same. Measurement of C1 Capacitance and Tand : Connect the crocodile clip of the HV cable to the top terminal of the shorted HV/IV bushings. Unscrew the test tap cover, Insert a pin in the hole of the central test tap stud by pressing the surrounding contact plug in case of 245 kV OIP Bushing and remove the earthing strip from the flange by unscrewing the screw (holding earth strip to the flange body) in case of 420 kV OIP Bushing. Connect the LV cable to the test tap (strip/central stud) of the bushing under test to the C & TANd KIT through a screened cable and earth the flange body. Repeat the test for all Bushings by changing only LV lead connection of the kit to test tap of the Bushing which is to be tested Measurement of C2 Capacitance and Tand : HV lead to be connected to the test tap of the bushing under test (if required additional crocodile type clip may be used) and LV of the kit to be connected to the ground. HV of the bushing is to be connected to the Guard terminal of the test kit. Test to be carried out in GSTg mode at 1.0kV. Ø For measurement of 33kV Bushing Tan Delta, earth HV/IV Bushings (already shorted). Apply HV lead of the Test kit to shorted 33kV Bushings and connect LV lead of the test kit to Test tap of the Bushing under test. Ø Measurements shall be made at similar conditions as that of a previous measurement. The oil-paper insulation combination of bushings exhibit fairly constant tan delta over a wide range of operating temperature. Hence, effort is to be made for testing at temperature near to previous test and correction factor need not be applied. Ø Do not test a bushing (new or spare) while it is in its wood shipping crate, or while it is lying on wood. Wood is not as good an insulator as porcelain and will cause the readings to be inaccurate. Keep the test results as a baseline record to compare with future tests. Ø It is to be ensured that C& Tan ä measurement of bushings and testing of turrets carried out before installation. This will prevent installation of bushings having C& Tan ä values beyond permissible limits. Pre-Commissioning Procedures For Switchyard Equipments

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Ø It is to be ensured that Test Tap points are earthed immediately after carrying out the measurements for that particular Bushing and earthing of test tap to be ensured by carrying out continuity test. Acceptable Limits: Bushing Tan ä should be less than 0.5% for all type of bushings. 3.5

CAPACITANCE AND TAN ä MEASUREMENT OF WINDINGS

The combination for C & tan measurement of winding is same as that of measurement of IR value. The summery of probable combination is given below. AutoTransformer (Two winding) HV + IV to LV HV + IV to E LV to E

Test Mode

Shunt Reactor

Test Mode

3 winding Transformer

Test Mode

UST GSTg GSTg

HV to E

GST

HV to LV1 HV to LV2 LV1 to LV2 HV to Ground LV1 to Ground LV2 to Ground

UST UST UST GSTg GSTg GSTg

Table 4: Combination for C & tan measurement of winding for various transformers/ Shunt Reactor

Ø Ensure that test specimen is isolated from other equipments. Removal of Jumpers from Bushings is Pre-Requisite for C & Tan ä Measurement of Windings. Ø For ICTs (Auto-Transformers): Shorting of all three phase Bushings (400kV&220kV) and neutral to be done. In case of single phase, 400kV, 220kV and neutral Bushings to be shorted Capacitance and Tan measurement of windings should be done in following combinations. Test No.

24

Winding Combination

Test mode

Cap Symbol

Test lead Connection

1.

HV-IV/LV

UST

C HL

2.

HV-IV/ LV+G

GST

C HL +C HG

-do-

3.

HV-IV / LV with Guard

GSTg

C HG

do--

4

HV-IV/LV

UST

C HL

GST

C HL +C LG

LV lead of test kit to HV/IV bushings of transformer HV lead of test kit to LV bushing of transformer -do-

Remarks

HV lead of test kit to HV/IV bushings of transformer LV lead of test kit to LV bushing of transformer LV to Guarded

be

5

LV/ HV-IV +G

6.

LV/ HV-IV with GSTg C LG -doHV to Guard Guarded Table 5:.Winding combination for C & tan ä measurement for auto transformer

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·

·

Measurement inter-check can be done by calculating C1= C2-C3 & C4= C5- C6 & DF1=C2DF2-C3DF3 / C2-C3= C4DF4-C5DF5 / C4-C5 Where C stands for capacitance and DF for dissipation factor or tan ä and attached suffix (1…6) denotes the sr. no. of test in above table. For Reactors: All 400kV and neutral Bushings to be shorted. HV of the test kit to be connected to shorted Bushings and LV of the test kit to be connected to Earth connection. Measure the Capacitance and tan Delta in GST mode. Neutral connection with earth/ NGR to be isolated before the test. Acceptable Limit: Winding Tan ä should be less than 0.5% in all combinations.

3.6

TURNS RATIO (VOLTAGE RATIO) MEASUREMENT Ratio measurements must be made on all taps to confirm the proper alignment and operation of the tap changers. The test should preferably be performed by automatic Transformer turns ratio (TTR) meter. Open turns in the excited winding will be indicated by very low exciting current and no output voltage. Open turns in the output winding will be indicated by normal levels of exciting current, but no or very low levels of unstable output voltage. The turns-ratio test also detects high-resistance connections in the lead circuitry or high contact resistance in tap changers by higher excitation current and a difficulty in balancing the bridge. Acceptable Limit: Results of the voltage ratio are absolute, and may be compared with the specified values measured during factory testing. The turns-ratio tolerance should be within 0.5 % of the nameplate specifications. For three phase Y connected winding this tolerance applies to phase to neutral voltage. If the phase-to-neutral voltage is not explicitly indicated in the nameplate, then the rated phase-to-neutral voltage should be calculated by dividing the phase-to-phase voltage by Ö 3.

3.7

VECTOR GROUP AND POLARITY

Polarity and phase-relation tests are of interest primarily because of their bearing on paralleling or banking two or more transformers. Phase-relation tests are made to determine angular displacement and relative phase sequence. Phase-relation or vector group verification test is performed on a three phase transformer or on a bank of three single-phase transformers. The details of Additive and Subtractive polarity are given in IS: 2026-Part 1 and IEC 60076-1.

1.1 1.2 Figure-7 Pre-Commissioning Procedures For Switchyard Equipments

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For a single-phase transformer having a ratio of transformation of 30 to 1 or less, the polarity test shall be done as follows. The line terminal of high voltage winding (1.1) shall be connected to the adjacent line terminal low-voltage winding (2.1) as shown in figure 7. Any convenient value of alternating voltage shall be applied to the full high-voltage winding and readings shall be taken of the applied voltage and the voltage between the right-hand adjacent high-voltage and low-voltage leads. When the later reading is greater than the former, the polarity is additive. When the later reading is less than the former (indicating the approximate difference in voltage between that of the high-voltage and low-voltage windings), the polarity is subtractive. The test shall be conducted with 3 phase, 415V supply. By the measured voltage data, it should be verified that the desired conditions of vector group and polarity are fulfilled Example for Y D11 -

Connect neutral point and LV phase with Earth Join 1R1 & 3R1 Terminals Apply 415 , 3-ö supply to HV Ensure 2R1-N=2Y1-N=2B1-N=Constant If 3R1-N>3Y1-N>3B1-N, and 3Y1-1B1>3Y11Y1 Vector group Yna0d11 is confirmed and polarity verified.

1R1 3R1 3Y1 3B1 2R1

2B1

2Y1

1B1

1Y1

Please Note: Most of the auto transformers in POWERGRID are of Yd11configuration.

3.8

MAGNETIC BALANCE TEST

This test is a low voltage test conducted at factory and site by applying single phase voltage between phase and neutral of a winding and measuring voltage induced in other two phases of the same winding. This test is carried out only in three phase units. Keep the tap in nominal tap position. Disconnect transformer neutral from ground. Apply single phase 230 V across one phase of Highest Voltage (HV) winding terminal and neutral (call it v1) then measure voltage in other two HV terminals across neutral (call them v2 and v3 respectively). Repeat the test for each of the three phases. Repeat the above test for Intermediate Voltage (IV) winding also. The identical results confirm no damage due to transportation. The following points may be noted. Transformer neutral should be disconnected from ground (i) No winding terminal should be grounded, otherwise results would be erratic and confusing. (ii) Zero voltage or very negligible voltage induced in any of the other two phases shall be investigated. (iii) It is proposed that a set of readings should be taken for information and comparison later during service of the transformer. 26


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Acceptable Limit: Also the applied voltage may be expressed as 100% voltage and the induced voltage may be expressed as percentage of the applied voltage. This will help in comparison of the two results when the applied voltages are different. The voltage induced in the centre phase shall be 50 to 90% of the applied voltage. However, when the centre phase is excited then the voltage induced in the outer phases shall be 30 to 70% of the applied voltage. Zero voltage or very negligible voltage induced in the other two windings should be investigated. 3.9

FLOATING NEUTRAL POINT MEASUREMENT

This test is conducted by applying 3 phase 415 volt supply across HV windings or IV winding as the case may be after disconnecting the transformer neutral from the ground. For a healthy transformer, when 3 phase balance voltage is applied, the voltage between neutral and ground is zero or otherwise a negligible voltage will appear. But in case there is a short circuited winding, the voltage between the neutral and the ground is appreciable. This test will also help in detecting the gradual deterioration or development of fault in the winding during service. Acceptable Limit For a healthy transformer the voltage between neutral and ground should be zero or negligible. In case, significant voltage appears between neutral and ground, matter to be referred to the manufacturer. 3.10

MEASUREMENT OF SHORT CIRCUIT IMPEDANCE

This test is used to detect winding movement that usually occurs due to heavy fault current or mechanical damage during transportation or installation since dispatch from the factory. Ensure the isolation of Transformer from High Voltage & Low voltage side with physical inspection of open condition of the concerned isolators/ disconnectors. In case tertiary is also connected, ensure the isolation of the same prior to commencement of testing The measurement is performed in single phase mode. This test is performed for the combination of two windings. The one of the winding is short circuited and voltage is applied to other winding. The voltage and current reading are noted. The test shall be conducted with variac of 0-280 V, 10 A, precision RMS voltmeter and ammeter. The conductors used for short-circuiting one of the transformer windings should have low impedance (less than 1m-ohm) and short length. The contacts should be clean and tight. Acceptable Limit: The acceptable criteria should be the measured impedance voltage having agreement to within 3 percent of impedance specified in rating and diagram nameplate of the transformer. Variation in impedance voltage of more than 3% should be considered significant and further investigated.


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3.11

EXCITING/ MAGNETISING CURRENT MEASUREMENT

This test should be done before DC measurements of winding resistance as saturation of winding due to the application of DC voltage may alter the test results. If there is suspected residual magnetism in the winding, transformer under test may be demagnetized before commencement of magnetizing current test. Three-phase transformers are tested by applying Single-phase 10 kV voltage to one phase (HV terminals) and keeping other winding open circuited and measuring the current at normal, minimum and max. tap positions. Keep the tap position in normal position and keep HV and LV terminals open. Apply 1phase 10kV supply on IV terminals. Measure phase to phase voltage between the IV terminals and current on each of the IV windings. Acceptable Limit: The set of reading for current measurement in each of the tap position should be equal. Unequal currents shall indicate possible short circuits in winding. Results between similar single-phase units should not vary more than 10 % .The test values on the outside legs should be within 15 % of each other, and values for the centre leg should not be more than either outside for a three-phase transformers. Results compared to previous tests made under the same conditions should not vary more than 25%. If the measured exciting current value is 50 times higher than the value measured during pre-commissioning checks, then there is likelihood of a fault in the winding which needs further analysis. The identical results confirm no damage due to transportation. The availability of test data of normal condition and faulty condition results help us to analyze the problem in future. 3.12

OPERATIONAL CHECKS ON OLTC

Following checks should be carried out during pre-commissioning: Ø Manual Operation: The tap changer has to be run manually by the hand crank through the total operating cycle. In each operating position, the position indicators of motor drive and tap changer (On TC head) show the same position. Ø Motor drive for step by step tap changing operation: Push button to be kept pressed till the motor stops i.e. driving motor should be automatically switched off when the tap changer has performed one switching operation be seen through the inspection glass in the tap changer head cover). (Note: At the time of change over selector operation (i.e. 9b to 10 & vice-versa), higher torque is required. Tap changer end position should be checked that the same is not overrun to avoid any failure during operation. Same can be seen through the inspection glass in the tap changer head cover). With the tap-changer fully assembled on the transformer the following sequence of operations shall be performed: a.

28

With the transformer un-energized, one complete cycles of operations (a cycle of operation goes from one end of the tapping range to the other, and back again). Check Pre-Commissioning Procedures For Switchyard Equipments

Doc No. D-2-01-03-01-03

continuity of winding during this test. Ensure that the voltmeter needle does not deflect to zero. Specify where and how to connect the analog Voltmeter. b.

With the transformer un-energised, and with the auxiliary voltage reduced to 85% of its rated value, one complete cycle of operation.

c.

With the transformer energized at rated voltage and frequency at no load, one complete cycle of operation.

The following additional check points/ guidelines for OLTC is recommended in consultation with OLTC manufacturer to ensure the absence of problems and proper operation:

3.13

a)

Function of control switches

b)

OLTC stopping on position

c)

Fastener tightness

d)

Signs of moisture such as rusting, oxidation or free standing water and leakages

e)

Mechanical clearances as specified by manufacturer's instruction booklet

f)

Operation and condition of tap selector, changeover selector and arcing transfer switches

g)

Drive mechanism operation

h)

Counter operation, Position indicator operation and its co-ordination with mechanism and tap selector positions

i)

Limit switch operation

j)

Mechanical block integrity

k)

Proper operation of hand-crank and its interlock switch

l)

Physical condition of tap selector

m)

Freedom of movement of external shaft assembly

n)

Extent of arc erosion on stationary and movable arcing contacts

o)

Inspect barrier board for tracking and cracking

p)

After filling with oil, manually crank throughout entire range

q)

Oil BDV and Moisture content (PPM) to be measured and recorded (Min BDV should be 60 KV and Moisture content should be less than 10 PPM)

TESTS/ CHECKS ON BUSHING CURRENT TRANSFORMERS (BCTS) Continuity, Polarity and secondary winding resistance tests of individual cores of Bushing Cts

3.14

OPERATIONAL CHECKS ON PROTECTION SYSTEM

(For detailed procedure, please refer to DOC NO: D-2-03-XX-01-01 Maintenance Procedures for Switchyard Equipments Part1: EHV Transformers/ Reactors) 1)

Operational Checks on Breathers (Conventional Silcagel or Drycol as supplied with the transformers).


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3.15

2)

Visual check of MOG of Main Conservator

3)

Marshalling Box & Kiosk Checks

4)

Valve Operational Checks

5)

Checks on Cooling System i.

Checks on cooling fans-rotation, speed & Control (Manual /temp /load) setting checks

ii.

Checks on Cooling pumps- rotation, vibration/noise, oil flow direction

6)

Checks on temperature Gauges (OTI/WTI-Calibration and Cooler Control, alarm & trip setting tests

7)

Checks on gas actuated (SPRs/ PRDs/ Buchholz) relays –Operational checks by simulation as well as shorting the respective contacts as applicable

8)

Checks on tightness of Terminal connectors - micro-ohm measurement of each connection

9)

Checks on Transformer/ Reactor protection (differential, REF, Over-current & stability tests etc.)

STABILITY OF DIFFERENTIAL, REF OF TRANSFORMER/ REACTOR

This test is performed to check the correctness of CT polarity, CT secondary core connections, connections at relay terminals and operation of relay under fault conditions. Here the entire electrical protection scheme is checked. 3.15.1

30

REF STABILITY TEST FOR TRANSFORMER

1)

After opening the Circuit Breaker and isolators at both side (H.V. and L.V. side) of transformer, use “Primary Test Tap (M point or PI1/PI2)” provided in the BUSHING TURRET CTs to bypass the Transformer with the help of Primary current injection leads. Now, after ensuring completion of all CT wiring & normal polarity, inject current with the help of Primary Injection kits in the relevant turret CTs of R phase & Neutral, subject to the maximum rating of Primary Test Tap.

2)

Measure the spill current in REF relay which should be nearly zero.

3)

Switch off Current Injection.

4)

Reverse the polarity of R phase Bushing CT and again start Current Injection. Appreciable spill current will appear in REF relay.

5)

Normalize the CT circuit which was reversed in step no. (4), after switching off Current injection.

6)

Repeat the same procedure for Y and B phases and note down the results in formats.

7)

Normalize the connections of CT.

8)

This test has to be performed from both HV side & LV side w.r.t. Neutral.


Doc No. D-2-01-03-01-03

However, if Primary Test Tap is not available in the Turret CTs, adopt following procedure: 1) After opening the Circuit Breakers and Isolators at both side (H.V. and L.V. side) of transformer apply 440V three phase voltage at three phase bushing of H.V. side with the help of three phase variac. 2) Earth the R phase of the LV side (through isolator earth switch or discharge rod). 3) Measure the spill voltage (in mV)/ spill current (in mA) at REF relay which should be nearly zero. 4) Switch off 440V supply. 5) Reverse the polarity of R phase Bushing CT and again switch on 440V supply. Appreciable spill voltage/ current will appear in REF relay. 6) Normalize the CT circuit which was reversed in step no. (5), after switching off 440V supply. 7) Repeat the same procedure for Y and B phases and note down the results in formats. 8) Normalize the connections of CT and remove feeding of three phase supply. 3.15.2 REF STABILITY TEST FOR REACTOR 1)

2) 3) 4) 5) 6) 7)

After opening the Circuit Breaker and Isolators of Reactor, use “Primary Test Tap (M point or PI1/PI2)” provided in the BUSHING TURRET CTs to bypass the Reactor with the help of Primary current injection leads. Now, after ensuring completion of all CT wiring & normal polarity, inject Current with the help of Primary Injection kits in the relevant Turret CTs of R phase of Reactor & earth side CT of NGR, subject to the maximum rating of Primary Test Tap. Measure the spill current in REF relay which should be nearly zero. Switch off Current Injection. Reverse the polarity of R phase Bushing CT and again start Current Injection. Appreciable spill current will appear in REF relay. Normalize the CT circuit which was reversed in step no. (4), after switching off Current injection. Repeat the same procedure for Y and B phases and note down the results in formats. Normalize the connections of CT.

However, if Primary Test Tap is not available in the Turret CTs, adopt following procedure: 1)

After opening the C.B. and isolators of Reactor, remove the jumpers of three phase bushings. Reactor Neutral will remain connected to NGR, however Earth connection of NGR Bushing will be opened.

2)

Apply 415 volts, phase to phase voltage across R phase bushing of Reactor & earth side Bushing of NGR, after ensuring completion of all CT wiring & normal polarity.

3)

Measure the spill voltage (in mV)/ spill current (in mA) in REF relay which should be nearly zero.

4)

Switch off 415V supply to Reactor / NGR Bushing.


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Doc No. D-2-01-03-01-03

3.16

5)

Reverse the polarity of R phase bushing CT.

6)

Switch on 415V supply to Reactor / NGR Bushing.

7)

Appreciable spill voltage/ current will appear in REF relay.

8)

Now normalize the polarity of the Bushing CT which was reversed in step (5).

9)

Repeat the same procedure for Y and B phase and note down the results in formats.

10)

After completing the test for all three phases normalize the reactor CT connection and jumpers & Earth connection of NGR Bushing.

FREQUENCY RESPONSE ANALYSIS (FRA) MEASUREMENT Frequency Response Analysis (FRA) is conducted to assess the mechanical integrity of the transformer which may get disturbed due to transportation shocks. FRA signatures will be taken after assembly and oil filling and compared with factory testing to ensure the healthiness of core /coil assembly during transportation. These signatures will be the benchmark for future reference. The FRA signatures should be analyzed in conjunction with Impact Recorder readings. Report of Impact recorder readings is to be obtained from manufacturer. It is recommended to follow the standard procedure for the SFRA measurement as per the Table-7. It should be done on maximum, normal and minimum tap of the transformer. Combination of tests for Auto Transformer Test Type Series Winding (OC) All Other Terminals Floating Common Winding (OC) All Other Terminals Floating Tertiary Winding (OC) All Other Terminals Floating Short Circuit (SC) High (H) to Low (L) Short (X1-X2-X3) Short Circuit (SC) High (H) to Tertiary (Y) Short (Y1-Y2-Y3) Short Circuit (SC) Low (L) to Tertiary (Y) Short (Y1-Y2-Y3)

Test Test 1 Test 2 Test 3

3Ô H1-X1 H2-X2 H3-X3

Test 4 Test 5 Test 6 Test 7 Test 8 Test 9 Test 10 Test 11 Test 12 Test 13 Test 14 Test 15 Test 16 Test 17 Test 18

X1-H0X0 X2-H0X0 X3-H0X0 Y1-Y3 Y2-Y1 Y3-Y2 H1-H0X0 H2-H0X0 H3-H0X0 H1-H0X0 H2-H0X0 H3-H0X0 X1-H0X0 X2-H0X0 X3-H0X0

1Ô H1-X1

X1-H0X0 Y1-Y2 (Y1-Y0) H1-H0X0 Short (X1-H0X0)

H1-H0X0 Short (Y1-Y2) X1-H0X0 Short (Y1-Y2)

Table-7: Various combinations for FRA measurement in Auto Transformer 32


Doc No. D-2-01-03-01-03

Combination of tests for Shunt Reactor In case of Shunt Reactor, FRA to be done in following combinations: Ø H1-H0 Ø H2-H0 Ø H3-H0 3.17

WINDING RESISTANCE MEASUREMENT

Preferably to be carried out using Automatic kit, in case of non availability V/I method can be adopted. To reduce the high inductive effect, it is advisable to use a sufficiently high current to saturate the core. This will reduce the time required to get a stabilized reading. It is essential that temperatures of the windings are accurately measured. Care shall be taken that self inductive effects are minimized. Care also must be taken to ensure that direct current circulating in the windings has settled down before the measurement is done. In some cases this may take several minutes depending upon the winding inductance. The winding resistance shall be preferably done when the difference in the top and bottom temperature of the winding (temperature of oil in steady-state condition) is equal to or less than 5C. The winding resistance should preferably be carried out last after completion of all other LV tests, as after this test core gets saturated and tests like magnetizing current, magnetic balance etc. carried out after winding test may be affected and indicate a misleading results, if the core is not de-magnetized before carrying out these tests. For star connected auto-transformers the resistance of the HV side is measured between HV terminal and IV terminal, then between IV terminal and the neutral AT ALL TAPS. The tap changer should be changed from contact to contact so that contact resistance can also be checked. Measurement of winding resistance is to be carried out from tap position 1 to 17 and again from 17 to 9. While doing measurements in reverse order, 2 to 3 steps shall be enough. During tap changing operation, continuity checks between HV to neutral to be carried out by analog multimeter while changing tap. For delta connected windings, such as tertiary winding of auto-transformers, measurement shall be done between pairs of line terminals and resistance per winding shall be calculated as per the following formula: Resistance per winding = 1.5 x Measured value Take the winding temperature reading while doing the resistance measurement. Calculate the resistance at 75°C as per the following formula R75 = Rt (235+75)/(235+t ),Where Rt = Resistance measured at winding temperature t


33

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Acceptable Limit: The resistance value obtained should be compared with the factory test value. Results are compared to other phases in Star-connected transformers or between pairs of terminals on a Delta–connected winding to determine if a resistance is too high or low. Because field measurements make it unlikely that precise temperature measurements of the winding can be made, the expected deviation for this test in the field is not more than 5.0% of the factory test value. 3.18

DISSOLVED GAS ANALYSIS (DGA) OF OIL SAMPLE

Dissolved Gas Analysis (DGA) is a powerful diagnostic tool to detect any incipient fault developing inside the oil-filled equipment. The oil sample is to be taken after oil filling (before commissioning ) as a benchmark and there after 24hrs of charging, 7 days, 15 days, one month and three months after charging to monitor the gas build up if any. The oil samples are to be sent to the designated labs for DGA and first two samples for oil parameter testing also. For detailed procedure for each test, please refer Transformer and Reactor Maintenance manual (Doc No. D-2-03-XX-01-01)-First Revision, Part B, C & D.

34


Doc No. D-2-01-03-01-03

CHECK LIST FOR ENERGISATION OF TRANSFORMER/ REACTOR 4.1

PRELIMINARY CHECKS

1.

Release air at the high points, like oil communicating bushings, buchholz petcock, tank cover and the cooling devices including headers, radiators, pumps, expansion joints etc. of the transformer. Air release should be resorted from low points to high points.

2.

Check the whole assembly for tightness and rectify where necessary.

3.

Check the general appearance and retouch the paint work if needed.

4.

Check that the valves are in the correct position : Ø Tank: valves closed and blanked Ø Cooling circuit: valves open Ø Conservator connection:valves open Ø By-pass: valves open or closed as the case may be. Ø On-load tap changer:valves open

5.

Check that the silica gel is completely filled in the breather and is blue and that there is oil in the breather cup (oil seal)

6.

Ensure that CC & CL are properly grounded.

7.

Check the oil level in the main conservator and the conservator of on-load tap changer, as per manufacturers recommendations

8.

Check the bushings: Ø Oil level ( bushings fitted with sight-glasses) Ø Adjustment of spark-gaps /arcing horn –gaps, if provided Ø Conformity of connection to the lines (no tensile stress on the terminal heads) Ø Bushing CT secondary terminals must be shorted and earthed, if not in use. Ø Neutral bushing effectively earthed Ø Tan delta cap should be tight and properly earthed.

9.

Check the on-load tap changer: Ø Conformity of the positions between the tap changer control cubicle and the tap changer head


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Ø Adjustment of the tap-changer control cubicle coupling Ø Electric and mechanical limit switches and protective relays Ø Step by step operation- local and remote electrical operation as well as manual operation and parallel operation, if any Ø Signaling of positions 10.

Check the quality of the oil: Ø Draw a sample from the bottom of the tank. Ø Carry out DGA and oil parameters test

11.

Prior to energization at site, oil shall be tested for following properties acceptance norms as per below generally in line with IS: 1866 / IEC 60422: 1. 2. 3. 4. 5. 6. 7.

8. · 12 13

4.2

&

Break Down voltage (BDV) : 70 kV (min.) Moisture content : 5 ppm (max.) Tan-delta at 90 °C : 0.01 (max.) Total Gas Content : < 1% Resistivity at 90 °C : 6 X 1012 ohm-cm (min.) Interfacial tension : 0.035 N/m (min.) *Oxidation Stability (Test method as per IEC 61125 method C, Test duration: 500 hour for inhibited oil) a) Acidity : 0.3 (mg KOH /g) (max.) b) Sludge : 0.05 % (max.) c) Tan delta at 90 °C : 0.05 (max.) * Total PCB content : Not detectable (2 mg/kg total)

*For Sr. No. 7 & 8 separate oil sample shall be taken and test results shall be submitted within 45 days after commissioning for approval of Powergrid Check that equalizing link between OLTC tank and Main tank is removed Extraneous materials like tools, earthing rods, pieces of clothes, waste etc. should be removed before energizing.

CHECKING OF AUXILIARY AND PROTECTIVE CIRCUITS

1.

Ensure that the temperature indicators are calibrated.

2.

Check the setting and working of the mercury switches of winding and oil temperature indicators

3.

Ensure presence of oil in the thermometer pockets. Ø Follow the same procedure for the thermal replicas

4. 36

Check the direction of installation of buchholz relay. Pre-Commissioning Procedures For Switchyard Equipments

Doc No. D-2-01-03-01-03

5.

7.

Check the operation of the buchholz relay and the surge protective relay of the tapchanger for: Ø Alarm and tripping Ø Protections and signals associated with these relays Check the insulation of the auxiliary circuits with respect to ground by 2 kV insulation tester for 1 min. It should withstand the test. Check the earthing of the tank and auxiliaries like cooler banks at two places.

8.

Measure the supply voltages of the auxiliary circuits

9.

Check the cooling system for the following:

6.

Ø Check the direction of installation of oil pumps Ø Check the direction of rotation of the pumps and fans Ø Check the working of the oil flow indicators Ø Check the setting of the thermal overload relays Ø Go through the starting up sequences, control and adjust, if necessary, the relay time delays 10.

Check that there is sufficient protection on the electric circuit supplying the accessories and tightness of all electrical connections

11.

Check the heating and lighting in the cubicles

12.

Check the schemes of differential protection, over-current protection, restricted earth fault protection, over-fluxing protection etc. With implementation of settings as recommended by CC/Engg

After the inspection / tests are completed, the transformer may be energized from the incoming side on NO LOAD, 400kV or 220kV. The initial magnetizing current at the time of switching will be very high, depending upon the particular moment in the cycle. The transformer should be kept energised for twelve hours before taking on load. During this time, vibrations, abnormal cracking noise, etc. are to be observed. After that it may be checked for gas collection. If the gas prove to be inflammable, try to detect the cause which may probably be an internal fault. If the breaker trips on differential /REF, buchholz or any other protective device, the cause must be investigated thoroughly before re-energizing the transformer/ reactor. After successful charging, performance of transformer / rector should be checked under loading; OTI/WTI readings should be monitored for 24 hours and ensured that they are as per loading. DGA samples may be sent as per Standard practice (after 24 hrs of energizing, one week, 15 days, one month and three months after charging, thereafter as per normal frequency of 6 months). Loading data may be forwarded to CC/OS and manufacturer (if requested by them).


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POST COMMISSIONING CHECKS/TESTS FOR TRANSFORMERS AND REACTORS Sr. No.

Name of Test/ Check point

Purpose of test/ check

5.1

Thermovision Infrared scanning (IR thermography)

A thermo vision Camera determines the temperature distribution on the surface of the tank as well as in the vicinity of the Jumper connection to the bushing. The information obtained is useful in predicting the temperature profile within the inner surface of tank and is likely to provide approximate details of heating mechanism.

5.2

On Line moisture measurement

To determine the moisture content in paper insulation by measuring % Relative Saturation/ Active Water. This test to be carried out once the Transformer/ Reactor is stabilized and operating at higher temperature (>60 deg C).

5.3

Vibration measurement of Oilimmersed Reactor

To measure the vibrations of core /coil assembly in the tank of the reactor. Movement of the core-coil assembly and shielding structure caused by the time–varying magnetic forces results in vibration of the tank and ancillary equipment. These vibrations have detrimental effects such as excessive stress on the core-coil assembly

5.1

THERMOVISION SCANNING (IR THERMOGRAPHY)

Once the transformer/ reactor is charged and loaded, Thermovision scanning is to be carried out to see any hotspots. Thermovision scanning of transformer to be done at least after 24 hrs. of loading and repeated after one week. 5.2

On Line moisture measurement

5.3

VIBRATION MEASUREMENT OF OIL-IMMERSED REACTOR

Movement of the core-coil assembly and shielding structure caused by the time –varying magnetic forces results in vibration of the tank and ancillary equipment. These vibrations have detrimental effects such as excessive stress on the core-coil assembly. The shunt reactor under test shall be completely assembled in normal operating condition with cooling equipments, gauges and accessories. The shunt reactor shall be energized at rated voltage and frequency. Three phase excitation for 3-ph units. The shunt reactor should be mounted on a level surface that will provide proper bearing for the base, in order to eliminate the generation of abnormal tank stresses. The vibration of shunt reactor shall be measured by transducers, optical detectors or equivalent measuring devices. The measuring equipment should be accurate within +/- 10 % at 2nd harmonic of the exciting frequency. The peak-to-peak amplitude shall be determined by direct measurement or calculated from acceleration or velocity measurement. The average amplitude of all local maximum points shall not exceed 60 µm (2.36 mils) peak to peak. The maximum amplitude within any individual reading shall not exceed 200 µm (7.87 mils) peak to peak. 38


Doc No. D-2-01-03-01-03

PRE-COMMISSIONING CHECKS/TESTS FOR OTHER SWITCHYARD EQUIPMENTS Once erection is completed, various pre-commissioning checks/ tests are performed to ensure the healthiness of the switchyard equipments prior to their energisation. Various major electrical tests to be performed and their significance are given below: Sr. No.

Name of Test / Check point

6.1

Tan ä & Capacitance measurement of CT, each stack of CVT & total capacitance, CB voltage grading capacitor & each stack of Surge Arresters

6.2

Checks/ Tests applicable for CTs

6.2.1

Polarity test for CT

To ascertain whet her the polarity markings are correct or not as per drawing.

6.2.2

Magnetization characteristics of CT

To prove that the turns of CTs secondary windings are not short circuited and to check healthiness of CT cores. The magnetizing currents at KPV (Knee point voltage) shall be less than the specified value. The ratio of secondary and primary voltage shall also be measured.

6.2.3

Ratio test for CT

The ratio errors of the primary to the secondary currents should within specified ratio errors.

6.2.4

IR measurement of CT Changes in the normal IR value of CT indicate abnormal (Primary & Secondary conditions such as presence of moisture, dirt, dust, crack in insulator of CT and degradation of insulation. windings)

6.2.5

DGA test of CT oil

6.3 6.3.1

Checks/ Tests applicable for Circuit Breakers

6.3.2

Measurement of Circuit To measure closing/ tripping/ CO timings. These timings

Purpose of test/ check The purpose of the dissipation factor measurement of high voltage insulation is to detect incipient weaknesses in HV insulation. The most important benefit to be gained from this measurement is to obtain a “benchmark reference reading” on costly and high voltage equipment when the equipment is new and insulation is clean, dry and free from impurities. Tan delta & Capacitance values shall be comparable with factory test results and in no case shall be more than 0.5 %.

This test shall be conducted after 30 days of commissioning. The purpose is to identify evolving faults in the CT and DGA values shall be comparable with factory values (if available)

Dew point measurement Dew point of SF6 gas is to measure moisture content in of SF6 gas SF6 gas which shall indicate whether CB evacuation is done properly or not. This test shall be carried out preferably at rated pressure of SF6 gas.


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Breaker Operating should be within permissible limits and shall be comparable Timings including PIR with factory values. Pole discrepancies and Break to Break Timings discrepancies shall be less than specified values. 6.3.3

DCRM Contact Travel Measurement / DC injected currents and trip/ close coil currents.

6.3.4

Operational lockout To ensure various lockout operation of CB by simulating checking for EHV the actual conditions at the specified pressure of oil/ air/ operating medium. Circuit Breakers

6.3.5

Measurement of static This test is conducted to evaluate healthiness of Main contact resistance contacts. 100 Amp DC is injected and voltage drop is measured across each CB contact to compute contact resistance.

6.3.6

Checking the Pumping feature

6.3.7

Checking the Anti- To check correct operation of Thermostat provided for anti Condensation Heaters condensation heaters.

6.3.8

Pole discrepancy relay To test tripping of CB in case of pole discrepancy more testing than 2.5 seconds or specified value.

6.3.9

Checking the priming pressure

6.4

Checks/ Tests applicable for CVTs

6.4.1

CVT polarity, Ratio test

6.4.2

Insulation resistance Changes in the normal IR value of CVT indicate abnormal measurement of Primary conditions such as presence of moisture, dirt, dust, crack in & secondary winding insulator of CVT and degradation of insulation.

6.5

Checks/ Tests applicable for Isolators

6.5.1

MILLIVOLT Drop test

The voltage drop give s a measure of resistance of current carrying part and contacts by injecting minimum 100 A DC current.

6.5.2

50 operation tests

To test operation of contacts etc with jumpers connected and contact resistance to be measured after 50 operations. There shall not be any change from the previous value.

40

DCRM is the technique for measuring Contact Resistance during operation (Close/ Trip) of a circuit breaker with a delay Tco of 300ms. A DC current of at least 100 Amp is injected through the circuit breaker. The current and voltage drop are measured and resistance is calculated. The resistance and travel versus time data provides useful information on the condition of the circuit breaker contacts and is used as a diagnostic tool. DCRM test signatures shall be approved by Corporate OS.

Anti- By giving simultaneous close/ trip commands, CB hunting shall not take place by operation of Mechanical/ Electrical anti pumping feature.

N2 This test is to check healthiness of N2 accumulators provided in Hydraulic drive mechanisms. N2 priming pressure shall be as per the rated pressure. This test is c onducted in the same manner as for CT to determine correct CVT polarity, ratio and phasor group.


Doc No. D-2-01-03-01-03

6.6

Checks/ Tests applicable for Surge Arrestors

6.6.1

Third Resistive (THRC) arrestors

6.6.2

IR measurement of each Changes in the normal IR value of LA indicate abnormal stack of LA conditions such as presence of moisture, dirt, dust, crack in insulator of LA and degradation of insulation.

6.6.3

Checking of operation of This test is done to check the healthiness of LA counter. LA counter

6.7

Checks/ Tests for other areas/ equipments

6.7.1

Earth resistance To ensure value of earth resistance is below 1 ohm. measurement

6.7.2

Secondary injection test

6.7.3

Contact Tightness check of Bay contacts by Primary injection method

Harmonic To monitor healthiness of Surge arrestors by monitoring Current third harmonic resistive current from the leakage current. for surge This test is to be conducted after charging of Las. The value of THRC shall be less than 30 µA.

current Conducted for testing of protecting devices, circuit breakers, trip coils, motor overloads etc. Since complete bay contact resistance measurement is practically not possible because DC current may not be injected in CT primary, hence contact tightness check by primary injection method has been introduced to check overall contact tightness.


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6.1

TAN DELTA & CAPACITANCE MEASUREMENT OF CT, CVT, CB VOLTAGE GRADING CAPACITORS AND LA STACKS To measure dissipation factor/loss factor (Tan delta) and Capacitance measurement of EHV class CTs, CVTs, CB Voltage Grading Capacitors & LA stacks by applying test voltages up to 10kV. A)

CURRENT TRANSFORMERS

CTs with test taps 1. 2.

7.

Tan delta tap to be disconnected from ground. High voltage lead from tan delta kit to be connected to primary(HV) Terminal and LV lead to be connected to the Tan delta test tap. P1 and P2 to be shorted Porcelain surface to be thoroughly cleaned. Measurements have to be taken in UST mode with fully automatic test kit. Standard procedure(as specified by kit supplier) for measuring capacitance and tan delta in charged switchyard/induced voltage conditions should be followed for measurement of capacitance and tan delta values. It is to be ensured to connect the test tap to ground terminal after carrying out the test.

B)

CB VOLTAGE GRADING CAPACITOR

1. 2. 3. 4. 5.

7.

Connect LV cable to the middle of the double interrupter. Connect HV cable to the other end of the Grading capacitor to be tested. The opposite end of the grading capacitor has to be grounded using earth switch. Measurements have to be taken in UST Mode with fully automatic test kit. Disconnect the HV cable and connect the same to the other grading capacitor and ground the previous grading capacitor. Now the second grading capacitor is ready for testing. Standard procedure (as specified by kit supplier) for measuring capacitance and tan delta in charged switchyard/induced voltage conditions should be followed Measurements are to be carried out at 10 kV/ 12 KV.

C)

CAPACITOR VOLTAGE TRANSFORMERS

1.

Testing procedure for Top and Middle Stacks: (a) Apply 10 KV between flanges of Top/Middle stacks (whichever is being tested) (b) Carry out measurements in UST mode at 10.0 KV (c) While measuring Middle/ Bottom stacks, Top/ middle stacks to be shorted.

2.

Testing procedure for Bottom Stack connected to EMU PT (a) Connect HV of the test kit at the top flange of bottom stack. HF point to be grounded. Earth connection of the neutral of the PT to be opened/ isolated from ground. (b) Top of CVT to be guarded. LV lead of the kit to be connected at the top of the CVT for guarding.

3. 4. 5. 6.

6.

42


Doc No. D-2-01-03-01-03

(c) (d) (e) (f) 3.

Standard procedure (as specified by kit supplier) for measuring capacitance and tan delta in charged switchyard/ induced voltage conditions should be followed.

D)

SURGE ARRESTERS

1.

Testing procedure for Top, Middle and Bottom Stacks: (a) Apply 10 KV between flanges of Top/Middle/ Bottom stacks (whichever is being tested) (b) Carry out measurements in UST mode at 10.0 KV with fully automatic test kit. (c) While measuring Middle/ Bottom stacks, the stacks above the HV lead to be shorted.

2.

Standard procedure (as specified by kit supplier) for measuring capacitance and tan delta in charged switchyard/ induced voltage conditions should be followed.

3.

While doing measurement of bottom stack the earth connection to be removed.

6.2 6.2.1

Carry out measurements in GSTg mode at 10.0 KV Repeat the Test with neutral of PT connected to ground. In case Tan delta value is negative or erratic, only capacitance values are to be monitored. Measurement to be carried out using fully automatic kit.

CHECKS/ TESTS APPLICABLE FOR CTs POLARITY TEST FOR CT A centre zero voltmeter is connected across CT secondary. A 1.5 Volt battery is touched to primary of CT. The deflection of pointer should be similar in case of each CT core. At any instant current entering the primary from P1 the current should leave secondary from the terminal marked S1. A setup shown in the Figure 9 can show whether the polarity markings are correct or not. When the key is pressed, current enters the primary through terminal P1, the voltmeter connected as shown, should read positive. A general arrangement of polarity test setup is indicated in Fig. 10. P2

R

S2

B

Y P1

P1

P1

KEY

-

V

1.5 V

+

+ P1

+

S1

+ S2

V -

S1

Figure - 9 Pre-Commissioning Procedures For Switchyard Equipments

Figure - 10 43

Doc No. D-2-01-03-01-03

6.2.2

MAGNETIZATION CHARACTERISTICS OF CTs PRECAUTIONS a) b)

There should be no joints in testing leads/cables. It should be ensured that whole testing equipment along with testing procedures are available at testing site. Testing must be carried out in presence of testing personnel only.

Test Equipment: Voltage source of 5 kV, Voltmeter of range 0 to 5 kV, Ammeter, of range 0 to 500 Amps, testing leads/cables etc. Test Procedure: Make connections as per diagram shown below (Fig- 11). After making proper connections, applied voltage is increased from zero to rated Knee Point Voltage in steps of 25%, 50%, 75% and 100%. Measure the current drawn by the CT secondary core at respective applied voltages and record the test results

A

0-500 mA

V

5 kV

0- 5 kV

Figure - 11

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Doc No. D-2-01-03-01-03

Knee Point Voltage is normally defined as the voltage at which 10% increase in the applied voltage causes 30 to 50% increase in secondary current. The magnetization current at rated Knee Point Voltage should not be more than the specified/designed value. A curve can be drawn between applied voltage and magnetizing current. Typically, the curve drawn should be like the one given below in Fig.-12.

600 10 %

VOLTAGE

500 400

300 30 % 200

100

MAGNETIZING CURRENT

TYPICAL MAGNETIZATION CURVE

Figure - 12 From the curve it can be implied that up to rated KPV (Knee Point Voltage), the VI curve should be almost a straight line. However, if this line is not linear, this indicates that the magnetizing characteristics are not desirable. If the slop of the curve starts increasing, it indicates that magnetizing induction becomes low and total primary current is utilized in exciting the core alone. Consequently, out put of CT secondary disappears. 6.2.3

RATIO TEST FOR CURRENT TRANSFORMER The ratio check has to be carried out as indicated in Fig-13 below. A1

PRIMARY CURRENT INJECTION SET

A2 A1 : PRIMARY CURRENT A2 : SECONDARY CURRENT

Figure - 13 It is customary to conduct this in conjunction with the primary injection test. Current is passed through the primary circuit with the secondary winding circuit to its normal circuit load. The ratio of the primary to the secondary currents should approximate closely to that stamped under CT identification plate. Pre-Commissioning Procedures For Switchyard Equipments

45

Doc No. D-2-01-03-01-03

Alternatively, ratio test is to be conducted as per the following method (Fig-14).

A

V1 V2

Figure - 14 Apply voltage from secondary of the CT and measure voltage in primary winding. Increase voltage in secondary up to rated KPV/ ISF and by recording Primary Voltage, compute ratio of V1/ V2. The ratio should match with the specified value. 6.2.4

INSULATION RESISTANCE MEASUREMENT OF CURRENT TRANSFORMER

PRECAUTIONS

46

a)

There should be no joints in testing cables.

b)

Test leads should not touch any live part.

c)

Megger body should be earthed (if separate terminal is provided).

d)

Surface/terminals should be cleaned.

e)

IR measurement should be carried out preferably in dry and sunny weather.

f)

Never connect the test set to energized equipment.

g)

The ground terminal must be connected first and removed at last.

h)

High voltage plugs should be free from moisture during installation and operation.

i)

If oil traces are found on the surface of CT, the same should be cleaned by Methyl Alcohol only. Petrol or diesel should never be used.

j)

It should be ensured that whole testing equipment along with testing procedures are available at testing site. Testing must be carried out in presence of testing engineer only.

k)

After testing with high voltage, test terminals must be grounded before being touched by any personnel.

l)

Test leads should be properly screened/ shielded.


Doc No. D-2-01-03-01-03

Connect the Megger as per figure-15 given below. Connect the HV terminal to the Primary terminal of CT by using crocodile clip for firm grip

HV LV IR Test Kit

Figure-15 Typical Arrangement for IR measurement Carry out the measurement as per standard procedure given by the kit supplier. A test voltage as specified is applied as per the above connections and successive readings are taken. Values of IR should be recorded after 15 seconds, 60 seconds and 600 seconds. Ambient temperature and weather conditions are to be recorded. 6.2.5

DGA Test of CT Oil: Oil samples to be collected in 300ml bottles and to be sent to CIOTL Hyderabad for testing. Test results should be comparable to factory values. In case of any deviation, test results to be forwarded to CC-OS for approval.

6.3

CHECKS/ TESTS APPLICABLE FOR CIRCUIT BREAKERS

6.3.1

DEW POINT MEASUREMENT OF SF6 GAS FOR CIRCUIT BREAKER Dew Point is the temperature at which moisture content in SF6 gas starts condensing. Dew Point at rated pressure of CB: Dew Point when measured keeping regulating valve in service at the outlet of dew point kit to allow required flow rate of gas, is called at rated pressure of CB. Inlet valve is opened completely. Dew Point at atmospheric pressure : Dew Point when measured by regulating the gas flow at the inlet of dew point kit and keeping outlet regulating valve ( if provided) in fully open condition so that flow rate of gas is maintained as required, is called at atmospheric pressure. TESTING PROCEDURE a)

Make the connections to the kit from CB pole ensuring that regulating valve is fully closed at the time of connections of the Dew Point kit.

b)

By regulating the flow rate of SF6 gas (0.2 liter/min to 0.5 liter/min - ref. IEC 60480), the value of dew point is observed till it becomes stable.


47

Doc No. D-2-01-03-01-03

If the regulating valve is provided at outlet of the dew point kit then values as given in Doc. no. for rated pressures are to be monitored.

c)

Dew Point of SF6 gas varies with pressure at which measurement is being carried out. This is due to the fact that Saturation Vapour Pressure decreases with increase in Pressure of the SF6 gas. Hence, dew point of SF6 gas at higher pressure is lower than dew point at atmospheric pressure Therefore, it is to be ensured that if measurement has been done at a pressure other than the atmospheric pressure, same is to be converted to the atmospheric pressure as given in the table below used at the time of commissioning for various CB manufacturers: Method for converting dew point at different gas pressures, is given/described in IEC-60480. Sl. No.

6.3.2

1 2 3

Make of CB BHEL M&G CGL

4 5

ABB NGEF

Dew point at rated pressure (-) 15° C (-) 15° C (-) 15° C (-) 15° C

Dew point at Atmospheric Pressure ( Limit ) - 36° C - 39° C - 35° C - 35° C - 36° C

MEASUREMENT OF CIRCUIT BREAKER OPERATING TIMINGS INCLUDING PRE INSERTION RESISTOR TIMINGS PRECAUTIONS a) b) c) d) e) f) g) h) i) j)

There should not be any joint in testing cables. Test leads should not touch any live part. Never connect the test set to energised equipment. The ground cable must be connected first and removed at last. High voltage plugs should be free from moisture during installation and operation. Circuit Breaker Analyser body should be earthed (if separate earth is provided). It should be ensured that whole testing equipment along with testing procedures are available at testing site. Testing must be carried out in presence of testing personnel only. Surface/terminals should be cleaned where the connections for testing are to be made. Clean earth point with sand paper/wire brush where earth terminal is to be provided. Ensure that all the poles trip simultaneously through single close/trip command.

TESTING PROCEDURE a)

b) c) d)

48

Make connections as shown in the figure-16 below. It is to be ensured that R, Y, B phase marking cables are connected with the proper place in the CB analyser and colour codes are to be maintained for all the three poles of CB. Make connections for recording operating timings of Auxiliary contacts. Extend power supply to Circuit Breaker Analyzer. Give closing command to closing coil of CB and note down the PIR and main contact closing time. Take the print out from the analyzer. Pre-Commissioning Procedures For Switchyard Equipments

Doc No. D-2-01-03-01-03

e) f) g)

h)

Give tripping command to trip coil-I of CB & note down the main contact tripping time. Give tripping command to trip coil-II of CB & note down the main contact closing time. Note down the timings for `CO', and `OCO' by giving respective commands. CO command to be given without time delay but 300ms time delay to be given between O and CO operation in testing for OCO. To find out opening time of PIR contacts, PIR assembly has to be electrically isolated from Main contacts and then PIR contacts are to be connected to separate digital channels of the Analyzer.

EVALUATION OF TEST RESULTS A)

CLOSING TIMINGS

Closing timings and Discrepancy in operating times of PIR and main contacts should not exceed the permissible limits as specified in the DOC NO: D-5-02-XX-01-03. In any case, main contacts should not close prior to closing of PIR contacts and PIR contacts should not open prior to closing of main contacts. In case, contact bouncing is observed in operating timings for PIR and main contacts, same should be rectified by tightening the cable connections.

Main Contact

Black PIR Green

CB Analyser Red

Typical Arrangement for Operating Timings Measurement of CB

Figure - 16 B)

TRIPPING TIMINGS

Trip time and pole discrepancy in operating timings should not exceed beyond permissible value given in Doc. No. D-5-02-XX-01-03. In case of ABB, NGEF and CGL make CBs, while tripping, PIR contacts should not open after opening of main contacts.


49

Doc No. D-2-01-03-01-03

C)

'CO' TIMINGS

CO timings should be within permissible limits as specified by different manufacturers. If operating timings of CB poles are not within limits, same may be corrected by: 1. Equalizing the SF6 gas pressure in all the poles 2. Adjusting plunger movement of trip/ close coils 3. Adjustment in operating mechanism 4. Changing of trip/ close coils (if required) It is also important to measure timings of auxiliary contacts from the point of view of variations w.r.t. the main contacts. 6.3.3

DYNAMIC CONTACT RESISTANCE MEASUREMENT (DCRM) AND CONTACT TRAVEL MEASUREMENT OF EHV CIRCUIT BREAKERS Test Equipment: 100 Amp. DCRM kit with CB operational analyzer with 10k Hz sampling frequency. Isolation Required a) CB should be in open position. b) Isolator of both sides of CB should be in open position. c) Earth switch of one side of CB should be in open position. Precautions a) There should be no joints in testing leads/cables. b) It should be ensured that whole testing equipment along with testing procedures are available at testing site. Testing must be carried out in presence of testing personnel only. c) Current leads should be connected such that voltage leads are not outside area of current flow. Testing Procedure 1. Follow the standard procedure as given in instruction manual of DCRM kit. 2. The tightness of connections at CB flanges is most important to ensure error free measurement. CB during CO operation generates lot of vibrations and failure of connections during this period can dramatically change the dynamic signature of CB resistance. 3. DCRM signatures should be recorded for CO operation. Open command should be extended after 300 ms from the close command. 4. Clean portions of incoming and outgoing flanges of CB with polish paper to remove paint, oxidation etc, at points where Current clamps are mounted. 5. Select this point of connection, as close as possible to the end of porcelain insulator to ensure that minimum resistance is offered by flanges, bolts, terminal connectors etc. 6. It should be ensured that Travel Transducers are properly fitted. 7. Sampling frequency during measurement should be 10 KHz. 8. Resistance, travel, injected current and Trip/ Close coil currents are to be recorded.

50


Doc No. D-2-01-03-01-03

The variations in the measured resistance versus time will be seen as a finger print for the breaker contacts and can be used as a bench mark for comparing with future measurements on the same breaker. This provides information on the condition of the breaker contacts, driving mechanism, operating levers etc. Dynamic Contact Resistance Measurement for CB healthiness By application of Dynamic Contact Resistance Measurement, condition of arcing contact, main contact, operating levers, driving mechanism can be predicted. If DCRM signature shows vide variations and also there is change in arcing contact insertion time, it indicates erosion of the arcing contacts to main contacts and subsequent failure. Contact Travel Measurement Transducers are attached to the operating rod or interrupting chamber in order to record the contact travel. When CB closes, contact travel is recorded. Contact bounces or any other abnormality is also clearly indicated by the Contact Travel Measurement. If contact travel, contact speed and contact acceleration signature are compared with the original signatures, then it may indicate problems related with the operating mechanism, operating levers, main/ arcing contacts, alignments etc. DCRM along with Contact Travel measurement is useful in monitoring length of Arcing contacts. Erosion of Arcing contacts may lead to commutation failures and current may get transferred to Main contacts. Due to heat of arc, main contacts may get damaged. 6.3.4

OPERATIONAL LOCKOUT CHECKING FOR EHV CIRCUIT BREAKERS

6.3.4.1 TESTING PROCEDURE: A.

SF6 GAS PRESSURE LOCKOUT a)

LOW PRESSURE ALARM

Close Isolation Valve between CB Pole(s) and density monitor. Start releasing SF6 gas from density monitor till the low pressure gas alarm contacts are actuated which is detected by Multimeter. Note down the pressure and temperature at which the contacts get actuated. b)

OPERATIONAL LOCKOUT:

Continue releasing SF6 gas from isolated zone till the operational lockout Alarm Contacts are actuated which are detected by Multimeter. Note down the pressure and temperature at which the contacts get actuated. This is called operational lockout pressure. B.

PNEUMATIC OPERATING SYSTEM LOCKOUT a)

COMPRESSOR START/STOP SWITCH

Close the isolating valve of CB. Release air into atmosphere from the compressor. Note down the value of pressure at which Compressor starts building up air pressure and pressure at which Compressor stops. Pre-Commissioning Procedures For Switchyard Equipments

51

Doc No. D-2-01-03-01-03

b)

CB AUTO RECLOSE LOCKOUT

Close isolation valve between pneumatic system and pressure switches. Release air from the isolated zone to atmosphere. Note down pressure at which A/R L/O contacts of pressure switch get actuated which are detected by Multimeter. The leads of the Multimeter should be connected to the contactor where the AR L/O of CB are made. c)

CB CLOSING LOCKOUT

Release air from the isolated zone to atmosphere. Note down pressure at which CB Closing L/O contacts of pressure switch get actuated which are detected by Multimeter. d)

CB OPERATIONAL LOCKOUT

Release air from the isolated zone to atmosphere. Note down pressure at which CB Operational L/O contacts of pressure switch get actuated which are detected by Multimeter. e)

MECHANICAL CLOSING INTERLOCK (FOR ABB & BHELCBs ONLY)

CB should be in closed position. Release air from pneumatic system of CB to atmosphere and observe whether CB poles start opening, if so, note down the pressure at which tie rod starts coming down. In such case the closing interlock is to be opened for inspection and if required, replace the closing interlock. C.

HYDRAULIC OPERATING SYSTEM LOCKOUT a)

Pump START/STOP

By opening pressure release valve, note down the pressure at which Pump starts building up oil pressure and pressure at which pump stops. b)

CB AUTO RECLOSE LOCKOUT

Close Isolation valve between hydraulic system and pressure switches. Release oil from the isolated zone to oil tank. Note down pressure at which A/R L/O contacts of pressure switch get actuated which are detected by Multimeter. c)

CB CLOSING LOCKOUT

Release oil from the isolated zone to oil tank. Note down pressure at which CB Closing L/O contacts of pressure switch get actuated which are detected by Multimeter. d)

CB OPERATIONAL LOCKOUT

Release oil from the isolated zone to container. Note down pressure at which CB Operational L/O contacts of pressure switch get actuated which are detected by Multimeter. D.

OPERATING PRESSURE DROP TEST:

For Pneumatic/ Hydraulic operating system, operating pressure drop test to be performed during OCO operation of CB, keeping AC supply of Hydraulic pump/ Compressor in off condition. Hydraulic/ Pneumatic pressure drop should be within limits (as recommended by Manufacturer)

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Doc No. D-2-01-03-01-03

6.3.4.2 EVALUATION OF TEST RESULTS A.

SF6 GAS PRESSURE LOCKOUT

All the SF6 gas pressure switches settings should be checked and corrected with ambient temperature. Settings of SF6 gas pressure switches should be within ± 0.1 bar/ Kg/cm2 of the set value ( after taking into account the temperature correction factor). B.

AIR PRESSURE LOCKOUT

All the air pressure switches settings should be checked and corrected and should be within ± 0.3 bar/ Kg/cm2 of the set value. C.

OIL PRESSURE LOCKOUT

All the oil pressure switches settings should be checked and corrected and should be within ± 0.3 bar/ Kg/cm2 of the set value. 6.3.5

MEASUREMENT OF STATIC CONTACT RESISTANCE The Static contact resistance of main circuit of each pole of a circuit breaker is of the order of a few tens of micro ohms. 100 A DC is injected and milli volt drop is measured across each CB contact to compute contact resistance. The values should be within specified limits as given in Doc No. D-5-02-XX-01-01.

6.3.6

CHECKING THE ANTI-PUMPING FEATURE When the breaker is in open position and closing and opening commands are given simultaneously the breaker first closes and then opens, but does not reclose even though the closing command is maintained.

6.3.7

CHECKING THE ANTI-CONDENSATION HEATERS Check the supervisory circuit of the anti-condensation heaters for correct functioning. With the heaters switched ON, measure their current output.

6.3.8

POLE DISCREPANCY RELAY TESTING Pole Discrepancy is defined as the difference in closing & opening timings of different poles of CB. A.

WHEN CB IN OPEN POSITION

Closing Command is extended to close one pole, say R-Pole, of CB. After closing R-Pole of CB, this Pole should automatically open after 2.5 seconds (as per pole discrepancy timer settings). Repeat the test for remaining two poles of CB.


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Doc No. D-2-01-03-01-03

B.

WHEN CB IN CLOSED POSITION

Tripping Command is extended to trip one pole, say R-Pole, of CB. Remaining Y and B- Poles of CB should automatically open after 2.5 seconds. Repeat the same test for remaining two poles of CB. C.

EVALUATION OF TEST RESULTS

Permissible value of pole discrepancy between two poles of CB is 3.33 msec. from system point of view and it should not be confused with the setting of pole discrepancy timer which is generally 1.0 or 2.5 sec. depending on Auto-reclose scheme. 6.3.9

CHECKING THE NITROGEN PRIMING PRESSURE

150

160

170

180

190

200

210

220

230

bar

Close the pressure release valve. Shortly after the oil pump starts, the priming pressure (200 bar at 20C) in the accumulator can be read. The relationship between the pressure and temperature is indicated in Fig. 17.

Priming pressure as a function of the temperature Nominal rating at 20 deg.C: 200.1 bar

Figure - 17 6.4

CHECKS/ TESTS APPLICABLE FOR CVTs

6.4.1

CVT POLARITY, RATIO TEST CVT polarity is checked in the same manner as for CT, taking care to ensure that the battery is connected to the primary winding. In case of star/star winding configuration care has to be taken to ensure that the primary and secondary neutral points are not connected together. It is necessary to verify that the phase rotation sequence of the 3 phase CVT is correct. The secondary voltage between phases and neutral are measured and then phase rotation meter is connected across the three phase terminal.

6.4.2

54

INSULATION RESISTANCE MEASUREMENT OF PRIMARY & SECONDARY WINDING Pre-Commissioning Procedures For Switchyard Equipments

Doc No. D-2-01-03-01-03

6.5

CHECKS/ TESTS APPLICABLE FOR ISOLATORS

6.5.1

MILLI VOLT DROP TESTS The milli volt drop across the isolator is measured using DC current. The voltage drop gives a measure of resistance of current carrying part and contacts. The DC current should be equal to or more than 100 A. The resistance of isolator should be measured at ambient air temperature. The temperature of specimen/environmental temperature should be recorded. The value of measured resistance should be converted to the value of temperature at which factory test results are taken. Temperature corrected value of resistance should be comparable to the factory value.

6.5.2

50 OPERATION TESTS

6.6

CHECKS/ TESTS APPLICABLE FOR SURGE ARRESTERS

6.6.1

MEASUREMENT OF THIRD HARMONIC RESISTIVE CURRENT FOR SURGE ARRESTERS Testing Procedure a. b. c. d. e. f.

Make the connections as per the diagram given below (Fig.18) The kit should be properly earthed. Clamp On type CT should be placed above the surge monitor to pick up the total leakage current. Carryout the measurements as per standard procedure supplied by the test kit manufacturer. Note down the system voltage and ambient temperature along with the test current value. Avoid measurement during monsoon.

Field probes for harmonics in the system

Adapter

Test Kit

Figure- 18 Typical arrangement for THRCM Test Pre-Commissioning Procedures For Switchyard Equipments

55

Doc No. D-2-01-03-01-03

EVALUATION OF TEST RESULTS A.

ZnO Surge Arrester continuously conducts a small leakage current (Fig.19). The resistive component of this leakage current may increase with time due to different stresses causing ageing and finally cause arrester failure.

B.

If Harmonics are present in the system voltage, it affects the value of measured third harmonic current. Compensating device provided to be used to nullify the effect. The value of Third Harmonic Resistive current shall be less than 30 µA HV side

Non-linear resistor

Capacitance

Figure-19 Arrester equivalent circuit 6.7 6.7.1

CHECKS/ TESTS FOR OTHER AREAS/ EQUIPMENTS EARTH RESISTANCE MEASUREMENT Normally Earth tester is used for measuring (a)

Soil resistivity

(b)

Earth resistance

a.

Prior to the testing of soil resistivity and earth resistance the operation manual of the testing instrument available at site may be referred for procedures to be adopted for measurement of soil resistivity and earth resistance. A typical earth tester has 4 terminals. C1, P1, C2, P2 and 4 similar electrodes are driven in the ground at equal distances and connected to the instruments in the order of C1, P1 and P2, C2. Then the handle is rotated or button is pressed and the reading of the resistance is read on the scale of the instrument. If R is the resistance measured then Specific Resistivity = 2 a R Where 'a' is the distance between the electrode And R is the resistance in ohms measured on the earth tester.

b.

56

In order to measure earth resistance of the electrode of the substation, it could be connected to C1 and the value of R could be read in the scale with the rotation of the handle of the Insulation tester. This will give the earth resistance. The value as far as possible should be around 1 ohm. To improve the value, water should be spread at the earth pit.


Doc No. D-2-01-03-01-03

6.7.2

SECONDARY CURRENT INJECTION TEST SETS The primary test is essential when commissioning and new installation as a test the whole protection system and will detect current transformers connected with incorrect polarity or relays that have been set in the wrong sequence in differential system. Secondary current injection sets are very useful for conducting these tests. The standard secondary current injection test equipment consists of a 1/5 A current injection set, separate wave form filter unit and a digital counter. The equipment is designed in a portable kit for on site testing of protecting devices, circuit breakers, trip coils, motor overloads, and similar apparatus. The filter unit should be used when testing saturating core type relays to ensure that the test current has a substantially sinusoidal waveform. The typical test setup is shown in fig. 20. Details of the testing will be elaborated in the relay testing.

INSULATING TEST PLUGS P1

P1

P1

S1

INJECT CURRENT HERE

S2 A1 A2

LOAD

Figure - 20


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Doc No. D-2-01-03-01-03

6.7.3

CONTACT TIGHTNESS TEST OF BAY CONTACTS: a.

Isolate the Bay from Bus –Side and line side as shown in Fig.-21.

b.

Ensure that all the secondary cores are connected or short if not in use.

c.

Inject the Current at Point 1 (200A) from primary injection kit (w r t earth) and return current via earth point at 2 as shown in Fig.-21.

d.

Check that we are able to inject current at point 1 and measure the current at point 2.

e.

Injection of current is the indication of contact tightness.

f.

Repeat the procedure for point 1 & 3

g.

Repeat the procedure for point 1 & 4

Note: Above tests can be aborted if individual contact resistances are within satisfactory limit and physical phase checking is satisfactory.

POINT 1

POINT 2 LINE

CB

CB

LINE

POINT 4

POINT 3

Figure-21 : Primary injection test to check contact tightness of Bay/ feeders

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Doc No. D-2-01-03-01-03

CHECKS/TESTS FOR BUS BAR PROTECTION Types of bus bar protection a) High impedance b) Low impedance 7.1

High Impedance protection The High-impedance protection scheme, is a good solution for single busbar arrangements, 1 ½ breaker systems or ring Busbars, provided that appropriate dedicated CT cores are available for this use alone. Sensitive, stable and fast protection for single busbar arrangements and 1 ½ breaker systems. Eg: RADHA (ABB), FAC 34 (EE), PBDCB (EE), PBLSB (EE)

7.1.1

Types of High impedance protection schemes Two main protections with CT supervision feature Main & check zone scheme a)

Two main protections

Generally used where direct measurement is possible without switching of the CT circuits Trip command will be issued on operation of any one of the main protection. b)

Main & check zone scheme

Have highest degree of security in the form of check zone, generally used where CT switching is required through auxiliary contacts of isolator (like 220kV DMT scheme) For a double busbar arrangement, two different high impedance units are required. In this case, the current must be switched between the two different measuring units by connecting auxiliary switches to the busbar isolator contacts. In some cases the auxiliary switches did not operate correctly. This caused the busbar Protection to trip the busbar. For this reason, a safety precaution was introduced: An overall Check-Zone unit, fed from individual CT cores. This overall scheme does not include any switching of CT and therefore is more secure. The TRIP command is only issued when both a discriminating and check-zone system Operates. The relay coil will be designed as voltage measuring device consuming negligible current. Vf = If (Rct+2.Rl) Vk=2Vf Paralleling CT current should be done at CT marshalling boxes.


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Doc No. D-2-01-03-01-03

7.1.2

CT requirements for High impedance protection system Ø Knee point voltage requirement of the CT will be high Ø CT core shall be dedicated to the High-impedance Busbar Protection Scheme (i.e. cannot be shared with other protection relays) Ø CT Must have identical turns-ratio (CT Ratio) (Aux.CT for ratio corrections not acceptable) Ø Shall have a low resistance of the secondary windings Ø Shall have a minimum knee-point voltage of approx. 300-500V. Ø Should have a low magnetising current (few milliamps)

7.1.3

Supervision of the CT circuits Any interruption of CT currents up to the point of parallel connection can cause instability during external faults even though their degree of unbalance is with in the limits during normal operation. Hence supervision scheme for CT wire are required. Supervision relay should be provided across each phase for each zone. It will block the current passing through the differential relay by shorting the CT terminals General setting of the CT supervision relay is 10% of the lowest circuit rating. Calculation of typical settings for bus bar differential protection CT ratio:

: 2000/1

CT resistance:

: 10 Ohms

Max. bus fault MVA

: 10000 MVA

Max. fault current

: 10000x106/1.732*400000 =14434 A

Fault current in secondary

: 7.217A

Voltage setting of the relay

: Vf or VS = If (Rct+2RL)

Lead resistance of 1000m, 2.5sq.mm copper wire is 7.28 ohms Assume 500m of lead length Vs= 7.217* (10+2*7.28/2) =124.7V Nearest available setting can be adopted for the relay 7.2

Low Impedance bus bar scheme The most suitable protection scheme for Double and multiple busbar Systems (with or without transfer bus) with feeders being switched between sections of the busbar, which operates with full selectivity for all possible busbar configurations.

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Doc No. D-2-01-03-01-03

Free of any need for matched CT characteristic or ratios, low leakage reactance or resistance. Other protective relays can be included in the same circuit. Stable for infinite fault level. Insensitive to CT saturation. All the CT wiring will be routed to relay either directly or through aux. relay. Eg: RADSS (ABB), MBCZ (EE) 7.3.

Primary injection and bus bar differential stability test (New Substation)

Bus - I Bus - III T Bay A

Bay B

T - Primary current injection text kit 1.

Take one of the bays (A) as the reference

2.

Select other bay (B) for testing the differential stability. Inhibit the tripping of the breaker in bay B from control room due to operation of distance or over current protection caused by primary current injection, if the earthing has been made after the breaker by using earth switch.

3.

Earth the bus bar after CT using local earth or nearby earth switch on bay B to provide return path for the current.

4.

Ensure bus bar is earthed only at bay B

5.

Inject primary current using primary current injection test kit across one phase (e.g.R Phase) and ground; don't use other phase as return path for the current.

6.

Measure the current at both CT marshalling boxes and voltage across differential relay terminals incase of high impedance differential protection.

7.

Measure currents before and after aux. CTs and at relay terminals, incase of low impedance differential protection is being installed.


61

Doc No. D-2-01-03-01-03

7.4.

8.

The measured spill voltage/current at relay terminals should not be more than 2%.

9.

If the spill voltage/current is more (almost twice the CT secondary current) at the relay terminals, stop injecting the primary current and then reverse the secondary terminals of CT at bay B.

10.

Start injecting primary current and measure the current at both CT marshalling boxes and at the relay terminals at control room and observe the spill current/ voltage magnitude less than 2%.

11.

Stop injecting primary current and then create in-zone fault on primary side (by providing earthing between the two CTs) and start injecting primary current and Measures the current at both CT marshalling boxes and at the relay terminals at control room and observe the spill current/ voltage of considerable magnitude corresponding to the injected primary current. (a pictorial example is attached herewith at Annexure)

12.

After ensuring the above stop injecting the current. The CT connection should be as per polarity thus proved.

13.

Repeat the test for other two phases.

14.

Repeat the same procedure for other bays of the same bus bar by taking adjacent bus bar stability checked bay as the reference bay in order to inject max. possible current in the primary using primary injection test kit.

15.

Repeat the above procedure for other bus bars also.

16.

Above said procedure shall be carried out between Phase-Phase (R-Y &Y-B) by injecting in one phase and joining with other phase for using it as return path instead of earth return for one set of CTs (Two bays).

Primary injection and bus bar differential stability test (Bay Extension in the old substation):

Bus - I Bus - III Bay A

Bay B

T

Newly adding diameter T- Primary current injection test kit

62


Doc No. D-2-01-03-01-03

1.

Arrange the shutdown of the bus barunder test

2.

Consider one of the existing bays (A) as the reference

3.

Short the CT cores used for the other protections (like LBB, distance or differential or O/C or metering, etc), at CT MB itself, no CT core shall be in open condition.

4.

Select one of new bays (B) for testing the differential stability and inhibit the tripping of the breaker from control room due to operation of distance or over current caused by primary current injection.

5.

Earth the bus bar after CT using local earth or nearby earth switch on bay B.

6.

Ensure bus bar is earthed only at bay B

7.

Inject primary current using primary current injection testing kit across one phase (eg.R Phase) and ground; don't use other phase as return path for the current.

8.

Measure the current at both CT marshalling boxes and voltage across differential relay terminals incase of high impedance differential protection.

9.

Measure currents before and after aux. CTs and at relay terminals, incase of low impedance differential protection is being installed.

10.

The measured spill voltage/current at relay terminals should not be more than 2%.

11.

If the spill voltage/current is more (almost twice the CT secondary current) at the relay terminals, stop injecting the primary current and then reverse the secondary terminals of CT at bay B.

12.

Start injecting primary current and measure the current at both CT marshalling boxes and at the relay terminals at control room and observe the spill current/voltage magnitude less than 2%.

13.

Stop injecting primary current and then create in-zone fault on primary side (by providing earthing between the two CTs) and start injecting primary current and measure the current at both CT marshalling boxes and at the relay terminals at control room and observe the spill current/ voltage of considerable magnitude corresponding to the injected primary current. (a pictorial example is attached herewith at Annexure)

14.

After ensuring the above stop injecting the current. The CT connection should be as per polarity thus proved.

15.


16.

Repeat the same procedure for other bays of the same bus bar by taking adjacent bay (whose stability check completed) as the reference in order to inject max. possible current in the primary using primary injection test kit.

17.

Repeat the above procedure for other bus bars also.

18.

Restore the system to normal conditions.


63

Doc No. D-2-01-03-01-03

7.5

Scheme Checking of bus bar protection & DC trip logic. (New substation & Bay extension)

7.5.1

Two Main protection philosophy 1. 2. 3. 4. 5. 6. 7.

8. 9. 7.5.2

64

Test the relay by secondary injection. Check the tripping of the corresponding breakers and non tripping of other bus breakers and tie breakers. Check initiation of LBB relays of the breakers corresponding to particular bus. Check blocking of the bus bar protection on operation of CT supervision relay. Ensure that operation of CT supervision relay should not initiate bus bar tripping. Check initiation of bus bar tripping by operation of corresponding breaker LBB relays.(Back Trip feature) a. Check the direct tripping scheme on operation of bus bar protection (only if tie breaker is in open condition) b. Direct trip signal should not go on operation of Bus bar protection if the Tie CB is in close condition. Test CT supervision relays and ensure for triggering control panel annunciation and event logger triggering as per approved scheme. Check bus bar IN/OUT switch for correctness of wiring as per the drawing.

Main and Check zone philosophy 1. Test the both main and check zone relays by secondary injection. 2. Ensure bus bar should not initiate tripping for operation of either main or check zone alone. 3. For checking the tripping scheme, bypass the check zone contact. 4. Check the tripping of the corresponding breakers and non tripping of other bus breakers and tie breakers. 5. Check initiation of LBB relays of the breakers corresponding to particular bus. 6. Check blocking of the bus bar protection on operation of CT supervision relay. 7. Ensure operation of CT supervision relay should not initiate bus bar tripping. 8. Check initiation of bus bar tripping by operation of corresponding breaker LBB relays.(Back Trip feature) 9. a. Check the direct tripping scheme on operation of bus bar protection (only if tie breaker is in open condition) b. Direct trip signal should not go on operation of Bus bar protection if the Tie CB is in close condition. 10. Test CT supervision relays and ensure for triggering control panel annunciation and event logger triggering as per approved scheme. 11. Check bus bar IN/OUT switch for correctness of wiring as per the drawing. 12. Repeat the above for check zone and CT supervision schemes.


Doc No. D-2-01-03-01-03

7.6

AMP Testing of bus bar protection and scheme 1.

Arrange bus bar shutdown for off line testing. Preferably the bus bar isolation should done through bus bar protection trip relay.

2.

Insert the test block after shorting the incoming current terminals for on line testing.

3.

Test the relays.

4.

For off line testing:

5.

i.

Check tripping scheme of bus bar (2 main/ main and check scheme), in case of main and check scheme, operation of one relay should not initiate bus bar trip.

ii.

Check initiation from LBB of corresponding bays of bus bar

iii.

Check initiation of LBB of corresponding bays of bus bar

iv.

Check annunciations and DR triggering as per the drawings

After completion of the above checks, normalise the connections and take bus bar into service.


65

Doc No. D-2-01-03-01-03

7.7

Double main transfer scheme (400kV/220kV): For the double main transfer scheme, bus bar protection shall preferably be Main and check zone scheme because of dependency on CT switching between BUS-I & II bus bar protections.

7.7.1

Primary injection and bus bar differential stability test (New Substation):

BUS-I BUS-II A1

Bay A

A2

A3

B1

B2

C1

C2

X2

X1

Bay B

B4 TE

X

T2

Bay T

Bay C

B3

A4

T1

T3 TRANSFER BUS

TE – Testing Equipment X – Temporary Earthing point

66

1.

Take one of the bays (A) as the reference

2.

Select other bay (B) for testing the differential stability. Inhibit the tripping of the breakers in bay A and B from control room due to operation of distance or over current protection caused by primary current injection.

3.

Earth the bus bar after CT at X using earth rods on bay B.

4.

Preferably connect the primary injection testing kit to the CT terminal pad of reference bay (A) after opening the jumper from line side.

5.

Ensure that bus or line connected to bay B shall not be earthed other than at X.

6.

Close the isolators A1 in bay A, B1 in bay B and Ensure that corresponding CT switching relays operated for checking the bus bar differential stability of BUS-1.

7.

Close isolator A3 and breaker in bay A and isolator B3 and breaker in bay B.

8.

Measure the resistance of the CT cores (used for main and check zone) towards CT in the CT switching cubicle and it shall be equal to the sum of resistance of the CT core and lead resistance. If the resistance towards CT core is more, then check the CT circuit and corresponding CT switching relay. Pre-Commissioning Procedures For Switchyard Equipments

Doc No. D-2-01-03-01-03

9

Inject primary current using primary injection testing kit from bay A.

10.

Measure the current at both CT marshalling boxes (both cores used for main and check zone) and relay terminals in the control room in case of low impedance protection or measure voltage across cores in CT MB and differential relay terminals incase of high impedance differential protection.

11.

The measured spill voltage/current at relay terminals shall be very less compared to the primary current/corresponding voltage (around 2%).

12.

If Spill current/voltage is more (almost twice the CT secondary current) at the relay terminals. a.

Stop injecting the primary current and Check CT paralleling connections after the CT switching relay. If every thing is correct then reverse the secondary terminals of CT at bay 'B'.

b.

Start injecting primary current and Measures the current/voltage at both CT marshalling boxes and relay terminals at control room and observe the spill current/ voltage magnitude shall be very less compared to the set value (around 2%).

13.

Stop injecting primary current and then create in-zone fault in primary side (by providing earthing between two CTs).

14.

Start injecting primary current and Measures the current at both CT marshalling boxes (both cores used for main and check zone) and at the relay terminals at control room and observe the spill current/ voltage of considerable magnitude corresponding to the injected primary current.

15.

After ensuring the above stop injecting the current and normalize the system.

16.

Open isolators A1 on bay A& isolator B1 on bay B and ensure that corresponding CT switching relay got resetted.

17.

Close isolators A2 in bay A, B2 in bay B for connecting the feeder to bus-2 and ensure the operation of corresponding CT switching relay for checking the bus bar differential stability of BUS-2.

18.

Repeat the above sequence from 9 to 16

19.

Open isolators A2 on bay A& isolator B2 on bay B and ensure that corresponding CT switching relays got resetted.

20.


21.

Above said procedure shall be carried out between Phase-Phase (R-Y &Y-B) by injecting in one phase and joining with other phase for using it as return path instead of earth return for one set of CTs (Two bays).

22.

Repeat the same procedure for other bays including transfer bus coupler bay w.r.t Bus-I & II.


67

Doc No. D-2-01-03-01-03

7.7.2

7.7.3

Checking of differential protection stability w.r.t bus coupler: 1.

Take one of the bay A as the reference bay

2.

Close isolator A1 in bay A to check differential stability of the bus coupler w.r.t Bus-1.

3.

Close isolator C1 and breaker in bus coupler bay C and earth at X1 in bay C.

4.

Adopt the same procedure as explained above for stability testing of normal bays.

5.

Open breaker & isolators A1 in bay A and Open breaker & isolator C1 on bay C,

6.

Close isolator A2 & breaker in bay A and isolator C2 & breaker on bay C to check differential stability of bus coupler CT w.r.t Bus - 2.

7.

Earth bay C at X2.

8.

Adopt the same procedure as explained above for stability testing of normal bays.

9.

Open the breaker and isolator in bay A & bay C and open earthing on bay C and normalize the system.

Checking of differential protection stability w.r.t Transfer bus:

BUS-I BUS-II A1

A2

B1

B2

C1

C2

T1

T2 Bay T

Bay A

Bay B

A3

A4

E

B3

Bay C

B4

TE

T3 TRANSFER BUS

68

1.

Before carrying out this test, ensure that differential protection stability with respect to Bus –I & Bus-II has been carried out on all bays including transfer bus coupler bay.

2.

For checking the differential protection stability w.r.t to transfer bus, take one of the bays as reference bay and inject current from transfer bus coupler bay CT.

3.

Close isolator T3 and breaker in transfer bus coupler bay T.

4.

Close isolator A4 to check stability w.r.t transfer bus and ensure the operation corresponding CT switching relay.

5.

Keep the normal/transfer switch of bay A in transfer mode.


Doc No. D-2-01-03-01-03

6.

Measure the resistance of the CT cores towards CT in the CT switching cubicle and it shall be equal to the resistance of the CT core and lead resistance. If the resistance towards CT core is more, then check the CT circuit and corresponding CT switching relay.

7.

Inject primary current using primary injection testing kit from bay T.

8.

Measure the current at both CT marshalling boxes and relay terminals in the control room in case of low impedance protection or measure voltage across cores in CT MB and differential relay terminals incase of high impedance differential protection.

9.


10.


Stop injecting the primary current and Check CT paralleling connections after the CT switching relay. If every thing is correct then reverse the secondary terminals of CT at bay 'T' only while testing first bay.

b.


11.

Stop injecting primary current and then create in-zone fault in primary side (by providing earthing between two CTs)

12.

Start injecting primary current and Measures the current at both CT marshalling boxes and at the relay terminals at control room and observe the spill current/ voltage of considerable magnitude corresponding to the injected primary current.

13.


14.

Open isolators and earthing which are closed for testing and keep N/T switches in normal position.

15.


16.

Repeat the above procedure for other bays to ensure the operation of CT switch relay for transfer bus.


69

Doc No. D-2-01-03-01-03

7.7.4

Primary injection and bus bar differential stability test for Bus-I (Bay extension in existing Substation) BUS-I BUS- II A1

A2

B1

B2

C1

B3 Bay B

A3 Bay A A4

B4 TE

C2

T1

T2

Bay C

T3

E

TRANSFER BUS New bay

70

1.

Arrange the shutdown of the one of the existing feeder or take a bay which is already in out of service as reference bay (A).

2.

Arrange shutdown of the bus bar (Bus-I).

3.

Close the isolator of new bay B (B1) and ensure the operation of corresponding CT switching relay.

4.


5.

Close the isolator B3 and breaker in bay B and isolators A1, A3 and breaker in bay A for connecting the CTs to Bus-I.

6.

Inject primary current using primary injection testing kit from bay A.

7.

Measure the current at both CT marshalling boxes (both cores used for main and check zone) and relay terminals in the control room in case of low impedance protection or measure voltage across cores in CT MB and differential relay terminals incase of high impedance differential protection.

8.


9.

If Spill current/voltage is more (almost twice the CT secondary current) at the relay terminals:


Doc No. D-2-01-03-01-03

7.7.5

a.

Stop injecting the primary current and check CT paralleling connections after the CT switching relay. If every thing is correct then reverse the secondary terminals of CT at bay 'B'.

b.

Start injecting primary current and Measures the current/voltage at both CT marshalling boxes and relay terminals at control room and observe the spill current/ voltage magnitude shall be very less compared to the primary current/corresponding voltage (around 2%).

10.

Stop injecting primary current and then create in-zone fault in primary side (by providing earthing between two Cts.

11.

Start injecting primary current and Measures the current at both CT marshalling boxes (both cores used for main and check zone) and at the relay terminals at control room and observe the spill current/ voltage of considerable magnitude corresponding to the injected primary current.

12.


13.

Open the breaker and isolator A1 in bay A and breaker and isolator B1 in bay B.

14.

Repeat the above procedure for other phases.

15.

Repeat the testing of the other newly adding bays (if any) taking this stability tested new bay (B) as the reference bay to avoid outage of old reference bay A for longer periods.

16.

Repeat the above procedure of stability testing for new bay w.r.t. Bus-II by selecting of appropriate section (i.e. isolators A2 & B2) with Bus-II shutdown.

Primary injection and bus bar differential stability test w.r.t to transfer bus (Bay extension in existing Substation): BUS-I BUS- II A1

A2

B1

C1

B3 Bay B

A3 Bay A A4

B2

B4

C2

T1

Bay C

T2

TE

T3

E

TRANSFER BUS New bay Pre-Commissioning Procedures For Switchyard Equipments

TE - Testing equipment 71

Doc No. D-2-01-03-01-03

72

1.

Arrange shutdown of transfer bus.

2.

Take transfer bus T as reference bus.

3.

Close isolator B4 and keep N/T switch in transfer position and ensure the operation of corresponding CT switching relay.

4.


5.

Close isolator T3 and breaker in bay T.

6.

Inject primary current using primary injection testing kit from bay T.

7.

Measure the current at both CT marshalling boxes and relay terminals in the control room in case of low impedance protection or measure voltage across cores in CT MB and differential relay terminals incase of high impedance differential protection.

8.

The measured spill voltage/current at relay terminals shall be very less compared to the set value (around 2%).

9.


Stop injecting the primary current and Check CT paralleling connections after the CT switching relay.

b.


10.

Stop injecting primary current and then create in-zone fault in primary side (by providing earthing between two CTs.

11.

Start injecting primary current and Measures the current at both CT marshalling boxes and at the relay terminals at control room and observe the spill current/ voltage of considerable magnitude corresponding to the injected primary current.

12.


13.

Start injecting primary current and measure the current/voltage at relay terminals and ensure that its magnitude is very less compared to the primary current.

14.

Open isolators and earthing which are closed for testing and keep N/T switches in normal position.

15.



Doc No. D-2-01-03-01-03

7.8

Scheme checking of bus bar protection & DC trip logic. (New substation & Bay extension)

7.8.1

Two Main protection philosophy

7.8.2

1.

Test the relay by secondary injection.

2.

Check the tripping of the corresponding selected breakers and bus coupler breaker (in case of Bus-I & Bus-II only) and non tripping of other breakers.

3.

Check initiation of LBB relays of the selected breakers corresponding to particular bus.

4.

Check blocking of the bus bar protection on operation of CT supervision relay.

5.

Ensure that operation of CT supervision relay should not initiate bus bar tripping.

6.

Check initiation of bus bar tripping by operation of corresponding breaker LBB relays.(Back Trip feature)

7.

Check the direct tripping scheme on operation of bus bar protection.

8.

Test CT supervision relays and ensure for triggering control panel annunciation and event logger triggering as per approved scheme.

9.

Check bus bar IN/OUT switch for correctness of wiring as per the drawing.

Main and Check zone philosophy 1.

Test the both main (i.e. Bus-I, Bus-II and Transfer Bus) and check zone relays by secondary injection.

2.

Ensure bus bar should not initiate tripping for operation of either main or check zone alone.

3.

For checking the tripping scheme, bypass the check zone contact.

4.

Check the tripping of the corresponding selected breakers and bus coupler breaker (in case of Bus-I & Bus-II only) and non tripping of other breakers.

5.

Check initiation of LBB relays of the breakers corresponding to particular bus.

6.

Check blocking of the bus bar protection on operation of CT supervision relay.

7.

Ensure operation of CT supervision relay should not initiate bus bar tripping.

8.

Check initiation of bus bar tripping by operation of corresponding breaker LBB relays.(Back Trip feature)

9.

Check the direct tripping scheme on operation of bus bar protection.

10.

Test CT supervision relays and ensure for triggering control panel annunciation and event logger triggering as per approved scheme.

11.

Check bus bar IN/OUT switch for correctness of wiring as per the drawing.

12.

Repeat the above for check zone and CT supervision schemes.


73

Doc No. D-2-01-03-01-03

7.9

74

AMP testing of bus bar protection and scheme 1.

Arrange bus bar shutdown for off line testing and scheme checking.

2.

While switching all the loads from one bus to other bus observe the operation and resetting of corresponding CT switching relays in accordance to the operation of isolators.

3.

CT switching discrepancy alarm shall not appear in the control panel.

4.

Check tripping scheme of bus bar ( 2 Main/ Main and check scheme), in case of main and check scheme, operation of one relay should not initiate bus bar trip.

5.

Check annunciations and DR triggering as per the drawings

6.

After completion of the above checks, normalise the connections and take bus bar into service.

7.

Insert the test block after shorting the incoming current terminals for on line testing.

8.

Test the relays.


Doc No. D-2-01-03-01-03

PRE-COMMISSIONING FORMATS FOR TRANSFORMER I.

GENERAL DETAILS DETAILS

Region:

Sub-Station:

LOA No. :

Make:

Sr. No.:

Type:

Year of Manufacture:

Rating:

Voltage Ratio :

Cooling Type:

Type of Neutral Grounding:

Oil Make:

Oil type:

Oil quantity:

Date of Receipt at site:

Date of Starting of Erection:

Date of Completion of Erection and Oil filling:

Date of energisation( After commissioning)

II.

CHECK LIST OF ELECTRICAL TESTS CARRIED OUT FOR TRANSFORMER

SL.N O

a b c d e f g h i j k l m n

NAME OF TEST

PERFORMED (YES/NO)

TEST RESULTS (OK/ NOT OK)

Insulation Resistance Measurement Vector Group Test & Polarity Check Short Circuit Impedance Test Magnetic Balance Test Floating Neutral Voltage Measurement Magnetisation Current Test Voltage Ratio Test Insulation Resistance Measurements Of Bushing CTs Continuity Test Of Bushing CTs Secondary Winding Resistance Of Bushing CTs Polarity Test Of Bushing CTs Current Ratio Test Magnetizing Curves Performance Contact Resistance Measurement

No. CF/ICT/01/ R-3 DATED 01/04/2011

Transformer

75

Doc No. D-2-01-03-01-03

SL.N O

o p q r s t

NAME OF TEST

PERFORMED (YES/NO)


Tan Delta & Capacitance Measurement Of Bushing Tan Delta & Capacitance Measurement Of Windings Protection And Alarm Tests Stability Test Of Differential And Ref Protection Frequency Response Analysis Measurement of Winding Resistance

Signature:

Signature:

Signature:

Signature:

Name:

Name:

Name:

Name:

Desgn.:

Desgn.:

Desgn.:

Desgn.:

Organization: (Supplier Representative) (Wherever Applicable)

(Erection Agency)

(POWERGRID Site I/C)

(POWERGRID Commg. Team) Members:

76 Transformer

No. CF/ICT/01/ R-3 DATED 01/04/2011

Doc No. D-2-01-03-01-03

III.

CHECKS AFTER RECEIPT OF TRANSFORMER AT SITE:

A) N2 PRESSURE & DEW POINT RECORD N2 PRESSURE

DEW POINT

*REMARKS

During dispatch at factory After receipt at site Storage at site before commissioning * Please

write 'NIL' in case of No Remarks

NOTE: N2 pressure and dew point should be within permissible range as per graph provided by manufacturer and also given in os doc no d-2-03-xx-01-01 rev-01. During storage at site, dew point has to be measured whenever any drop in n2 pressure is observed. During storage at site before commissioning, n2 pressure has to be measured daily and record to be maintained in a separate sheet. Refer graph 2.1.3 fig.1

B) IMPACT RECORDER ANALYSIS STATUS

Received in healthy condition at site Analysis report received from manufacturer before charging

Yes

No

Yes

No

BRIEF ANALYSIS

Note: Impact Recorder should be detached from the Transformer preferably when the main unit has been placed on its foundation.

*Permissible limit for maximum shock is ±3G for any axis. C) CORE INSULATION TEST APPLY 1 kV DC BETWEEN CL & CC + G

INSULATION VALUE

Between CC-G Between CL-G Between CC-CL Note: Shorting link between CC, CL & G to be removed and IR value to be taken between CC-G, CL-G & CCCL (Recommended value > 10 M? )

D) INTERNAL INSPECTION INTERNAL INSPECTION

STATUS YES NO

Details photographs of all visible parts /components are taken during internal inspection and enclosed.(refer procedure2.1.6) Any abnormality observed during internal inspection Matter referred to manufacturer, CC-ENGG and CC-OS Details of abnormalities notice if any: No. CF/ICT/01/ R-3 DATED 01/04/2011

Transformer

77

Doc No. D-2-01-03-01-03

CHECKS /PRECAUTIONS DURING ERECTION :

IV.

a. Active part of transformer should be minimum exposed to atmosphere b. Use of dry air generator / dry air cylinders, during exposure of active part of transformer to atmosphere.

Yes

c. While entering in transformer tank, check availability of proper Oxygen

Yes

No

Remarks

d. Transformer kept sealed with N2 in between different erection activities

Yes

No

Remarks

No

Remarks

PRE-COMMISSIONING CHECKS:

V.

STATUS

SL. NO.

1 2 3 4

5

6

7 8 9

DESCRIPTION OF ACTIVITY YES

ICT and its Auxiliaries are free from visible defects on physical Inspection All fittings as per out line General Arrangement Drawing Check Main Tank has been provided with double earthing Check neutral is grounded through separate connections. Ensure metallic requirements as per specification (e.g. Cu) in earthing strips used Check that Marshalling Box, T/C Driving Gear, Diverter, Radiator Bank Pump & Fan Motor etc. has been earthed All nuts and bolts are tightened correctly as per specified torque (as per manufacturers recommendation) Check tightness of Terminal Connectors Check leveling of Transformer and its accessories

11

Erection Completion Certificate along with list of outstanding activities reviewed Any Paint removed / scratched in transit has been touched up Bushings are clean and free from physical damages

12

Oil level is correct on all Bushings

13

Check Hermitically sealing is intact in all Bushings

14

Check oil leakage through any Joints / Valves etc.

15

Check oil drain valves are properly closed and locked

16

Check oil level in Main / OLTC Conservator tank

10

NO

REMARK DEFICIENCIE S, IF ANY

78 Transformer

No. CF/ICT/01/ R-3 DATED 01/04/2011

Doc No. D-2-01-03-01-03

17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35

36 37 38

39 40 41

Check oil level at conservator matches with oil temperature of transformer Check Gear box oil level in OLTC Check OTI and WTI pockets and replenish the oil, if required Check all valves for their opening & closing sequence Check the colour of the breather silica gel (blue when dry) Check availability of oil in the breather cup Check all rollers are locked and tack welded with rails (wherever applicable) Check busing test tap is grounded Check no debris, loose T & P and oil strains on and around the Transformer Check door seals of Marshalling Box is intact and all cable gland plates unused holes are sealed Check that pressure relief valve is correctly mounted Ensure unused secondary cores of Bushing CT’s, if any, has been shorted Check CT star point has been formed properly and grounded at one end only as per scheme Check that permanent and adequate lighting arrangements are ready Check that labeling and identification is permanent and satisfactory Check that Buchholz Relay is correctly mounted with arrow pointing towards conservator Check cables are properly fixed and ensure cable entry at the bottom Ensure all Power and Control cable Terminals are tightened Check all cables and Ferrules are provided with Number as per Cable Schedule (Cross Ferruling to be checked) Check that all cables are correctly glanded Check external cabling from Junction Box to Relay / Control Panel completed Check that air has been released from the Radiators and their headers/OLTC Buchholz relay/Main tank/tank/Bushing turrets etc Check Fire Protection System & Emulsifier systems is adequate & ready Check that CC-CL & G are shorted Check that all radiator bank valves on top and bottom headers are open

No. CF/ICT/01/ R-3 DATED 01/04/2011

Transformer

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Doc No. D-2-01-03-01-03

42

Change over operation of ac supply from source- I to source-II checked Check the flanges of bushing & oltc for any crack after fixing Calibration of OTI & WTI performed as per procedure Check various interlocks provided with Fire Fighting as per the schematic Ref. Drg. No.___________________

43 44 45

VI.

Description of Interlocks

Checked

MEASUREMENT OF EARTH RESISTANCE OF ELECTRODE LOCATION

VALUE

With Grid (Earth Pit -1) Without Grid (Earth Pit -1) (Neutral Earth ) With Grid (Earth Pit -2) Without Grid (Earth Pit -2) (Neutral Earth) *Permissible limit with grid < 1 ohm VII.

DETAILS OF RELAYS/ CONTACTORS USED: SCHEMATIC DRAWING NO. CIRCUIT REFERENCE

VIII.

MAKE

SERIAL NO.

TYPE

NO+NC

EVACUATING AND OIL FILLING

a) Before filling oil, each drum has been physically checked for free moisture and appearance

Yes

No

b) Details of oil filter machine Make _____________________

DESCRIPTION OF WORKS

SL.NO

1 2 3 4

Capacity________________________ REMARKS / READING

Changing of Lubricating oil of vacuum pump Cleaning of Filter packs Flushing of whole filter machine with fresh oil Vacuum obtained without load (milli bar)

c) Vacuum pump for evacuation of transformer DESCRIPTION OF WORKS

SL.NO

1 2 3 4

REMARKS / READING

Changing of Lubricating oil of vacuum pump Vacuum obtained without load (milli bar) Diameter of vacuum hose (50 mm) Employ of Dry ice chamber

80 Transformer

No. CF/ICT/01/ R-3 DATED 01/04/2011

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d) Oil storage tank Capacity_____________________

Quantity_________________________


SL.NO

1 2 3 4

REMARKS / READING

Silica gel breather provided in the tank Any opening left uncovered Inside painted or not Cleanliness of inside of pipes/ hoses to the storage tank

e) Exposure during erection DESCRIPTION OF WORKS

SL.NO

1 2 3 4 5 6 7

REMARKS / READING

First day exposure ( in hrs) Second day exposure ( in hrs) Third Day exposure ( in hrs) N2 pressure applied after each days erection work ( in PSI) Ambient Temperature (in degC) Average Relative Humidity Weather Condition

Rainy / Stormy / Cloudy / Sunny

f) N2 i.sealing in case of delay in oil filling DESCRIPTION OF WORKS

SL.NO

1 2 3 4 ii. Sl.No

1 2 3 4 5

6 7

REMARKS / READING

No. of Cylinders used for displacing the air inside the tank N2 admitted from bottom valve Valve at diametrically opposite end at top kept open No. of Cylinders used for building up 2 PSI Schedule for Vacuum & Tightness Test INSPECTION ACTIONS

DATE

TIME

REMARKS / READING

Starting of evacuation on complete unit Stopping of evacuation below the pressure of 0.3 kPa (3 mbar) Pressure P1 in kPa after 1 hour of stopping evacuation Pressure P2 in kPa after half an hour of reading pressure P1 Leakage = (P2-P1) x V , V=Oil quantity in Cu mtr *If leakage >3.6, continue evacuating If leakage < 3.6Similar action may be carried out for 2 to3 times for confirmation. Start of Vacuum after N2 pressure reaching below 0.13kPa(1 torr) Break of vacuum * Vacuum to be kept for 12 hrs Up to 145 KV, 24 hrs for 145 to 220kV and 36 hrs for 420 kV and above

No. CF/ICT/01/ R-3 DATED 01/04/2011

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iii.

Schedule for Oil filling and Settling

Sl.N o

INSPECTION ACTIONS

1

DAT E

REMARKS / READING

Oil Filling in Main Tank Oil filling in Conservator tank

2 3 4

Oil filling in diverter switch Start of oil settling

5

End of oil settling * Minimum settling time to be given 12 hrs for 145 KV ,48 hrs for 145 to 420kV and 120 hrs for above 420 kV .

iv.

TIM E

Record of drying out process (if carried out) Drying out started on date: Ambient temp:

Time:

Hourly reading to be taken

DATE

VACUUM READING IN FILTRATION MACHINE

TIME

VACUUM READING IN TRANSFORMER TANK

OTI OF TANK

CONDENSATE COLLECTED TOTAL / RATE

REMARKS & SIGN OF MTC ENGINEER

Record of filtration and Dry out shall be kept in a register and shall be made a part of the Precommissioning document. IX.

INSULATION RESISTANCE MEASUREMENT

a)

Insulation Resistance Measurement of Cable and others (Using 500 Volt Megger) Make & Sl. No of testing kit _____________________ Date of last calibration of kit _____________________ Ambient temp in º C

SL. NO.

A B

C

_____________________

DESCRIPTION

STATUS YES

NO

REMARKS, IF ANY

Control wiring Tap changer a) Motor b) Control Cooling System a) Motor Fan b) Motor Pump c) Control wiring

* Permissible limit of IR value should be > 50 M ? 82 Transformer

No. CF/ICT/01/ R-3 DATED 01/04/2011

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b)

Insulation Resistance Measurement in M? (Using 5000 V Megger) Make & Sl. No of testing kit _______________________ Date of last calibration of kit_______________________ Ambient temp in º C _______________________ IR VALUE

DIELECTRIC POLARISATION ABSORPTION INDEX 15 60 600 COEFFICIENT PI= 600 Sec / 60 REMARKS sec sec sec DAI= 60 Sec / Sec 15 Sec

MAIN WINDING

Combination for Auto transformer a) HV+IV / LV b) HV+IV / E c) LV / E Combination for 3 winding transformer a) HV+IV / LV b) HV+IV / E b) HV+IV+LV / E *Permissible limit of IR value should be > 500 M ? and PI should be >1.25 To 2 X.

at 30°C, DAI should be >1.3

VECTOR GROUP TEST & POLARITY CHECKING

Connect Neutral Point with earth, join 1 RI and 3 R1 Terminals and apply 415 V. 3phase supply to HV Terminals VOLTAGE MEASURED (VOLTS)

TERMINALS

REMARKS

1R1 – 1Y1 1Y1 – 1B1 1B1 – 1R1 3Y1 – 1B1 3Y1 – 1Y1 3R1- N 3Y1 – N 3B1 – N 2R1- N 2Y1 – N 2B1 – N 1R1

Ensure 2R1 – N = 2Y1 – N = 2B1 – N = constant If 3R1 -N > 3Y1 - N > 3B1 - N, AND 3Y1 - 1B1 > 3Y1 - 1Y1 Vector group Ynaod11 is confirmed and polarity verified

3R1 3Y1 3B1 2R1

2B1

1B1

2Y1

1Y1

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MEASUREMENT OF WINDING RESISTANCE (IN OHM)

XI.

Make of testing kit________________________ Date of calibration____________________ Ambient temperature____________________ Temperature of oil____ _____________________ WTI reading

___ __________________________

A) HIGH VOLTAGE SIDE TAP POSITI ON

WINDING RESISTANCE(HV-N) 1R1– 1Y1– 1B1– 2R1 2Y1 2B1

RESISTANCE AT 75º C R Y B

FACTORY VALUE AT 75º C R Y B

RESISTANCE AT 75º C R Y B

FACTORY VALUE AT 75º C R Y B

% DEVIATION R

Y

B

1 2 3 4 5 6 7 8 9b 10 11 12 13 14 15 16 17 REVERSE ORDER TAP WINDING POSITI RESISTANCE(HV-N) ON 1R1– 1Y1– 1B1– 2R1 2Y1 2B1 TAP..…. TAP…… TAP…… TAP……

% DEVIATION R

Y

B

* Formula for calculating the resistance at 75°C: R 75 = RT (235+75)/ (235+T), where RT = Resistance Measured At Winding Temperature T. B) INTERMEDIATE VOLTAGE SIDE

BETWEEN WINDING

RESISTANCE SITE VALUE

RESISTANCE AT 75 °C IN OHMS FACTORY SITE

% DEVIATION

2R1 – N 2Y1 – N 2B1 – N 84 Transformer

No. CF/ICT/01/ R-3 DATED 01/04/2011

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C) LOW VOLTAGE SIDE BETWEEN WINDINGS

RESISTANCE SITE VALUE@ --ºC

RESISTANCE AT 75 °C IN OHMS FACTORY SITE

% DEVIATION

3R1 – 3B1 3Y1 – 3R1 3B1 – 3Y1 NOTE: LV winding resistance at factory measured withou t formation of delta. However measurements carried out at site are after formation of delta. Hence a correction factor of 1.5 times to be applied in site results

Permissible limit: ±5% variation between phases or from Factory test results XII.

MAGNETIC BALANCE TEST

Details of testing kit

________________________ Date of calibration_________________

Apply single phase 230 V across one phase of HV winding terminal and neutral then measure voltage in other two HV terminals across neutral. Repeat the test for each of the three phases. APPLY 1-PH 230V AC ACROSS (1)

2R1 – N: 2Y1 – N: 2B1 – N:

VOLTAGE MEASURED IN VOLTS BETWEEN (2) BETWEEN (3)

2Y1 – N: 2R1 – N: 2Y1 – N:

REMARKS

2B1 – N: 2B1 – N: 2R1 – N:

Note: (1)=(2)+(3), Approx When outer phase is excited, voltage induced in the center phase shall be 50 to 90% of the applied voltage. However, when the center phase is excited then the voltage induced in the outer phases shall be 30 to 70% of the applied voltage. XIII.

FLOATING NEUTRAL VOLTAGE MEASUREMENT

i.

Disconnect the Transformer neutral from the ground and apply 3 phase 415 Volts to the high voltage winding and make the measurement in the IV winding with respect to neutral and neutral point to ground

TAP POSITION

PRIMARY WINDING

Normal (__) Normal (__) Normal (__)

1R – N 1Y – N 1B – N

ii.

VOLTAGE APPLIED

IV WINDING

VOLTAGE MEASURED

REMARKS, IF ANY

2R – N 2Y – N 2B – N N – Earth

Apply 3 phase 415 Volts to the Intermed iate voltage winding and make the measurement in the Tertiary winding with respect to neutral and neutral point to ground

IV WINDING

VOLTAGE APPLIED

2R – N 2Y – N 2B – N

LV WINDING

VOLTAGE MEASURED

REMARKS, IF ANY

3R – N 3Y – N 3B – N N – Earth

No. CF/ICT/01/ R-3 DATED 01/04/2011

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iii. XIV.

Check after the test, neutral reconnected to the ground

Yes

No

MAGNETIZATION CURRENT TEST

i.

Apply 1 Phase, AC supply on HV Te rminals and keep IV and LV open

TAP POSITION

LOWEST

NORMAL

HIGHEST

ii.

VOLTAGE APPLIED IN VOLTS

CURRENT MEASURED IN mAMPS

R-N Y- N B-N R-N Y- N B-N

R - PH Y - PH B - PH R - PH Y - PH B - PH

R-N Y-N B-N

R - PH Y - PH B - PH

REMARK

Apply 1 phase, 415V AC supply on IV Terminal and keep HV & LV open

TAP POSITION

VOLTAGE APPLIED IN VOLTS

CURRENT MEASURED (IN LV SIDE) IN M AMP

2R – 2Y 2Y – 2B 2R – 2B

Normal

R – PH Y – PH B – PH

*If the excitation current is less than 50 milli-Amperes (mAmp), the difference between the two higher currents should be less than 10%. If the excitation current is more than 50 mAmp, the difference should be less than 5%. The value on the outside legs should be within 15% of each other and values for centre leg should not be more than either outside for a three phase transformer. Results between similar single phase units should not vary more than 10%. XV.

VOLTAGE RATIO TEST

Make of testing kit

_______________________ Date of calibration_____________________

Ambient temperature____________ _____

Temperature of oil______ __________________

Remarks: To be done by Automatic Turns ratio meter i.

RATIO : HV / IV

POS.

VOLTAGE APPLIED

VOLTAGE MEASURED

1R-N

2R-N

1Y-N

1B-N

2Y-N

2B-N

RATIO R

Y

FACTORY RATIO B

R

Y

B

% DEVIATION R

Y

B

1 2 3 4 5 6 86 Transformer

No. CF/ICT/01/ R-3 DATED 01/04/2011

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7 8 9 10 11 12 13 14 15 16 17 REVERSE SIDE TAP NO……. TAP NO……. TAP NO……. TAP NO…….

ii.

POS.

RATIO : HV / LV VOLTAGE APPLIED

VOLTAGE MEASURED

1R-N

3R-3Y

1Y-N

1B-N

3Y-3B

3R-3B

RATIO R

Y

FACTORY RATIO B

R

Y

B

% DEVIATION R

Y

B

Lowest Normal Highest iii. POS.

RATIO : IV / LV VOLTAGE APPLIED

VOLTAGE MEASURED

2R-N

3R-3Y

2Y-N

2B-N

3Y-3B

3R-3B

RATIO R

Y

FACTORY RATIO B

R

Y

B

% DEVIATION R

Y

B

Lowest Normal Highest Remarks (if any):

*The variation of result should be within ± 0.5 % from specified values or factory test result. XVI.

OIL CHARACTERISTICS

(Sample to be taken prior to charging to Transformer and it should fulfill the recommendations as per IS 1865 /IEC 60422) DATE OF OIL SAMPLING

Permissible Limit

B.D.V.

70KV(min)

MOISTURE

TAN DELTA

RESISTIVITY

INTERFACIAL TENSION

5 PPM(Max)

0.01 at 90º C (Max)

6x 10 ^12 ? -CM at 90º C (Min)

0.0 35 N/m at 27ºC (Min)

No. CF/ICT/01/ R-3 DATED 01/04/2011

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XVII.

DISSOLVED GAS ANALYSIS

DISSOLVED GASES

JUST BEFORE CHARGING

JUST AFTER CHARGING

24 HRS AFTER CHARGING

7 DAYS AFTER CHARGING


H2 CH4 CO CO2 C2H4 C2H6 C2H2 O2 N2 TCG

* TCG should be below 1% XVIII. TEST ON OLTC SL.N O

1

2 3 4 5 6 7 8 9 10 11 12 XIX.

STATUS

DESCRIPTION OK

Visual inspection of equipment Manual operation on all taps ( local ) with confirmation of the no. Of revolutions and locking at extreme taps Over load device of driving motor Local operation (electrical) Remote operation (electrical) Tap position indicator Check operation with master follower Scheme ( parallel operation ) Out of step relay Step by step contactor Limit switch Winding resistance at all taps Continuity test of winding during one complete cycle of operation OPERATIONAL TEST OF OTHER EQUIPMENTS

i.

Checking of cooling Equipments

SL.NO

STATUS

DESCRIPTION OK

1 2

REMARKS

NOT OK

NOT OK

Rotation direction of Pumps Rotation direction of Fans ii.

Protection Check

EQUIPMENT FAN NO

SETTING VALUE

PICKUP VALUE

SINGLE PHASING PREVENTION CHECK

1 2 3 88 Transformer

No. CF/ICT/01/ R-3 DATED 01/04/2011

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4 5 6 7 8 9 10 11 12 13 14 15 16 Pump No. 1 2 3 4

XX.

INSULATION RESISTANCE MEASUREMENT OF BUSHING CT’S(USING 500V MEGGER)

MEASUREMENT BETWEEN

Earth - Core I Earth - Core II Earth - Core III Earth - Core IV

MEASUREMENT BETWEEN

Earth - Core I Earth - Core II Earth - Core III Earth - Core IV

MEASUREMENT BETWEEN

Core I – Core II Core I – Core III Core I – Core IV Core II – Core III Core II – Core IV Core III – Core IV

UNIT

HV R–Ø

IV

Y-Ø

B-Ø

R-Ø

Y-Ø

B-Ø

M? M? M? M?

UNIT

LV R-Ø

Y-Ø

NEUTRAL

B-Ø

M? M? M? M?

HV

IV

UNIT R–Ø

Y-Ø

B-Ø

R-Ø

Y-Ø

B-Ø

M? M? M? M? M? M?

No. CF/ICT/01/ R-3 DATED 01/04/2011

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MEASUREMENT BETWEEN

Core I – Core II Core I – Core III Core I – Core IV Core II – Core III Core II – Core IV Core III– Core IV XXI.

LV

UNIT

R-Ø

Y-Ø

B-Ø

M? M? M? M? M? M?

CONTINUITY TEST OF BUSHING CT’S (in ? )

: OK / NOT OK

Continuity, Check between Terminals CORE

BETWEEN TERMINAL

Core – I Core – II Core – III Core – IV

1S1–1S2 2S1–2S2 3S1–3S2 4S1–4S2

CORE

BETWEEN TERMINAL

Core – I Core – II Core – III Core – IV XXII.

HV Y-Ø

R-Ø

B-Ø

LV Y – PHASE

R – PHASE

R-Ø

B – PHASE

IV Y-Ø

B-Ø

NEUTRAL

1S1–1S2 2S1–2S2 3S1–3S2 4S1–4S2

SECONDARY WINDING RESISTANCE OF BUSHING CT’S (IN OHM)

i. CORE

HV side BETWEEN TERMINAL

UNIT

1S1 – 1S2 2S1 – 2S2 3S1 – 3S2 4S1 – 4S2 IV side

CORE

BETWEEN TERMINAL

UNIT

1S1 – 1S2 2S1 – 2S2 3S1 – 3S2 4S1 – 4S2

? ? ? ?

iii. CORE

Core I Core II Core III Core IV

FACTORY

Y-Ø SITE

FACTORY

B-Ø SITE

FACTORY

SITE

? ? ? ?

Core I Core II Core III Core IV ii.


R-Ø

R-Ø FACTORY

Y-Ø SITE

FACTORY

SITE

FACTORY

B-Ø SITE

FACTORY

SITE

FACTORY

SITE

LV side BETWEEN TERMINAL

UNIT

1S1 – 1S2 2S1 – 2S2 3S1 – 3S2 4S1 – 4S2

? ? ? ?

90 Transformer

R-Ø FACTORY

Y-Ø

B-Ø SITE

No. CF/ICT/01/ R-3 DATED 01/04/2011

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iv.

Neutral Side BETWEEN TERMINAL

CORE

Core I

1S1 – 1S2

UNIT

FACTORY

SITE

?

Factory Type Test Report Ref. No._________________________________ XXIII.

POLARITY TEST OF BUSHING CT’S

With 1.5 V DC supply

(Connect +ve at P1 and –ve at P2)

i. CORE


BETWEEN

1S1 (+ve) 2S1 (+ve) 3S1 (+ve) 4S1 (+ve)

R-Ø

HV Y-Ø

B-Ø

R-Ø

IV Y-Ø

B-Ø

1S2 (-ve) 2S2 (-ve) 3S2 (-ve) 4S2 (-ve)

ii. CORE


LV

BETWEEN

1S1 (+ve) 2S1 (+ve) 3S1 (+ve) 4S1 (+ve)

R-Ø

Y-Ø

NEUTRAL

B-Ø

1S2 (-ve) 2S2 (-ve) 3S2 (-ve) 4S2 (-ve)

XXIV. CURRENT RATIO TEST Primary Injection through Primary Injection Kit at Primary Terminal P1 – P2 Measure current on the secondary Terminals i.

HV side R – Phase side CORE S1 - S2

Core I (1S1 – 1S2) Core II (2S1 – 2S2) Core III (3S1 – 3S2) Core IV (4S1 – 4S2)

PRIMARY %

CURRENT ACTUAL

SECONDARY CURRENT

THEORETICAL RATIO

ACTUAL RATIO

% OF ERROR

20% 40% 80% 20% 40% 80% 20% 40% 80% 20% 40% 80%

No. CF/ICT/01/ R-3 DATED 01/04/2011

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ii.

HV side Y – Phase

CORE S1 - S2

PRIMARY %

CURRENT ACTUAL

SECONDARY CURRENT

THEORETICAL RATIO

ACTUAL RATIO

% OF ERROR

SECONDARY CURRENT

THEORETICAL RATIO

ACTUAL RATIO

% OF ERROR

SECONDARY CURRENT

THEORETICAL RATIO

ACTUAL RATIO

% OF ERROR

20% 40% 80% 20% Core II 40% (2S1 – 2S2) 80% 20% Core III 40% (3S1 – 3S2) 80% 20% Core IV 40% (4S1 – 4S2) 80% iii. HV side B – Phase Core I (1S1 – 1S2)

CORE S1 - S2

PRIMARY %

CURRENT ACTUAL

20% 40% 80% 20% Core II 40% (2S1 – 2S2) 80% 20% Core III 40% (3S1 – 3S2) 80% 20% Core IV 40% (4S1 – 4S2) 80% IV side R – Phase iv. Core I (1S1 – 1S2)

CORE S1 - S2

Core I (1S1 – 1S2) Core II (2S1 – 2S2) Core III (3S1 – 3S2) Core IV (4S1 – 4S2) 92 Transformer

PRIMARY %

CURRENT ACTUAL

20% 40% 80% 20% 40% 80% 20% 40% 80% 20% 40% 80% No. CF/ICT/01/ R-3 DATED 01/04/2011

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IV side Y – Phase

v. CORE S1 - S2

PRIMARY %

Core I (1S1 – 1S2) Core II (2S1 – 2S2) Core III (3S1 – 3S2) Core IV (4S1 – 4S2)

20% 40% 80% 20% 40% 80% 20% 40% 80% 20% 40% 80%

vi. CORE S1 - S2

CURRENT ACTUAL

SECONDARY CURRENT

THEORETICAL RATIO

ACTUAL RATIO

% OF ERROR

SECONDARY CURRENT

THEORETICAL RATIO

ACTUAL RATIO

% OF ERROR

IV side B – Phase PRIMARY %

CURRENT ACTUAL

20% 40% 80% 20% 40% 80% 20% 40% 80% 20% 40% 80% Permissible limit ±3% Core I (1S1 – 1S2) Core II (2S1 – 2S2) Core III (3S1 – 3S2) Core IV (4S1 – 4S2)

XXV.

MAGNETISING CURVES PERFORMANCE (Not to be done for metering Core) Knee Point Voltage (KVp) = ………………..Volt i.

HV Side R – Phase VOLTAGE

TO BE APPLIED

0.25 x KVp 0.50 x KVp 0.75 x KVp 1.00 x KVp 1.10 x KVp

ACTUAL VALUE

UNIT

CORE – I 1S1-1S2

CURRENT MEASUREMENT CORE – II CORE – III 2S1-2S2 3S1-3S2

CORE – IV 4S1-4S2

mA mA mA mA mA

No. CF/ICT/01/ R-3 DATED 01/04/2011

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ii.

HV Side Y – Phase CORE – I 1S1-1S2


CORE – IV 4S1-4S2

CORE – I 1S1-1S2


CORE – IV 4S1-4S2

CORE – I 1S1-1S2


CORE – IV 4S1-4S2

CORE – I 1S1-1S2


CORE – IV 4S1-4S2

CORE – I 1S1-1S2


CORE – IV 4S1-4S2

VOLTAGE TO BE APPLIED

ACTUAL VALUE

UNIT

0.25 x KVp mA 0.50 x KVp mA 0.75 x KVp mA 1.00 x KVp mA 1.10 x KVp mA iii. HV Side B – Phase VOLTAGE TO BE APPLIED

ACTUAL VALUE

0.25 x KVp 0.50 x KVp 0.75 x KVp 1.00 x KVp 1.10 x KVp iv. IV Side R – Phase

UNIT

mA mA mA mA mA


ACTUAL VALUE

0.25 x KVp 0.50 x KVp 0.75 x KVp 1.00 x KVp 1.10 x KVp v. IV Side Y – Phase

UNIT

mA mA mA mA mA


ACTUAL VALUE

0.25 x KVp 0.50 x KVp 0.75 x KVp 1.00 x KVp 1.10 x KVp vi. IV Side B – Phase

UNIT

mA mA mA mA mA



ACTUAL VALUE

UNIT

mA mA mA mA mA

Note: 1.0 CT should not saturate at 110% of Knee Point Voltage (KVp) 2.0 If Knee Point Voltage is not mentioned then Knee Point Current may be taken into consideration. 94 Transformer

No. CF/ICT/01/ R-3 DATED 01/04/2011

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XXVI.

CONTACT RESISTANCE MEASUREMENT at 100 Amps CONTACT RESISTANCE

UNITS

R-Ø

Y-Ø

B-Ø

µ? µ? µ? µ? µ?

Across HV Bushing Terminal Joint Across IV Bushing Terminal Joint Across LV Bushing Terminal Joint Across Neutral Connection Point Across Surge Arrester Connection

The value of Contact Resistance should not be more than 10 Micro – ohms per Joint / Connector XXVII. BUSHING DETAILS STYLE NO / DRAWING NO. DETAILS

HIGH VOLTAGE SIDE Y-Ø

R-Ø

INTERMEDIATE VOLTAGE SIDE R-Ø Y-Ø B-Ø

B-Ø

Make Type Sl. No. DETAILS

LOW VOLTAGE SIDE Y-Ø

R-Ø

B-Ø

Make Type Sl. No. XXVIII. TAN DELTA AND CAPACITANCE MEASUREMENT OF BUSHING

Make of testing kit ____________________________ Date of calibration _____________________________ Ambient temperature _____________________________ i.

HV side CAPACITANCE (MEASURED VALUE) R-Ø

VOLTAGE SITE

FACTORY

Y–Ø SITE

FACTORY

B-Ø SITE

REMARKS

FACTORY

Measurement of C1 2 KV KV

10 Measurement of C2

1 KV TAN ä (MEASURED VALUE) VOLTAGE

R-Ø SITE

FACTORY

Y–Ø SITE

FACTORY

B-Ø SITE

REMARKS

FACTORY

Measurement of C1 2 KV 10 KV Measurement of C2 Tan ä

1 KV No. CF/ICT/01/ R-3 DATED 01/04/2011

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ii.

IV side CAPACITANCE (MEASURED VALUE)

VOLTAGE

R-Ø SITE

Y–Ø

FACTORY

SITE

FACTORY

B-Ø SITE

REMARKS

FACTORY

Measurement of C1 2 KV Measurement of C2 1 KV TAN ä (MEASURED VALUE) R-Ø

VOLTAGE

Y–Ø

FACTORY

SITE

SITE

FACTORY

B-Ø SITE

REMARKS

FACTORY

Measurement of C1 2 KV Measurement of C2 Tan ä 1 KV iii.

LV side CAPACITANCE (MEASURED VALUE)

VOLTAGE

R-Ø SITE

Y–Ø

FACTORY

SITE

FACTORY

B-Ø SITE

REMARKS

FACTORY

Measurement of C1 2 KV Measurement of C2 1 KV TAN ä (MEASURED VALUE) VOLTAGE

R-Ø SITE

Y–Ø

FACTORY

SITE

FACTORY

B-Ø SITE

REMARKS

FACTORY

Measurement of C1 2 KV Measurement of C2 Tan ä 1 KV C2 values shall be only for record purpose. Factory test report ref no: *ACCEPTABLE LIMIT FOR Tan ä1:-0.004 & Tan ä2:-0.01 XXIX.

TAN DELTA AND CAPACITANCE MEASUREMENT OF WINDING

Make of testing kit

__________ __________________

Date of calibration

_____________________________

Ambient temperature _

___________________ _________

96 Transformer

No. CF/ICT/01/ R-3 DATED 01/04/2011

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VOLTAGE

WINDING COMBINATION

CAPACITANCE

TEST MODE

SITE

2 KV 10 KV 2 KV 10 KV 2 KV 10 KV 2 KV 10 KV 2 KV 10 KV 2 KV 10 KV

HV-IV/ LV

UST

HV-IV/ LV+G

GST

HV-IV/ LV with Guard

GSTg

HV-IV/LV

UST

LV/ HV-IV+G

GST

LV/ HV-IV with Guard

GSTg

FACTORY

TAN DELTA * SITE

REMARK

FACTORY

Factory Test Report Ref. No.: ______________________________________ * Should be comparable (+/- 0.001) with factory value subjected to max of 0.005. XXX. SHORT CIRCUIT IMPEDANCE TEST Make of testing kit Date of calibration

__ ___________________________

Ambient temperature _ Temperature of Oil i.

__________ __________________

___________________ _________ _____________________________

HV TO IV

TAP NUMBER

1U1 ( R )

1V1 (Y)

1W1 (B)

(IV OF R Ô AND N SHORTED, LV OPEN)

(IV OF Y Ô AND N SHORTED, LV OPEN)

(IV OF B Ô AND N SHORTED, LV OPEN)

VOLTAGE in Volt

CURRENT in Amp

VOLTAGE in Volt

CURRENT in Amp

VOLTAGE in Volt

CURRENT in Amp

1 9b 17 ii.

IV TO LV

Tap No 9b SUPPLY

SHORT ALL 3 LV BUSHINGS, HV OPEN

2U1-N, ……....V

………………………………A

2V1-N,……….V 2W1-N, ……...V

No. CF/ICT/01/ R-3 DATED 01/04/2011



…………………………A ………………………A

Transformer

97

Doc No. D-2-01-03-01-03

iii.

HV TO LV

Tap No 9b SHORT ALL 3 LV OPEN

SUPPLY 1U1-N, ……....V



………………………………A

1V1-N,……….V

…………………………A

1W1-N, ……...V

………………………A

Tap No 17 SUPPLY


1U1-N, ……....V

………………………………A


1V1-N,……….V


…………………………A

1W1-N, ……...V

………………………A

Tap No 1 SUPPLY


1U1-N, ……....V

………………………………A


1V1-N,……….V


…………………………A

1W1-N, ……...V

………………………A

XXXI. PROTECTION AND ALARMS i. SL.NO

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 ii.

DEVICE

Excessive winding temperature. Excessive oil temperature. Oil flow failure Pressure relief valve Main tank Buchholz relay OLTC Buchholz relay Fan failure Low oil level (MOG) Differential relay Over load relay Earth fault relay ( ref ) Over current relay Inter trip , if any Trip free check Backup over current Over flux

SET FOR ALARM TRIP

100 90 NA NA

NA NA NA NA NA NA

Protection setting applied as per engg.approved settings

98 Transformer

PROVED ALARM TRIP

110 100 NA NA

NA

NA NA NA NA NA

NA NA NA NA

NA NA NA NA

Yes

No

Remarks

No. CF/ICT/01/ R-3 DATED 01/04/2011

Doc No. D-2-01-03-01-03

iii.

Stability test of differential and REF protection

Ok

Not Ok

Remarks

NOTE : Prove the tripping of associated brea kers by actual operation of the various devices and relays as per the schemes. XXXII. FREQUENCY RESPONSE ANALYSIS (FRA) i.

Carried out after completion of all commissioning activities

Yes

No

Remarks

ii.

Interpretation of test results carried out

Yes

No

Remarks

Yes

No

Remarks

Yes

No

Remarks

Yes

No

Remarks

Yes

No

Remarks

iii. Test results matching with the factory results

iv. Factory & site FRA test report available at site

XXXIII. ALL ELECTRICAL TEST RE SULTS COMPARED WITH FACTORY TEST RESULTS & FOUND TO BE IN ORDER XXXIV.

CHECKS AFTER CHARGING OF TRANSFORMER

Record the following after charging i.

Any abnormal sound emanating from the transformer

ii.

iii.

No load current at relay terminal R-Ø

A

Y-Ø

A

B-Ø

A

Temperature at the time of charging OTI

ºC

WTI

ºC

AMBIENT

ºC

iv.

Maximum temperature after 24 hours____________º C

v.

OLTC electrical operation checked in idle charged condition from minimum position to maximum position & back to normal position Yes No Remarks

No. CF/ICT/01/ R-3 DATED 01/04/2011

Transformer

99

Doc No. D-2-01-03-01-03

vi.

Thermo vision scanning done at least after 24 hours of loading & repeated after one week. Yes

No

Remarks

XXXV. FINAL DOCUMENTATION REVIEW Yes

No

ii. Final documents of Pre- Commissioning checks reviewed and approved

Yes

No

iii. Document regarding spares equipment, O&M manuals etc available at site

Yes

No

Yes

No

i.

Factory test results are available

iv. After modification, if any, “As built Drawings” are available at site

Signature:

Signature:

Signature:

Signature:

Name:

Name:

Name:

Name:

Designation:

Designation:

Designation:

Designation:


(Erection Agency)


(POWERGRID Commissioning. Team) Members:

100 Transformer

No. CF/ICT/01/ R-3 DATED 01/04/2011

Doc No. D-2-01-03-01-03

PRE-COMMISSIONING FORMATS FOR REACTOR I.

GENERAL DETAILS

Region: LOA No. : Sr. No.: Year of Manufacture: Voltage Class : Type of Neutral Grounding: Oil type: Quantity of Radiator Date of Starting of Erection:

CHECK LIST OF ELECTRICAL TESTS CARRIED OUT FOR REACTOR

II. S.N

a b c d e f g h i j k l m n o p q r

DETAILS Sub-Station: Make: Type: Rating: Cooling Type: Oil Make: Oil quantity: Date of Receipt at site: Date of Completion of Erection and Oil filling:

NAME OF TEST

PERFORMED (YES/NO)


Insulation Resistance Measurement Tan Delta & Capacitance Measurement Of Bushing Tan Delta & Capacitance Measurement Of Windings Tan Delta & Capacitance Measurement Of NGR Windings Measurement of Winding Resistance Measurement of Winding Resistance of NGR Magnetisation Current Test Insulation Resistance Measurements Of Bushing Cts Continuity Test Of Bushing Cts Secondary Winding Resistance Of Bushing Cts Polarity Test Of Bushing Cts Current Ratio Test Magnetizing Curves Performance Contact Resistance Measurement Vibration Measurement Protection And Alarm Tests Stability Test Of Differe ntial And Ref Protection Frequency Response Analysis

Signature:

Signature:

Signature:

Signature:

Name:

Name:

Name:

Name:

Desgn.:

Desgn.:

Desgn.:

Desgn.:


(Erection Agency)



No. CF/SR/02/ R-3 DATED 01/04/2011

Reactor 101

Doc No. D-2-01-03-01-03

III.

CHECKS AFTER RECEIPT OF REACTOR AT SITE:

A) N2 PRESSURE & DEW POINT RECORD N2 PRESSURE

DEW POINT

REMARKS

During dispatch at factory After receipt at site Storage at site before commissioning Please write 'NIL' in case of No Remarks NOTE: N2 pressure and dew point should be within permissible range as per graph provided by manufacturer and also given in os doc no d-2-03-xx-01-01 rev-01. During storage at site, dew point has to be measured whenever any drop inN2 pressure is observed. During storage at site before commissioning, N2pressure has to be measured daily and record to be maintained in a separate sheet. Refer graph 2.1.3 fig.1

B) IMPACT RECORDER ANALYSIS STATUS

Received in healthy condition at site

Yes

No

Analysis report received from manufacturer before charging

Yes

No

BRIEF ANALYSIS

Note: Impact Recorder should be detached from the Reactor preferably when the main unit has been placed on its foundation.

Permissible limit for maximum shock is ±3G for any axis. C) CORE INSULATION TEST APPLY 1 kV DC BETWEEN CL & CC + G INSULATION VALUE BETWEEN CC-G BETWEEN CL-G BETWEEN CC-CL

Note: Shorting link between CC, CL & G to be removed and IR value to be taken between CC-G, CL-G & CC-CL

(Recommended value > 10 M? ) D) INTERNAL INSPECTION STATUS YES NO

INTERNAL INSPECTION

Details photographs of all visible parts /components are taken during internal inspection.(refer procedure2.1.6) Any abnormality observed during internal inspection Matter referred to manufacturer, CC-ENGG and CC-OS Details of abnormalities notice if any: 102 Reactor

No. CF/SR/02/ R-3 DATED 01/04/2011

Doc No. D-2-01-03-01-03

CHECKS /PRECAUTIONS DURING ERECTION :

IV.

a. Active part of Reactor should be minimum exposed to atmosphere b. Use of dry air generator / dry air cylinders, during exposure of active part of Reactor to atmosphere.

Yes

c. While entering in Reactor tank, availability of proper Oxygen is checked

Yes

No

Remarks

d. Reactor kept sealed with N2 in between different erection activities

Yes

No

Remarks

No

Remarks


V.

SL. NO.

1

STATUS DESCRIPTION OF ACTIVITY YES

7

Reactors and its Auxiliaries are free from visible defects on physical Inspection All fittings as per out line General Arrangement Drawing Check Main Tank has been provided with double earthing Check neutral is grounded through separate connections. Ensure metallic requirements as per specification (e.g. Cu) in earthing strips used Check that Marshalling Box, Radiator Bank Pump & Fan Motor etc. has been earthed All nuts and bolts are tightened correctly as per specified torque (as per manufacturers recommendation) Check tightness of Terminal Connectors

8

Check leveling of Reactor and its accessories

9

11

Erection Completion Certificate along with list of outstanding activities reviewed Any Paint removed / scratched in transit has been touched up Bushings are clean and free from physical damages

12

Oil level is correct on all Bushings

13

Check Hermitically sealing is intact in all Bushings

14

Check oil leakage through any Joints / Valves etc.

15

Check oil drain valves are properly closed and locked

16

Check oil level in Main and Conservator tank

17

Check OTI and WTI pockets and replenish the oil, if required

2 3 4

5 6

10

No. CF/SR/02/ R-3 DATED 01/04/2011

NO

REMARK DEFICIENCIES, IF ANY

Reactor 103

Doc No. D-2-01-03-01-03

18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33

34 35 36

37 38 39 40 41

Check all valves for their opening & closing sequence Check the colour of the breather silica gel (blue when dry) Check availability of oil in the breather cup Check all rollers are locked and tack welded with rails (wherever applicable) Check busing test tap is grounded Check no debris, loose T & P and oil strains on and around the Reactor Check door seals of Marshalling Box is intact and all cable gland plates unused holes are sealed Check that pressure relief valve is correctly mounted Ensure unused secondary cores of Bushing CT’s, if any, has been shorted Check CT star point has been formed properly and grounded at one end only as per scheme Check that permanent and adequate lighting arrangements are ready Check that labeling and identification is permanent and satisfactory Check that Buchholz Relay is correctly mounted with arrow pointing towards conservator Check cables are properly fixed and ensure cable entry at the bottom Ensure all Power and Control cable Terminals are tightened Check all cables and Ferrules are provided with Number as per Cable Schedule (Cross Ferruling to be checked) Check that all cables are correctly glanded Check external cabling from Junction Box to Relay / Control Panel completed Check that air has been released from the Radiators and their headers/OLTC Buchholz relay/Main tank/tank/Bushing turrets etc Check Fire Protection System & Emulsifier systems is adequate & ready Check that CC-CL & G are shorted Check that all radiator bank valves on top and bottom headers are open Change over operation of ac supply from source- I to source-II checked Check the flanges of bushing for any crack after fixing

104 Reactor

No. CF/SR/02/ R-3 DATED 01/04/2011

Doc No. D-2-01-03-01-03

42

Calibration of OTI & WTI performed as per procedure Check various interlocks provided with Fire Fighting as per the schematic Ref. Drg. No._____________________

43

VI.

Description of Interlocks

Checked

MEASUREMENT OF EARTH RESISTANCE OF ELECTRODE LOCATION

VALUE

With Grid (Earth Pit -1) Without Grid (Earth Pit -1) (Neutral Earth ) With Grid (Earth Pit -2) Without Grid (Earth Pit -2) (Neutral Earth)

Permissible limit with grid < 1 ohm VII.

DETAILS OF RELAYS/ CONTACTORS USED: SCHEMATIC DRAWING NO.

CIRCUIT REFERENCE

VIII.

MAKE

SERIAL NO.

TYPE

NO+NC

EVACUATING AND OIL FILLING

a) Before filling oil, each drum has been physically checked for free moisture and appearance

Yes

No

b) Details of oil filter machine Make _____________________ SL.NO

1 2 3 4

Capacity________________________


REMARKS / READING

Changing of Lubricating oil of vacuum pump Cleaning of Filter packs Flushing of whole filter machine with fresh oil Vacuum obtained without load (milli bar)

c) Vacuum pump for evacuation of Reactor SL.NO

1 2 3 4


REMARKS / READING

Changing of Lubricating oil of vacuum pump Vacuum obtained without load (milli bar) Diameter of vacuum hose (50 mm) Employ of Dry ice chamber

No. CF/SR/02/ R-3 DATED 01/04/2011

Reactor 105

Doc No. D-2-01-03-01-03

Oil storage tank

d)

Capacity_____________________

Quantity_________________________


SL.NO

1 2 3 4

REMARKS / READING

Silica gel breather provided in the tank Any opening left uncovered Inside painted or not Cleanliness of inside of pipes/ hoses to the storage tank

e) Exposure during erection DESCRIPTION OF WORKS

SL.NO

First day exposure ( in hrs) Second day exposure ( in hrs) Third Day exposure ( in hrs) N2 pressure applied after each days erection work ( in PSI) 5 Ambient Temperature (in degC) 6 Average Relative Humidity 7 Weather Condition

REMARKS / READING

1 2 3 4

Rainy / Stormy / Cloudy / Sunny

f) N2 sealing in case of delay in oil filling i. DESCRIPTION OF WORKS

SL.NO

No. of Cylinders used for displacing the air inside the tank N2 admitted from bottom valve Valve at diametrically opposite end at top kept open No. of Cylinders used for building up 2 PSI

1 2 3 4 ii. Sl.No

1 2 3 4 5

6

REMARKS / READING

Schedule for Vacuum & Tightness Test INSPECTION ACTIONS

DATE

TIME

REMARKS / READING

Starting of evacuation on complete unit Stopping of evacuation below the pressure of 0.3 kPa (3 mbar) Pressure P1 in kPa after 1 hour of stopping evacuation Pressure P2 in kPa after half an hour of reading pressure P1 Leakage = (P2-P1) x V , V=Oil quantity in Cu mtr *If leakage >3.6, continue evacuating If leakage < 3.6Similar action may be carried out for 2 to3 times for confirmation. Start of Vacuum after N2 pressure reaching below 0.13kPa(1 torr)

106 Reactor

No. CF/SR/02/ R-3 DATED 01/04/2011

Doc No. D-2-01-03-01-03

7

Break of vacuum * Vacuum to be kept for 12 hrs Up to 145 KV, 24 hrs for 145 to 220kV and 36 hrs for 420 kV and above iii.

Schedule for Oil filling and Settling

Sl.No

1 2 3 4

INSPECTION ACTIONS

DATE

TIME

REMARKS / READING

Oil Filling in Main Tank Oil filling in Conservator tank Start of oil settling End of oil settling * Minimum settling time to be given 12 hrs for 145 KV ,48 hrs for 145 to 420kV and 120 hrs for above 420 kV . iv.

Record of drying out process (if carried out)

Drying out started on date:

Time:

Ambient temp: Hourly reading to be taken DATE

TIME

VACUUM READING IN FILTRATION MACHINE

VACUUM READING IN TRANSFORMER TANK

OTI OF TANK

CONDENSATE COLLECTED TOTAL / RATE

REMARKS & SIGN OF MTC ENGINEER

Record of filtration and Dry out shall be kept in a register and shall be made a part of the Precommissioning document. IX.


a)

Insulation Resistance Measurement of Cable and others (Using 500 Volt Megger) Make & Sl. No of testing kit _____________________ Date of last calibration of the kit Ambient temp in º C

SL. NO.

A B

_____________________ _____________________

DESCRIPTION

STATUS YES

NO

REMARKS, IF ANY

Control wiring Cooling System a) Motor Fan b) Motor Pump c) Control wiring

* Permissible limit of IR value should be > 50 M ? No. CF/SR/02/ R-3 DATED 01/04/2011

Reactor 107

Doc No. D-2-01-03-01-03

b)

Insulation Resistance Measurement in M? (Using 5000 V Megger) Make & Sl. No of testing kit _______________________ Date of last calibration of the kit Ambient temp in º C

_______________________ _______________________ IR VALUE

MAIN WINDING

15 sec 60 sec 600 sec

DIELECTRIC POLARISATION ABSORPTION INDEX COEFFICIENT PI= 600 Sec / 60 DAI= 60 Sec / 15 Sec Sec

REMARKS

a) HV / E b)NGR WINDING

*Permissible limit of IR value should be >500 M ? and PI should be >1.25 To 2

X.

at 30°C,

DAI should be >1.3

MEASUREMENT OF WINDING RESISTANCE (IN OHM) Make of testing kit

____________________ Date of calibration____________________

Ambient temperature ___________________ Temperature of oil___________________ WTI reading ____ _________________________

i.

WINDING RESISTANCE OF REACTOR WINDING

WINDING RESISTANCE (HV-N) RØ YØ BØ

ii.

*RESISTANCE AT 75º C RØ

Y

BØ

FACTORY VALUE AT 75º C RØ

YØ

BØ

% DEVIATION RØ

YØ

BØ

WINDING RESISTANCE OF NGR WINDING

WINDING RESISTANCE (HV-N) RØ YØ BØ

*RESISTANCE AT 75º C RØ

Y

BØ

FACTORY VALUE AT 75º C RØ

YØ

BØ

% DEVIATION RØ

YØ

BØ

* Formula for calculating the resistance at 75°C: R 75 = RT (235+75)/ (235+T), where RT = Resistance Measured At Winding Temperature T. Permissible limit: ±5% variation between phases or from Factory test results

108 Reactor

No. CF/SR/02/ R-3 DATED 01/04/2011

Doc No. D-2-01-03-01-03

MAGNETIZATION CURRENT TEST

XI.

Make of testing kit______________________ Date of calibration___________________ Ambient temperature ______________________ Temperature of oil_______________ VOLTAGE APPLIED IN VOLTS

R-N Y- N B-N NGR

CURRENT MEASURED IN mAMPS

REMARK

R - PH Y - PH B - PH

If the excitation current is le ss than 50 milli-Amperes (mAmp), the difference between the two higher currents should be less than 10%. If the excitation current is more than 50 mAmp, the difference should be less than 5%. The value on the outside legs should be within 15% of each other and values for centre leg should not be more than either outside for a three phase reactor. Results between similar single phase units should not vary more than 10%.

OIL CHARACTERISTICS

XII.

(Sample to be taken prior to charging to Reactor and it should fulfill the recommendations as per IS 1865 /IEC 60422 ) DATE OF OIL SAMPLING

Permissible Limit

B.D.V.

70KV(min)

MOISTURE

TAN DELTA

RESISTIVITY

5 PPM(Max)

0.01 at 90º C (Max)

6x 10 ^12 ? CM at 90º C (Min)

INTERFACIAL TENSION

0.0 35 N/m at 27ºC (Min)

XIII. DISSOLVE GAS ANALYSIS DISSOLVE GASES

JUST BEFORE CHARGING

JUST AFTER CHARGING

24 HRS AFTER CHARGING



H2 CH4 CO CO2 C2H4 C2H6 C2H2 O2 N2 *TCG * TCG should be below 1% XIV.

OPERATIONAL TEST OF OTHER EQUIPMENTS i.

SL.NO

Checking of cooling Equipments STATUS

DESCRIPTION OK

1

REMARK

NOT OK

Rotation direction of Fans

No. CF/SR/02/ R-3 DATED 01/04/2011

Reactor 109

Doc No. D-2-01-03-01-03

XV.

INSULATION RESISTANCE MEASUREMENT OF BUSHING CT’S(USING 500V MEGGER)

i.

MEASUREMENT BETWEEN

HV

UNIT

R–Ø

Y-Ø

B-Ø

M? M? M? M?

Earth - Core I Earth - Core II Earth - Core III Earth - Core IV ii.

HV MEASUREMENT BETWEEN

UNIT R–Ø

Core I – Core II Core I – Core III Core I – Core IV Core II – Core III Core II – Core IV Core III – Core IV XVI.

Y-Ø

B-Ø

M? M? M? M? M? M?

CONTINUITY TEST OF BUSHING CT’S (in ? )

Continuity, Check between Terminals CORE

BETWEEN TERMINAL

Core – I Core – II Core – III Core – IV

OK / NOT OK HV Y-Ø

R-Ø

B-Ø

1S1–1S2 2S1–2S2 3S1–3S2 4S1–4S2

XVII. SECONDARY WINDING RESISTANCE OF BUSHING CT’S (IN OHM)

HV side

i. CORE


BETWEEN TERMINAL

UNIT

1S1 – 1S2 2S1 – 2S2 3S1 – 3S2 4S1 – 4S2

? ? ? ?

ii.

R-Ø

Y-Ø

FACTORY

SITE

FACTORY

B-Ø SITE

FACTORY

SITE

Neutral Side

CORE

Core I

BETWEEN TERMINAL

1S1 – 1S2

UNIT FACTORY

SITE

?

Factory Type Test Report Ref. No._________________________________

XVIII. POLARITY TEST OF BUSHING CT’S With 1.5 V DC supply CORE

Core I 110 Reactor

(Connect +ve at P1 and –ve at P2)

BETWEEN

R-Ø

HV Y-Ø

B-Ø

1S1 (+ve) 1S2 (-ve) No. CF/SR/02/ R-3 DATED 01/04/2011

Doc No. D-2-01-03-01-03

Core II 2S1 (+ve) 2S2 (-ve) Core III 3S1 (+ve) 3S2 (-ve) Core IV 4S1 (+ve) 4S2 (-ve) XIX.

CURRENT RATIO TEST

Primary Injection through Primary Injection Kit at Primary Terminal P1 – P2 Measure current on the secondary Terminals i.

HV side R – Phase side CORE S1 - S2

Core I (1S1 – 1S2) Core II (2S1 – 2S2) Core III (3S1 – 3S2) Core IV (4S1 – 4S2) ii.

PRIMARY %

CURRENT ACTUAL

SECONDARY CURRENT

THEORETICAL RATIO

ACTUAL RATIO

% OF ERROR

CURRENT ACTUAL

SECONDARY CURRENT

THEORETICAL RATIO

ACTUAL RATIO

% OF ERROR

CURRENT ACTUAL

SECONDARY CURRENT

THEORETICAL RATIO

ACTUAL RATIO

% OF ERROR

20% 40% 80% 20% 40% 80% 20% 40% 80% 20% 40% 80%

HV side Y – Phase CORE S1 - S2

Core I (1S1 – 1S2) Core II (2S1 – 2S2) Core III (3S1 – 3S2) Core IV (4S1 – 4S2) iii.

PRIMARY %

20% 40% 80% 20% 40% 80% 20% 40% 80% 20% 40% 80%

HV side B – Phase CORE S1 - S2

Core I (1S1 – 1S2) Core II (2S1 – 2S2)

PRIMARY %

20% 40% 80% 20% 40% 80%

No. CF/SR/02/ R-3 DATED 01/04/2011

Reactor 111

Doc No. D-2-01-03-01-03

Core III (3S1 – 3S2) Core IV (4S1 – 4S2)

20% 40% 80% 20% 40% 80%

Permissible limit of error ± 3% XX.

MAGNETISING CURVES PERFORMANCE

(Not to be done for metering Core) Knee Point Voltage (KVp) = ………………..Volt i.

HV Side R – Phase VOLTAGE TO BE APPLIED

ACTUAL VALUE

0.25 x KVp 0.50 x KVp 0.75 x KVp 1.00 x KVp 1.10 x KVp ii.

UNIT

CORE – I 1S1-1S2


CORE – IV 4S1-4S2

CORE – I 1S1-1S2


CORE – IV 4S1-4S2

CORE – I 1S1-1S2


CORE – IV 4S1-4S2

mA mA mA mA mA

HV Side Y – Phase VOLTAGE

TO BE APPLIED

ACTUAL VALUE

0.25 x KVp 0.50 x KVp 0.75 x KVp 1.00 x KVp 1.10 x KVp iii.

UNIT

mA mA mA mA mA

HV Side B – Phase VOLTAGE

TO BE APPLIED

ACTUAL VALUE


UNIT

mA mA mA mA mA

Note: 1.0 CT should not saturate at 110% of Knee Point Voltage (KVp)

2.0 If Knee Point Voltage is not mentioned then Knee Point Current may be taken into consideration. XXI.

CONTACT RESISTANCE MEASUREMENT at 100 Amps CONTACT RESISTANCE

UNITS

R-Ø

Y-Ø

B-Ø

µ? Across HV Bushing Terminal Joint Across Neutral Bushing terminal joint µ ? µ? NGR terminal connector

The value of Contact Resistance should not be more than 10 Micro – ohms per Joint /Connector 112 Reactor

No. CF/SR/02/ R-3 DATED 01/04/2011

Doc No. D-2-01-03-01-03

XXII.

BUSHING DETAILS STYLE NO / DRAWING NO. R-Ø

Y-Ø

B-Ø

NEUTRAL

NGR

Make Type Sl. No. XXIII.

TAN DELTA AND CAPACITANCE MEASUREMENT OF BUSHING

Make of testing kit

____________________________

Date of calibration

_____________________________

Ambient temperature _____________________________ i.

Capacitance of bushing VOLTAGE APPLIED

R-Ø SITE

Y-Ø

FACTORY

SITE

FACTORY

B-Ø SITE

REMARKS

FACTORY

Measurement of C1 2 KV Measurement of C2 1 KV

ii.

Tan ä of bushings VOLTAGE APPLIED

R-Ø SITE

Y-Ø

FACTORY

SITE

FACTORY

B-Ø SITE

REMARKS

FACTORY

Measurement of C1 2 KV Measurement of C2 Tan ä 1 KV

iii.

Capacitance of NGR bushing

VOLTAGE APPLIED

SITE

FACTORY

2 KV 10 KV iv.

Tan ä of NGR bushings

VOLTAGE APPLIED

SITE

FACTORY

2 KV 10 KV C2 values shall be only for record purpose. Factory test report ref no: *ACCEPTABLE LIMIT FOR Tan ä1:-0.004 & Tan ä2:-0.01 No. CF/SR/02/ R-3 DATED 01/04/2011

Reactor 113

Doc No. D-2-01-03-01-03

XXIV. TAN DELTA AND CAPACITANCE MEASUREMENT OF WINDING

Make of testing kit Date of calibration

____________________________ _____________________________

Ambient temperature _____________________________ VOLTAGE

WINDING COMBINATION

TEST MODE

CAPACITANCE SITE

2 KV 10 KV

TAN DELTA *

FACTORY

SITE

REMARK

FACTORY

UST

HV/Tank+Earh

Factory Test Report Ref. No.: ______________________________________ * Should be comparable (+/- 0.001) with factory value subjected to max of 0.005.

XXV.

VIBRATION MEASUREMENT TEST

i.

Vibration measurements are to be carried out after energization of the reactor. This will be a reference data for future Measurements.

ii.

Various locations are to be shown in the diagram with x,y co-ordinates for easy identification.

SL. NO

DATE OF MEASUREMENT

LOCATION

VALUE

REMARKS

XXVI. PROTECTION AND ALARMS i. DEVICE

SET FOR

SL NO

ALARM

PROVED TRIP

1

EXCESSIVE WINDING TEMPERATURE.

100

110

2

EXCESSIVE OIL TEMPERATUR E.

90

100

114 Reactor

ALARM

TRIP

No. CF/SR/02/ R-3 DATED 01/04/2011

Doc No. D-2-01-03-01-03

3

PRESSURE RELIEF VALVE (MAIN TANK )

NA

NA

4

PRESSURE RELIEF VALVE ( NGR )

NA

NA

5

MAIN TANK BUCHHOLZ RELAY

6

NGR BUCHHOLZ RELAY

7

FAN FAILURE\

NA

NA

8

LOW OIL LEVEL ( MAIN TANK )

NA

NA

9

LOW OIL LEVEL ( NGR )

NA

NA

10

HIGH OIL LEVEL ( MAIN TANK )

NA

NA

11

OTI ( MAIN TANK )

90

100

110

12

OTI ( NGR )

13

WTI ( MAIN TANK )

100

14

DIFFERENTIAL

NA

NA

15

BACKUP IMPEDENCE RELAY

NA

NA

16

EARTH FAULT RELAY ( REF )

NA

NA

17

INTER TRIP , IF ANY

NA

NA

18

TRIP FREE CHECK

NA

NA

19

TEED PROTECTION

ii. Protection setting applied as per engg.approved settings iii. Stability test of differential and REF protection

Yes

No

Remarks

Ok

Not Ok

Remarks

NOTE : Prove the tripping of associ ated breakers by actual

operation of the various

devices and relays as per the schemes. XXVII. FREQUENCY RESPONSE ANALYSIS (FRA)

i.

Carried out after completion of all commissioning activities

ii.

Interpretation of test results carried out

iii.

Test results matching with the factory results

iv.

Factory & site FRA test report available at site

No. CF/SR/02/ R-3 DATED 01/04/2011

Yes

No

Remarks

Yes

No

Remarks

Yes

No

Remarks

Yes

No

Remarks

Reactor 115

Doc No. D-2-01-03-01-03

XXVIII. ALL ELECTRICAL TEST RE SULTS COMPARED WITH FACTORY TEST RESULTS & FOUND TO BE IN ORDER

XXIX.

Yes

No

Remarks

Yes

No

Remarks

No

Remarks

CHECKS AFTER CHARGING OF REACTOR

Record the following after charging i.

Any abnormal sound emanating from the reactor

ii.

No load current at relay terminal

iii.

R-Ø

A

Y-Ø

A

B-Ø

A

Temperature at the time of charging OTI

ºC

WTI

ºC

AMBIENT

ºC

iv.

Maximum temperature after 24 hours____________º C

v.

Thermo vision scanning done at least after 24 hours of loading & repeated one week.

Yes

XXX. FINAL DOCUMENTATION REVIEW

Yes

No

Final documents of Pre- Commissioning checks reviewed and approved

Yes

No

iii.

Document regarding spares equipment, O&M manuals etc available at site for O&M purpose

Yes

No

iv.

After modification, if any, “As built Drawings” are available at site

Yes

No

i.


ii.

Signature:

Signature:

Signature:

Signature:

Name:

Name:

Name:

Name:

Desgn.:

Desgn.:

Desgn.:

Desgn.:


(Erection Agency)



116 Reactor

No. CF/SR/02/ R-3 DATED 01/04/2011

Doc No. D-2-01-03-01-03

PRE-COMMISSIONING FORMATS FOR CIRCUIT BREAKER I.


Region:

Sub-Station:

Feeder Name:

LOA No. :

Make:

Year of Manufacture:

Sr. No.:

Type:

Rating:

Rated Breaking Capacity(kA):

Operating Voltage:

Control Voltage (DC) :

Date of Receipt at site:

Date of Erection:

Date of energisation:


II. SL .NO

1 2 3 4

5 6 7 8 9 10 11 12 13

STATUS

DESCRIPTION YES

REMARKS

NO

Equipment is free from dirt/dust foreign materials etc. Equipment is free from all visible defects on physical inspection Support structures, marshalling box has been provided with double earth All nuts and bolts are tightened correctly as per specified torque Equipment erection is complete in all respect & erection completion certificate along with list of outstanding activities reviewed (attach remaining activities, if any) Permanent pole leveling and identification is done Leveling and alignment of structure and base frame is checked Control box / marshalling kiosk is free from any physical defects Tightness of nuts bolts of terminal connectors are checked Auxiliary contacts and relays have been cleaned and free from rust / damage All spare wires to be kept with ferrules but not terminated at the terminal blocks Check all the valves in the sf6 pipe line are tightened, DILO coupling are tightened. Slow and power closing operation and opening done (wherever applicable)

No. CF/CB/03/ R-3 DATED 01/04/2011

Circuit Breaker 117

Doc No. D-2-01-03-01-03

III.

OPERATING SYSTEM Closing Hydraulic Pneumatic Spring Others

i.

Hydraulic system

a)

Accumulator

Opening Hydraulic Pneumatic Spring Others

R Ø

YØ

BØ

Make Serial number Type Year of manufacture

b)

Pump details

Make Serial number Type Year of manufacturer

c)

Volt Amperes Hp/ kW O/L setting (Thermal Over load)

Details of relays/contactors used

Schematic drawing no______________________ CIRCUIT REFERENCE

MAKE

SERIAL NO.

TYPE

NO+NC

Oil Pressure Monitor Closing Lockout Auto Reclosing Lockout General Lockout Anti Pumping Contactor Pole Discrepancy Timer Auxiliary Power Contactor Others

d)

Operation checks

Date of Hydraulic Oil filling___________ __________ Type of Hydraulic Oil

118 Circuit Breaker

________ _____________

No. CF/CB/03/ R-3 DATED 01/04/2011

Doc No. D-2-01-03-01-03

1. Venting of Hydraulic system SL .NO

ITEM DESCRIPTION

STATUS YES

NO

REMARKS

Pump Pilot Valve Accumulator Hydraulic Mechanism

2. Pressurising hydraulic system SL.NO

DESCRIPTION

1

Pre-filling pressure of N2 in accumulator ( bar / deg. C) Pump running time for charging hydraulic system from initial pressure to working pressure Checking safety valve (open/close) Hydraulic pressure drop for 1 hr Breaker on position Breaker off position Oil pressure monitor Pump on / off bar Pump running time Auto reclosing lockout (oil) Pressure contact _____________ make/break Closing lockout (oil) pressure Contact __________make/break General lockout (oil) Pressure contact __________ make/break Checking anti pumping contactor Pressure contact __________make/break Checking loss of nitrogen Pressure contact __________make/break

2 3 4

5

6 7 8 9 10

FACTORY TEST VALUE

SITE TEST VALUE

REMARK RECORD DEFICIENCIES,IF ANY

Factory test report ref no: ________________________________

3. Oil pressure drop during operations and pump running time in seconds SL.NO (i)

DESCRIPTION

FACTORY TEST VALUE

SITE TEST VALUE

Pressure before operation(Bar) Pressure after closing operation(Bar) Pump running time(Sec)

(ii)

(iii)

(iv)

Pressure before operation(Bar) Pressure after opening operation(Bar) Pump running time(Sec) Pressure before operation(Bar) Pressure after close/open operation (Bar) Pump running time in sec Pressure before operation(Bar) Pressure after open-close-open operation(Bar) Pump running time(Sec)

Factory test report ref no: ________________________________ No. CF/CB/03/ R-3 DATED 01/04/2011

Circuit Breaker 119

Doc No. D-2-01-03-01-03

ii.Pneumatic System a) Operating system details R-Ø

Y-Ø

B-Ø

Remarks

Air receiver no Control block no Pneumatic drive no Magnetic ventil no b) Motor details Make Serial number Type Year of manufacturer c)

Volt Amperes Hp/ kW O/L setting (Thermal Over load)

ICU Details

Make Serial number Type Discharge Capacity Year of manufacturer d) Details of Relays / Contactors used Schematic drawing no__ ____________________ CIRCUIT REFERENCE

MAKE

SERIAL NO.

TYPE

NO+NC

Air Pressure Monitor Closing Lockout Auto Reclosing Lockout General Lockout Pole Discrepancy Timer Auxiliary Power Contactor in ICU Others

e)

Pressure Switch setting CIRCUIT REFERENCE

FACTORY SETTING VALUE BLOCK

DEBLOCK

REMARKS

SITE SETTING VALUE MAKE BLOCK

DEBLOCK

Operation lockout -1 Operation lockout -2 Closing lockout Auto reclosing ckt Low/high pressure Alarm circuit ICU auto setting ICU safety valve Operations

Factory test report ref no: ________________________________ 120 Circuit Breaker

No. CF/CB/03/ R-3 DATED 01/04/2011

Doc No. D-2-01-03-01-03

f)

Pressure drop during operati on : ( in kg/ sq.cm -bar )

SL NO

DESCRIPTION

A

Tripping through TC-I

B

Tripping through TC- II Closing circuit

FACTORY SETTING VALUE

SITE SETTING VALUE

C D

Close-open operation Open - close - open

E

Factory test report ref no: ________________________________ g) Number of operation from local Tank pressure ___________ kg/sq.cm or bar BREAKER INITIALLY CLOSE : FACTORY TEST :

O-C-

SITE TEST :

O-C-

PLEASE KEEP INLET PNEUMATIC VALVE CLOSED IN THESE OPERATION

BREAKER INITIALLY OPEN : FACTORY TEST :

C-O-

SITE TEST :

C-O-

PLEASE KEEP INLET PNEUMATIC VALVE CLOSED IN THESE OPERATION

h) Air pressure drop in 24 hrs DROP IN PRESSURE IN KG/SQ.CM OR BAR BREAKER ON BREAKER OFF

iii.SPRING OPERATING

SYSTEM

a) Motor details Make

Volt

Sl no Type

Amperes Hp/kw

Year of Manufacture Dc current taken by motor for charging the spring ( amp) No. CF/CB/03/ R-3 DATED 01/04/2011

Setting (thermal overload)

Circuit Breaker 121

Doc No. D-2-01-03-01-03

b) Details of relays/contactors used : schematic drawing no CIRCUIT REFERENCE

MAKE

SERIAL NO.

TYPE

NO+NC

Closing lockout Auto reclosing lockout General lockout Pole descrepancy timer Auxillary Power contactor Others c)

Spring operating time R-PHASE

DETAILS

FACTORY

Y-PHASE SITE

FACTORY

B-PHASE SITE

FACTORY

SITE

CHARGING TIME

Factory test report ref no

IV.

SF6 DENSITY MONITOR DETAILS

i.

RPHASE

Y-PHASE

BPHASE

Make Model Sl.no Year of manufacture Quantity of SF6 gas filled actual

B:

As per Specification ii.

SF6 density monitor settings

SF6 gas

filled at ________ bar at _____ deg. C on ___/___/___ DETAILS

BLOCKING

DEBLOCKING

PHASE FACTORY R - PHASE

REFILL ALARM OPERATION BLOCK

Y - PHASE


B - PHASE


Factory test report ref no 122 Circuit Breaker

SITE

FACTORY

SITE

:

No. CF/CB/03/ R-3 DATED 01/04/2011

Doc No. D-2-01-03-01-03

iii.

Measurement of dew point of sf6 gas MEASURED VALUE

SL. NO

PERMISSIBLE LIMITS TO BE DECIDED AS PER GRAPH

Dew point measurement of SF6 gas needs to be done pole wise in close loop method without any wastage of SF6 gas NOTE:

iv.

Leakage check SL.NO

A B

INTERVALS

Initial filling of sf6 gas at ____deg c (As per temp. Correction chart )

C

Drop in sf6 gas pressure in 24 hrs : Final sf6 pressure at ________deg. C After all testing

D

Additional leakage test by covering individual joint with polythene

UNIT BAR BAR

BAR YES

No. CF/CB/03/ R-3 DATED 01/04/2011

NO

Circuit Breaker 123

Doc No. D-2-01-03-01-03

V.

COIL RESISTANCE MEASUREMENT SL NO

PHASE

A

R

B

Y

C

VI.

B

COIL

UNIT

TRIP COIL - I

?

TRIP COIL - II

?

CLOSE COIL

?

TRIP COIL - I

?

TRIP COIL - II

?

CLOSE COIL

?

TRIP COIL - I

?

TRIP COIL - II

?

CLOSE COIL

?

SERIES RESISTOR

MEASURED VALUE

TOTAL

CIRCUITRY / OPERATIONAL CHECKS CIRCUITARY CHECK SL NO

OPERATIONAL CHECK

CIRCUIT REFERENCE LOCAL

A

TRIPPING THROUGH TC-I

B

TRIPPING THROUGH TC-II

C

CLOSING CIRCUIT

D

ANTI-HUNTING FEATURE

REMOTE

LOCAL

REMOTE

(CLOSE OPEN OPERATION ) E

POLE DISCREPANCY FEATURE

F

BREAKER POSITION INDICATION

G

HEATER IN SWITCH CUBICLE

H

HEATER IN CONTROL CUBICLE

I

ILLUM. IN SWITCH CUBICLE

J

ILLUM. IN CONTROL CUBICLE

;

Note: In case wiring for remote operation is not ready, please indicate terminal number along with wire ferrule number in switch cubicle where remote cables shall be terminated. Remote operation can be checked from these terminals

VII.

OPERATING TIME ( IN MILLI-SECONDS )

PHASE

BREAK

CLOSE (Max 150 ms)

T R I P (Max 25 ms 400kV,35 ms 220kV, 40 ms 132 kV) TRIP - I

R - ph main contact R - PH PIR ( 12 ± 4 ms) Auxiliary contact R - ph main contact R - PH PIR ( 12 ± 4 ms) Auxiliary contact Y - ph main contact Y - PH PIR ( 12 ± 4 ms) Auxiliary contact

124 Circuit Breaker

CLOSE TRIP (Min. 35 ms)

TRIP - II

TRIP - I

TRIP - II

BREAK 1

BREAK 2

BREAK 1

No. CF/CB/03/ R-3 DATED 01/04/2011

Doc No. D-2-01-03-01-03

Y - ph main contact Y - PH PIR ( 12 ± 4 ms) Auxiliary contact B - ph main contact B - PH PIR ( 12 ± 4 ms) Auxiliary contact B - ph main contact B - PH PIR ( 12 ± 4 ms) Auxiliary contact

BREAK 2

BREAK 1

BREAK 2

NOTE: for 765 kV, take measur ements for four breaks VIII.

IR VALUE OF CONTROL CIRCUIT(USING 500 VOLT MEGGER) COIL DETAILS

UNIT

R – PHASE TRIP COIL - I

MEASUREMENT VALUE

M? M?

R – PHASE TRIP COIL - II

M?

R – PHASE CLOSE COIL

M?

Y – PHASE TRIP COIL - I

M?

Y – PHASE TRIP COIL - II

M?

Y – PHASE CLOSE COIL

M?

B – PHASE TRIP COIL - I

M?

B – PHASE TRIP COIL - II

M?

B – PHASE CLOSE COIL

CAUTION: Isolate necessary dc for trip coil i and trip coil ii ,closing coil before meggaring. MINIMUM VALUE 2 MOHM IX.

IR VALUE WITH BREAKER OP EN(USING 5000 VOLT MEGGER) ACROSS OPEN CONTACT

UNIT

MEASUREMENT VALUE

M?

R - PHASE BREAK 1

M?

R - PHASE BREAK-2

M?

Y - PHASE BREAK 1

M?

Y - PHASE BREAK-2

M?

B - PHASE BREAK 1

M?

B - PHASE BREAK-2

MINIMUM VALUE 2 MOHM X.

IR VALUE WITH RESPECT TO EARTH WITH BREAKER CLOSED, EARTH SWITCH AND ISOLATOR OPEN BETWEEN R – PHASE AND EARTH Y – PHASE AND EARTH B – PHASE AND EARTH

No. CF/CB/03/ R-3 DATED 01/04/2011

UNIT

MEASUREMENT VALUE

M? M? M?

Circuit Breaker 125

Doc No. D-2-01-03-01-03

XI.

MINIMUM PICKUP VOLTAGE OF COILS UNIT

COIL DETAILS R – PHASE TRIP COIL - I

M? M?

R – PHASE TRIP COIL - II

M?

R – PHASE CLOSE COIL

M?

Y – PHASE TRIP COIL - I

M?

Y – PHASE TRIP COIL - II

M?

Y – PHASE CLOSE COIL

M?

B – PHASE TRIP COIL - I

M?

B – PHASE TRIP COIL - II

M?

B – PHASE CLOSE COIL

XII.

MEASUREMENT VALUE

GRADING CAPACITOR i.

DETAILS INTERRUPTER 1

INTERRUPTER 2

DETAILS R

Y

B

R

Y

B

MAKE SERIAL NO. CAPACITANCE VALUE FACTORY VALUE YEAR OF MANUFAC.

ii.

CAPACITANCE AND TAN DELTA MEASUREM ENT (TO BE DONE IN UST MODE) INTERRUPTER 1

INTERRUPTER 2

CAPACITANCE R

Y

B

R

Y

B

SITE -FACTORY % DEVIATION TAN DELTA SITE -FACTORY % DEVIATION

Permissible Limits a) Tan delta of grading capacitors 0.007 (max.) b) Rate of rise in Tan Delta 0.001 per year (max) c) Capacitance of grading capacitors within ±5% of the rated value Note: a) Since temperature correction factor for Tan-Delta depends on make, type and also aging conditions, the correction factors for different types / makes are different. Hence, no standard temperature correction factors can be applied.

b) In case of violation of Tan-Delta the test results with temperature are to be referred to CC/OS 126 Circuit Breaker

No. CF/CB/03/ R-3 DATED 01/04/2011

Doc No. D-2-01-03-01-03

XIII.

CONTACT RESISTANCE MEASUREMENT SL.NO

PHASE

A

R-PHASE

B

Y-PHASE

C

B-PHASE

ACROSS EACH POLE

ACROSS INTERRUPTR 1

FACTORY

FACTORY

SITE

a) Contact Resistance of CB (in Micro-Ohm)

ACROSS INTERRUPTER 2

SITE

400kV 150 ì? *

FACTORY

220kV 100 ì?

SITE

132kV 100 ì?

* 75 ì? (Micro-Ohm) per break b) Contact Resistance of CB terminal connector 10 Micro-Ohm per connector

Factory test report ref no :______________________ XIV.

BREAKER OPERATION COUNTER READING COUNTER TYPE ELECTRICAL MECHANICAL

SL.NO

XV.

SL NO

PHASE

A

R-PHASE

B

Y-PHASE

C

B--PHASE

DESCRIPTION OF TEST

Switch off the dc switch in Control cubicle

B

Switch off the ac Switch in control Cubicle Short the alarm contacts of sf6 Gas density monitor (R-phase) Short the alarm contacts of sf6 Gas density monitor (Y-pha se) Short the alarm contacts of sf6 Gas density monitor (B-phase) Remove the cable connected to density monitor (R-phase)

D E F

G

H

DATE

CHECK FOR ANNUNCIATION IN CONTROL ROOM AS PER THE FOLLOWING FORMATS AND RECORD THE READING

A

C

READING

SOURCE OF INITIATION

Control cubicle dc Switch on/off Control cubicle ac Switch on/off

Density monitor

Operation/closi ng lockout

Density monitor

Operation/closi ng lockout

Density monitor

Operation/closi ng lock out

Remove the cable connected to density monitor (B-phase)

OK

NOT OK

REMARK

Source I/II dc fail / ac fail

Density monitor

Density monitor

Remove the cable connected to density monitor (Y-phase)

No. CF/CB/03/ R-3 DATED 01/04/2011

DESCRIPTION

Source I/II dc fail / ac fail Sf6 gas density low Sf6 gas density low Sf6 gas density low

Density monitor

RESULT

WINDOW

Circuit Breaker 127

Doc No. D-2-01-03-01-03

Give tripping command to R-ph only and check the operation of pole discrepancy relay Give tripping command to Y-ph Only and check the operation of pole discrepancy relay

I

J K

Give tripping Command to B-ph only and check the operation of pole discrepancy relay

Pole discrepancy relay at breaker Cubicle

Pole discrepancy relay at breaker Cubicle pole discrepancy relay at breaker cubicle

Breaker pole discrepancy

Breaker pole discrepancy Breaker pole discrepancy

L Check other alarms as per plant Circuit diagram Close the breaker and trip through Protection which are applicable

M

protection relay as per scheme

Breaker auto trip

NOTE : The tripping details are to be checked as per the Scheme approved by

engineering. XVI.

DYNAMIC CONTACT RESISTANC E & TRAVEL MEASUREMENT PHASE

FACTORY

SITE

APPROVAL FROM CC/OS OBTAINED

REMARKS

R Y B

XVII. OPERATION TIME MEASUREMENT OF POLE DISCREPANCY RELAY Close/Trip time pole discrepancy at rated operating pressure a) Phase to Phase (Max) - close operation

Permissible Limits 5.0ms 3.33ms 2.5 ms

b) Phase to Phase (Max) - open operation c) Break to Break (Max) of same pole

Note- 2.5 Sec for CBs with Auto Reclose Function & 0.5 Sec for CBs without Auto Reclose Function.

XVIII. MECHANICAL CLOSE INTERLOCK CHECKED (WHEREVER APPLICABLE) XIX.

Yes

No

Yes

No

FINAL DOCUMENTATION REVIEW

i.


ii.


Yes

No

iii.

Document regarding spares equipment, O&M manuals etc available at sit for O&M purpose

Yes

No

128 Circuit Breaker

No. CF/CB/03/ R-3 DATED 01/04/2011

Doc No. D-2-01-03-01-03

iv.


v.

CC-OS approved dcrm signatures available

Yes

No

Yes

No

Signature:

Signature:

Signature:

Signature:

Name:

Name:

Name:

Name:

Designation:

Designation:

Designation:

Designation:


(Erection Agency)



No. CF/CB/03/ R-3 DATED 01/04/2011

Circuit Breaker 129

Doc No. D-2-01-03-01-03

PRE-COMMISSIONING FORMATS FOR CURRENT TRANSFORMER I.


Region:

Sub-Station:

LOA No. :

Make:

Sr. No.: RØ:YØ:BØ:Year of Manufacture: R Ø:YØ:BØ:Date of Receipt at site: RØ:YØ:B Ø:Date of energisation (To be written after commissioning)

Type:

II.

Rating:

Date of Erection: RØ:YØ:BØ:-

RATED DATA AND DUTY CORE

Winding Winding Winding Winding Winding

RATIO

CLASS

BURDEN

Kvp

PROTECTION / METERING

I II III IV V

KVp : Knee Point Voltage In Volts III.

PRE-COMMISSIONING CHECKS: STATUS

SL. NO

1 2

DESCRIPTION YES

NO

REMARKS RECORD DEFICIENCIES, IF ANY

Equipment is cleaned and free from dust / dirt foreign materials etc. Equipment is free from all visible defects on physical inspection

130 Current Transformer

No. CF/CT/04/ R-3 DATED 01/04/2011

Doc No. D-2-01-03-01-03

SL. NO

3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29

DESCRIPTION

STATUS YES

NO

REMARKS RECORD DEFICIENCIES, IF ANY

Check CT tank has been provided with double earthing (dead tank CT's) Check that CT junction box is earthed. All nuts and bolts are tightened correctly as per specified torque Check tightness of terminal connector All fittings as per out line general arrangement drawing. Leveling and alignment of structure and base frame is checked Erection completion certificate along with list of outstanding activities reviewed Any paint removed / scratched in transit has been touched up Check primary polarity of CTs erected as per relevant drawing. Check hermetically sealing is intact Check the oil level and leakage through any joints / sec. Terminals Check oil drain valve is properly closed and locked. N2 pressure checked (wherever applicable) Oil level on top chamber gauge glass Oil sample taken for BDV and PPM measurement from tank bottom drain valve ( only if Nitrogen pressure is measured zero ) All the cable identification tags provided and all cores are provided with identification ferrules at MB. Check secondary cable end box is properly fixed and ensure cable entry at the bottom and unused holes sealed Ensure interpole cabling is completed and check the continuity. Check the ir value of secondary cable Check external cabling from junction- box to relay / control panel completed Ensure unused secondary cores, if any, has been shorted Check star point has been formed properly and grounded at one end only Check spark gap setting in P1 terminal (wherever provided/ possible) permanent Pole leveling and identification markings made Check tan delta test tap is properly earthed Check that lugs used in secondary circuit are of ring type Check direction of primary (P1/ P2) w.r.t. Bus/ line on erection Provision of bimetallic strips (Cu+Al) ensured wherever applicable

No. CF/CT/04/ R-3 DATED 01/04/2011

Current Transformer 131

Doc No. D-2-01-03-01-03

IV.


a)

Insulation Resistance Measurement (Using 5000Volt Megger) Make & Sl. No of testing kit _____________________ Date of last calibration of kit _____________________ Ambient temp in º C

_____________________

Remove the connected earthing to system involving CT under test and disconnect the connected terminals of ct marshalling box PHASE CORE PRIMARY - CORE I PRIMARY - CORE II PRIMARY - CORE III PRIMARY - CORE IV PRIMARY - CORE V PRIMARY - EARTH

UNIT M M M M M M

RØ

YØ

BØ

? ? ? ? ? ?

* Permissible limit of IR value should be > 1000 M?

b)

Insulation Resistance Measurement in M? (Using 500 V Megger) Make & Sl. No of testing kit _____________________ Date of last calibration of kit _____________________ Ambient temp in º C

_____________________

RØ

SECONDARY CORE I - EARTH

SECONDARY CORE IV - EARTH SECONDARY CORE V - EARTH

CORE I - CORE III


BØ

M? M? M? M?

SECONDARY CORE III - EARTH

CORE I - CORE II

YØ

M?

SECONDARY CORE II - EARTH

BETWEEN

PHASE

UNIT

BETWEEN

PHASE

UNIT RØ

YØ

BØ

M? M?

No. CF/CT/04/ R-3 DATED 01/04/2011

Doc No. D-2-01-03-01-03

M? M? M? M? M? M? M? M?

CORE I - CORE IV CORE I - CORE V CORE II - CORE III CORE II - CORE IV CORE II - CORE V CORE III - CORE IV CORE III- CORE V CORE IV - CORE V

*Permissible limit of IR value should be > 50 M ?

c)

Check IR value between tan delta point and earth at 1 kV in secondary box RØ

V.

YØ

BØ

MEASUREMENT OF SECONDARY WINDI NG RESISTANCE (IN OHM)

Make of testing kit

___________________ Date of calibration______________

Ambient temperature __________________

CORE

TERMINAL

CORE I

1S1 - 1S2 1S1 - 1S3 1S1 - 1S4

CORE II

2S1 - 2S2 2S1 - 2S3 2S1 - 2S4

CORE III

3S1 - 3S2 3S1 - 3S3 3S1 - 3S4

CORE IV

4S1 - 4S2 4S1 - 4S3 4S1 - 4S4

CORE V

5S1 - 5S2 5S1 - 5S3 5S1 - 5S4

UNIT

RØ FACTORY

SITE

YØ FACTORY

BØ FACTORY

SITE

SITE

? ? ? ? ? ? ? ? ? ? ? ? ? ? ?

Factory test report ref.no:________________________________ VI.

POLARITY TEST (WITH 1.5 VOLT DC SUPPLY)

Connect +ve at P1 and –ve at P2 PHASE CORE

BETWEEN R -PHASE

CORE I

1S1 (+VE)

No. CF/CT/04/ R-3 DATED 01/04/2011

Y -PHASE

B -PHASE

1S2 (-VE)


Doc No. D-2-01-03-01-03

1S1 (+VE)

CORE II

CORE III

CORE IV

CORE V

VII.

1S3 (-VE)

1S1 (+VE)

1S4 (-VE)

2S1 (+VE)

2S2 (-VE)

2S1 (+VE)

2S3(-VE)

2S1 (+VE)

2S4 (-VE)

3S1 (+VE)

3S2(-VE)

3S1 (+VE)

3S3(-VE)

3S1 (+VE)

3S4(-VE)

4S1 (+VE)

4S2(-VE)

4S1 (+VE)

4S3(-VE)

4S1 (+VE)

4S4(-VE)

5S1 (+VE)

5S2(-VE)

5S1 (+VE)

5S3(-VE)

5S1 (+VE)

5S4(-VE)

TAN DELTA AND CAPACITANCE MEASUREMENT

Make of testing kit

______________________________

Date of calibration

_____________________________

Ambient temperature __ ___________________________ CAPACITANCE

ACROSS STACK

PRE COMMISSIONING VALUES R Ø

YØ

B Ø

FACTORY VALUES R Ø

YØ

B Ø

% DEVIATION FROM FACTORY VALUES R Ø YØ B Ø

2kV 10 kV TAN DELTA

ACROSS STACK

PRE COMMISSIONING VALUES R Ø

YØ

B Ø

FACTORY VALUES R Ø

YØ

B Ø

% DEVIATION FROM FACTORY VALUES R Ø YØ B Ø

2kV 10 kV Permissible Limits Tan ä 0.007 (max.) and Rate of rise in Tan Delta 0.001 per year (max) Deviation of Capacitance value from factory value should be within ± 5% of the rated value 1-Since temperature correction factor for Tan-Delta depe nds on make, type and also aging conditions, the correction factors for different types / makes are different. Hence, no standard temperature correction factors can be applied. 2- In case of violation of Tan- Delta the test results with temperature are to be referred to CC/OS FACTORY TEST REPORT REF. NO:____________________________________________

VIII.

CURRENT RATIO TEST

Make of testing kit

________________________________________

Date of calibration

_______________________________________


No. CF/CT/04/ R-3 DATED 01/04/2011

Doc No. D-2-01-03-01-03

Primary Injection through Primary Injection Kit at Primary Terminal P1 – P2. Measure the current on the secondary Terminals R PHASECORE S1 - S2

PRIMARY CURRENT %

ACTUAL

SECONDARY CURRENT

THEORETICAL RATIO

ACTUAL RATIO

% OF ERROR

20 % CORE I (1S1 - 1S2)

40 % 80 % 20 %

CORE II (2S1 - 2S2)

40 % 80 % 20 %

CORE III (3S1 - 3S2)

40 % 80 % 20 %

CORE IV (4S1 - 4S2)

40 % 80 % 20 %

CORE V (5S1 - 5S2)

40 % 80 % 20 %

CORE I (1S1 - 1S3)

40 % 80 % 20 %

CORE II (2S1 - 2S3)

40 % 80 % 20 %


40 % 80 % 20 %

CORE IV (4S1 - 4S3)

40 % 80 % 20 %

CORE V (5S1 - 5S3)

40 % 80 % 20 %

CORE I (1S1 - 1S4)

40 % 80 % 20 %

CORE II (2S1 - 2S4)

40 % 80 % 20 %


40 % 80 %

CORE IV (4S1 - 4S4)

20 % 40 %

No. CF/CT/04/ R-3 DATED 01/04/2011


Doc No. D-2-01-03-01-03

80 % 20 % CORE V (5S1 - 5S4)

40 % 80 %

Y PHASECORE S1 - S2

PRIMARY CURRENT %

ACTUAL

SECONDARY CURRENT

THEORETICAL RATIO

ACTUAL RATIO

% OF ERROR

20 % CORE I (1S1 - 1S2)

40 % 80 % 20 %

CORE II (2S1 - 2S2)

40 % 80 % 20 %


40 % 80 % 20 %

CORE IV (4S1 - 4S2)

40 % 80 % 20 %

CORE V (5S1 - 5S2)

40 % 80 % 20 %

CORE I (1S1 - 1S3)

40 % 80 % 20 %

CORE II (2S1 - 2S3)

40 % 80 % 20 %


40 % 80 % 20 %

CORE IV (4S1 - 4S3)

40 % 80 % 20 %

CORE V (5S1 - 5S3)

40 % 80 % 20 %

CORE I (1S1 - 1S4)

40 % 80 % 20 %

CORE II (2S1 - 2S4)

40 % 80 %


20 % 40 %


No. CF/CT/04/ R-3 DATED 01/04/2011

Doc No. D-2-01-03-01-03

80 % 20 % CORE IV (4S1 - 4S4)

40 % 80 % 20 %

CORE V (5S1 - 5S4)

40 % 80 %

B PHASE:CORE S1 - S2

PRIMARY CURRENT %

ACTUAL

SECONDARY CURRENT

THEORETICAL RATIO

ACTUAL RATIO

% OF ERROR

20 % CORE I (1S1 - 1S2)

40 % 80 % 20 %

CORE II (2S1 - 2S2)

40 % 80 % 20 %


40 % 80 % 20 %

CORE IV (4S1 - 4S2)

40 % 80 % 20 %

CORE V (5S1 - 5S2)

40 % 80 % 20 %

CORE I (1S1 - 1S3)

40 % 80 % 20 %

CORE II (2S1 - 2S3)

40 % 80 % 20 %


40 % 80 % 20 %

CORE IV (4S1 - 4S3)

40 % 80 % 20 %

CORE V (5S1 - 5S3)

40 % 80 % 20 %

CORE I (1S1 - 1S4)

40 % 80 %

CORE II (2S1 - 2S4)

20 % 40 %

No. CF/CT/04/ R-3 DATED 01/04/2011


Doc No. D-2-01-03-01-03

80 % 20 % CORE III (3S1 - 3S4)

40 % 80 % 20 %

CORE IV (4S1 - 4S4)

40 % 80 % 20 %

CORE V (5S1 - 5S4)

40 % 80 %

Note:During ratio test of CT,the current level attained should not be less than 500A) Permissible Limit for protection core ± 3% and for metering core ± 1% IX.

MAGNETISING CURVE PERFORMANCE

Knee Point Voltage (KVp) = ………………..Volt R – Phase VOLTAGE TO BE APPLIED

ACTUAL VALUE


UNIT

CORE – I 1S1-1S2


CORE – IV 5S1-5S2

CORE – I 1S1-1S2


CORE – IV 5S1-5S2

CORE – I 1S1-1S2


CORE – IV 5S1-5S2

mA mA mA mA mA

Y-Phase VOLTAGE TO BE APPLIED

ACTUAL VALUE

UNIT

mA mA mA mA mA


B-Phase VOLTAGE TO BE APPLIED

0.25 x KVp 0.50 x KVp 0.75 x KVp 1.00 x KVp 1.10 x KVp 138 Current Transformer

ACTUAL VALUE

UNIT

mA mA mA mA mA No. CF/CT/04/ R-3 DATED 01/04/2011

Doc No. D-2-01-03-01-03

X.

CONTACT RESISTANCE MEASUREMENT


____________________________ _____________________________

CONTACT RESISTANCE

Across Terminal P1 Across Terminal P2

UNITS

R-Ø

Y-Ø

B-Ø

µ? µ?

The value of Contact Resi stance should not be more than 10 Micro – ohms per Joint / Connector XI.

DISSOLVED GAS ANALYSIS

DISSOLVED GASES

H2 CH4 CO CO2 C2H4 C2H6 C2H2 O2 N2 TCG

XII.


i.


Yes

No

ii.


Yes

No

Yes

No

iii. After modification, if any, “As built Drawings” are available at site

Signature:

Signature:

Signature:

Signature:

Name:

Name:

Name:

Name:

Designation:

Designation:

Designation:

Designation:




No. CF/CT/04/ R-3 DATED 01/04/2011


Doc No. D-2-01-03-01-03

PRE-COMMISSIONING FORMATS FOR CAPACITIVE VOLTAGE TRANSFORMER GENERAL DETAILS

I.

DETAILS Sub-Station:

Region: Feeder name

LOA No. :

Make: Sr. No.: RØ:YØ:BØ:Secondary Voltage rating: Winding-I Winding-II Winding III Voltage Class: Winding-I Winding-II Winding III Rating:

Type: Primary Voltage rating

Secondary Voltage Burden: Winding-I Winding-II Winding III Purpose of Winding-I Winding-II Winding III Feeder name:

Year of Manufacture: RØ:YØ:BØ:Date of Erection: RØ:YØ:BØ:-

Date of Receipt at site: R Ø:YØ:BØ:Date of energisation


II.

STATUS SL. NO

DESCRIPTION YES

2

Equipment is cleaned and free from dust / dirt foreign materials etc. Equipment is free from all visible defects on physical inspection

3

Check CVT tank has been provided with double earthing

4

Check that CVT marshalling box is earthed All nuts and bolts are tightened correctly as per specified torque

1

5

140 Capacitive Voltage Transformer

REMARKS (RECORD DEFICIENCIES, IF ANY)

NO

No. CF/CVT/05/ R-3 DATED 01/04/2011

Doc No. D-2-01-03-01-03

6

Check tightness of terminal connector

7

All fittings as per outline general arrangement drawing.

8

14

Leveling and identification marking is carried out Leveling and alignment of structure and base frame is checked Erection completion certificate along with list of outstanding activities reviewed Any paint removed / scratched in transit has been touched up Sl. No of HV capacitor identical to the sl.no mentioned on rating & dig. Plate Ensure brass vent plug between stacks of CVT's is removed Check the oil level and leakage through any joints / sec. Terminals

15

Check oil drain valve is properly closed and locked.

16

Oil level on tank gauge glass

17

BDV of oil sample taken from tank bottom drain valve Check secondary cable end box is properly fixed and ensure cable entry at the bottom. Ensure HF terminal of unused phases has been earthed and no load on HF terminal bushing Check rating / healthiness of fuses at CVT marshaling.box and CVT terminal box.

9 10 11 12 13

18 19 20 21 22 23 24 25

III.

Check that the neutral point is earthed Ensure interpole cabling is completed and check the continuity. Check the ir value of secondary cable ( > 50 m ohms for control cables) Check external cabling from m.b to relay / control panel completed All the cable identification tags provided and all cores are provided with identification ferrules at m.b.

CONTINUITY OF WINDING (After removing Earth Link 1,2 & 3)

i.

Between terminals 1a - 1n

ii.


iii.


No. CF/CVT/05/ R-3 DATED 01/04/2011

OK

NOT OK

OK

NOT OK

OK

NOT OK

Capacitive Voltage Transformer 141

Doc No. D-2-01-03-01-03

IV.


Using a megger Of 5kV/ 10 kV MEASURED VALUE

BETWEEN UNIT R Ø

YØ

BØ

M? M? M? M?

Primary - secondary core 1 Primary - secondary core 2 Primary - secondary core 3 Primary - earth

Permissible Limit should be min 1000 M? SECONDARY WINDING RESISTANCE

V.

CORE 1

CORE 2

CORE 3 REMARKS

PHASE FACTORY

SITE

FACTORY

SITE

FACTORY

SITE

R Ø YØ BØ

Factory test report ref. No : _______________________________________________ INSULATION RESISTANCE MEASUREMENT

VI.

(Using a megger of 500 volt) MEASURED VALUE

BETWEEN UNIT

Secondary core 1 - earth Secondary core 2 - earth Secondary core 3 - earth Core 1 - core 2 Core 1 - core 3 Core 2 - core 3

R Ø

YØ

BØ

M? M? M? M? M? M?

Permissible Limit should be MIN 50 M? VOLTAGE RATIO TEST

VII.

SECONDARY VOLTAGE PHASE

R

PRIMARY VOLTAGE

BETWEEN

VALUE

THEORETICAL RATIO

ACTUAL RATIO FACTORY

SITE

% ERROR

1a – 1 n 2a – 2 n 3a – 3 n


No. CF/CVT/05/ R-3 DATED 01/04/2011

Doc No. D-2-01-03-01-03

1a – 1 n 2a – 2 n 3a – 3 n 1a – 1 n 2a – 2 n 3a – 3 n

Y

B

Permissible Limit should be min ± 5 % for protection cores and ± 0.5 % for metering cores

Note:a) Apply voltage of the order of 500v or more across line capacitor ( top flange ) to earth link b) Ensure all earth links connected VIII.

i.

All terminal blocks closed in the secondary after all testing

ii.

Phasing ( phase relationship ) of CVT by measuring voltage between R-phase, Yphase and B-phase at incoming terminal in control cubicle, for one circuit of the checked CVT and output terninals R-phase, Y- phase and B-ph of a reference circuit (existing CVT) with known phasing REFERENCE CIRCUIT

Yes

No

MEASURED VALUE RØ

YØ

BØ

R-PHASE Y-PHASE B-PHASE

Note: Permissible Limits for CVTs used for purp oses other than metering. For CVTs used for commercial metering accuracy class limits to be followed. DRIFT IN SECONDARY VOLTAGE (TO BE MEASURED BY 0.2 / 0.5 CLASS MULTIMETER)

a) Upto ± 0.5 volts b) + 0.5 to +0.8 volts c) +0.8 to +1.2 volts d) +1.2 to +2.0 volts e) Above +2.0 volts f) -0.8 to -4.0 volts g) Less than -4.0 volts IX.

CONDITION

Healthy To be monitored Close monitoring Close monitoring Alarming Close monitoring Alarming

MEASUREMENT FREQUENCY

6 monthly 3 monthly monthly 15 days replacement 15 days replacement

TAN DELTA AND CAPACITANCE MEASUREMENT

Make of t esting kit

_______________________________

Date of calibration

______________________________

Ambient temperature _____________________________ No. CF/CVT/05/ R-3 DATED 01/04/2011

Capacitive Voltage Transformer 143

Doc No. D-2-01-03-01-03

CAPACITANCE PRE COMMISSIONING VALUES

FACTORY VALUES

% DEVIATION

ACROSS STACK RØ

YØ

BØ

RØ

YØ

B Ø

R Ø

YØ

B Ø

TOP MIDDLE BOTTOM TOTAL TAN DELTA PRE COMMISSIONING VALUES

FACTORY VALUES

% DEVIATION

ACROSS STACK RØ

YØ

BØ

RØ

YØ

BØ

RØ

YØ

BØ

TOP MIDDLE BOTTOM TOTAL

Permissible Limits Tan ä 0.007 (max.) and Rate of rise in Tan Delta 0.001 per year (max) Deviation of Capacitance value from factory value should be within ± 5% of the rated value 1-Since temperature correction factor for Tan-Delta depe nds on make, type and also aging conditions, the correction factors for different types / makes are different. Hence, no standard temperature correction factors can be applied. 2- In case of violation of Tan- Delta the test results with temperature are to be referred to CC/OS FACTORY TEST REPORT REF. NO:______________________________

X.


i.


Yes

No

ii.


Yes

No

iii.


Yes

No

Signature:

Signature:

Signature:

Signature:

Name:

Name:

Name:

Name:

Designation:

Designation:

Designation:

Designation:


(Erection Agency)


(POWERGRID


Members:

No. CF/CVT/05/ R-3 DATED 01/04/2011

Doc No. D-2-01-03-01-03

PRE-COMMISSIONING FORMATS FOR BAY/FEEDER I.


Region

Sub-Station

Feeder Name

Voltage Level

Date of Starting of Erection

Date of Completion of Erection and Oil filling

II.

DETAILS OF EQUIPMENT INVOLVED R - PHASE EQUIPMENT

Y - PHASE

B - PHASE MAKE

ID NO

SL NO

ID NO

SL NO

ID NO

SL NO

CT

CVT

LA

BREAKER

TRANSFORMER REACTOR

ISOLATOR

EARTH SWITCH

LINE TRAP

No. CF/BAY/06/ R-3 DATED 01/04/2011

Bay/Feeder 145

Doc No. D-2-01-03-01-03

III.

DETAILS OF CR PANEL AND PLCC PANEL DETAILS

IDENTIFICATION NAME

IDENTIFICATION

NUMBER

NAME

NUMBER

IDENTIFICATION NAME

MAKE

NUMBER

Control Panel Relay Panel PLCC Panel RTU Panel

RECORDING INSTRUMENTS

IDENTIFICATION NAME

NUMBER

Fault Locator Event Logger Disturbance Recorder Time Syncronisation Strip Chart Recorder IV.

PROTOCOL DOCUMENTATION

EQUIPMENT

IDENTIFI CATION NO

ALL PRECOMM TESTS CARRIED OUT AS PER FQP YES/ NO

ALL TEST RESULTS ARE WITHIN THE LIMIT OF TOLERANCE YES/ NO

JOINT PROTOCOLS OF THE EQUIPMENT INVOLVED IN CHARGING ARE DOCUMENTED AND SIGNED BY ALL CONCERNED YES/NO

REMARKS

CT

CVT

LA

BREAKER TRANSFORMER REACTOR

ISOLATOR

146 Bay/Feeder

No. CF/BAY/06/ R-3 DATED 01/04/2011

Doc No. D-2-01-03-01-03

EQUIPMENT

IDENTIFI CATION NO

ALL PRECOMM TESTS CARRIED OUT AS PER FQP YES/ NO

ALL TEST RESULTS ARE WITHIN THE LIMIT OF TOLERANCE YES/ NO

JOINT PROTOCOLS OF THE EQUIPMENT INVOLVED IN CHARGING ARE DOCUMENTED AND SIGNED BY ALL CONCERNED YES/NO

REMARKS

EARTH SWITCH

LINE TRAP

CONTROL PANEL

RELAY PANEL

PLCC

RTU PANEL

No. CF/BAY/06/ R-3 DATED 01/04/2011

Bay/Feeder 147

Doc No. D-2-01-03-01-03

V.

CHECK OF BAY MARSHALLING KIOSK Identification No_____________ STATUS

DETAILS OK/NOT OK ILLUMINATION

OK/NOT OK

REMARKS, IF ANY OK/NOT OK

AND HEATER

5 /15 AMP SOCKET ALL SPECIFIED FUSES IN POSITION EARTHING AT 2 LOCATI ON ALL CABLES TIGHTNESS ALL CABLES ARE PROPER LY GLANDED ALL CABLES HAVE IDENTIFICATION NO ALL CORES HAVE IDENTIFICATION NO SHIELDING WIRES ARE EARTHED FREE FROM DUST AND DAMAGE DOOR HINGES AND LOCKING PAINTS UNUSED HOLES ARE SEALED

VI.

AVAILABILITY OF THE FOLLOWING STATUS

SL. NO.

DESCRIPTION OF ACTIVITY YES

1

Fire fighting system commissioned

2

Fire protection including alarms

3

Fire hydrant system

4

Fire deluge (spinkler) system

5

Portable fire extinguishers are in position

6

Fire tenders can be made available for any eventuality All equipment erection as per general arrangement drawing issued by engg. Equipment identification name plate are properly fixed All bus post insulators are cleaned and free from dust / dirt foreign materials etc. All earthing points have been earthed

7 8 9 10 11 12

13

NO

REMARKS DEFICIENCIES/TEM PORARY ARRANAGEMENT IF ANY

All nuts and bolts of bus bar are tightened correctly as per specified torque All clamps and connectors are as per the drawings issues by Engineering. department and correctly tightened as per specified torque Any paint removed / scratched in yard equipments have been touched up

148 Bay/Feeder

No. CF/BAY/06/ R-3 DATED 01/04/2011

Doc No. D-2-01-03-01-03

14

17

Bay identification and designation plate are on position with R,Y,B phase marking Gravel filling in the yard (if designed) has been done The ladders / tools / vehicles / work bench/ temporary earthing etc. Removed from the area which is to be energized DC emergency light in operation and in auto

18

DG set is available and in operation

19

Switching sequences with procedures are documented and available in the control room Regular operation in the control room is manned round the clock with regular operation staff All PTW issued earlier are cancelled and nothing are pending Operation data log sheets, PTW and other standard formats of Powergrid are available for regular operation Confirm color coding of all equipments and phase marking Check star points of CT & CVT secondary and associated links if any Check that treated earth pits are covered and numbered Check the tightness of the connecting links of treated earth pits Core wise secondary injection test for both CTs and PTs inputs from secondary terminal box of CT/PT done to detect any mixing/ interchanging of cores/ phases Fuse fail protection checked for m1, m2, backup impedance etc Necessary clearances as applicable have been obtained Charging clearance is received from grid operation CPCC / IOCC / REB vide msg no :________ Time__________Dated__________

15 16

20 21 22

23 24 25 26 27

28 29 30

VII.

MEASUREMENT OF EARTH RESISTANCE SL.NO

LOCATION DESCRIPTION

DISTANCE BETWEEN ELECTRODE

RESISTANCE

LOCATION – 1 LOCATION - 2 LOCATION - 3 LOCATION - 4 LOCATION - 5 LOCATION - 6

Permissible limit = 1.0 ? (MAX) No. CF/BAY/06/ R-3 DATED 01/04/2011

Bay/Feeder 149

Doc No. D-2-01-03-01-03

VIII.

CONTACT TIGHTNESS CHECK BY PRIMARY CURRENT INJECTION

CURRENT INJECTION AT

IX.

REMARKS ON CONTACT HEALTHINESS

SOIL RESISTIVITY

REMARKS

CHECK THE MINIMUM CLEARANCE BETWEEN LIVE PARTS W.R.T GROUND AND BETWEEN LIVE PARTS VOLTAGE

PHASE TO GROUND

PHASE TO PHASE

132 kV 220 kV 400 kV 765 KV

1270 mm 2082 mm 3065 mm 6400 mm

1473 mm 2368 mm 5750 mm 9400 mm

REMARKS, IF ANY

phases & phase to ground are to be checked as per the

CHECKING OF INTERLOCKS

i. ii.

XII.

CURRENT MEASURED

DISTANCE BETWEEN ELECTRODE

Note : All the clearance between drgs. issued by Engg. Dept.

XI.

CURRENT INJECTED

MEASUREMENT OF SOIL RESISTIVITY DO NE EARLIER PRIOR TO COMMISSIONING

DATE

X.

CURRENT MEASURED AT

Please refer the relevant plant circuit diagram for checking the interlocks of various equipments to be energized. Yes No Remarks All isolators and ground switches Inter locking checked as per the Document no CF/ISO/08

TRIP TEST

All breakers are tested and all the trip test as per the required plant circuit diagrams are carried out as per the document No CF/CB/05 150 Bay/Feeder

Yes

No

Remarks

No. CF/BAY/06/ R-3 DATED 01/04/2011

Doc No. D-2-01-03-01-03

XIII.

STABILITY TEST FOR BUSBAR

Details of kit used : To be done in line with approved scheme i. PHASE

Bus earth switch open PRIMARY INJECTION BETWEEN CTs

CURRENT VALUE

SPILL CURRENT VALUE

REMARKS

CURRENT VALUE

SPILL CURRENT VALUE

REMARKS

R Y B R Y B R Y B

ii. PHASE

Bus earth switch closed PRIMARY INJECTION BETWEEN CTs

R Y B R Y B R Y B

XIV.

FINAL TRIP TEST The trip test must be repeated prior to energization as per approved scheme. Tripping operation to be checked for both the trip coils from local/ remote/ protection

i. SL. NO I II III IV V VI VII VIII

DC source 1 off PROTECTION TYPE

SIMULATION METHOD

CB TRIP RESPONSE MAIN TIE

REMARKS

Main - I Main – II Over voltage Carrier inter tripping LBB Bus bar Tee differential Differential

No. CF/BAY/06/ R-3 DATED 01/04/2011

Bay/Feeder 151

Doc No. D-2-01-03-01-03

IX X XI XII XIII XIV XV XVI XVII XVIII XIX

ii. SL. NO I II III IV V VI VII VIII IX X XI XII XIII XIV XV XVI XVII XVIII XIX

Restricted earth fault Back up o/c & e/f Over fluxing OTI trip WTI trip Buchholz trip (main ) Buchholz trip (OLTC) PRD Auto-reclose - R ø Auto-reclose - Y ø Auto-reclose - B ø DC source 2 off PROTECTION TYPE

SIMULATION METHOD

CB TRIP RESPONSE MAIN TIE

REMARKS

Main - I Main – II Over voltage Carrier inter tripping LBB Bus bar Tee differential Differential Restricted earth fault Back up o/c & e/f Over fluxing OTI trip WTI trip Buchholz trip (main ) Buchholz trip (OLTC) PRD Auto-reclose - R ø Auto-reclose - Y ø Auto-reclose - B ø

Operational Constraints if any

152 Bay/Feeder

No. CF/BAY/06/ R-3 DATED 01/04/2011

Doc No. D-2-01-03-01-03

XV.


i.


ii.


Yes

No

Yes

No

Yes

No

Yes

No


iv. The above Bay/Feeder is cleared for high voltage energisation

Signature:

Signature:

Signature:

Signature:

Name:

Name:

Name:

Name:

Designation:

Designation:

Designation:

Designation:


(Erection Agency)


(POWERGRID Commissioning Team) Members:

No. CF/BAY/06/ R-3 DATED 01/04/2011

Bay/Feeder 153

Doc No. D-2-01-03-01-03

PRE-COMMISSIONING FORMATS FOR ISOLATOR AND GROUNDING SWITCH GENERAL DETAILS

I.

DETAILS Sub-Station:

Region: Feeder name

LOA No. :

Make:

Type:

Sr. No.: RØ:YØ:BØ:Control Volatge:

Operating Voltage rating

Year of Manufacture: RØ:YØ:BØ:Date of Erection: RØ:YØ:BØ:-

Date of Receipt at site: R Ø:YØ:BØ:Date of energisation

Current Carrying capacity:

PRE-COMMISSIONING CHECKS

II.

STATUS SL.NO

DESCRIPTION YES

1 2 3 4 5 6 7 8 9 10 11 12 13 14

NO

REMARKS / RECORD DEFICIENCIES, IF ANY

Equipment is free from dirt/dust foreign materials etc. Equipment is free from all visible defects on physical inspection Support structures, marshalling box has been provided with two earthing pads / points All nuts and bolts are tightened correctly as per specified torque Equipment erection is complete in all respect as per instruction Manual (attach remaining activities, if any) Permanent isolator lavelling and identification is done Leveling and alignment of structure and base frame is checked Control box / marshalling kiosk is free from any physical defects Tightness of nuts bolts of terminal connectors are checked Auxiliary contacts and relays have been cleaned and free from rust / damage Corona rings are provided and properly fixed Cable termination and tightness checked and unused holes sealed External cabling is completed in all respect All the cable identification tags provided and all cores are provided with Identification ferrules at m.b.

154 Isolator

No. CF/ISO/07/ R-3 DATED 01/04/2011

Doc No. D-2-01-03-01-03

15

All moving parts are lubricated

16

Alignment of isolator already made to be checked and locking bolt provided, if any

17

Freeness of manual operation is ok Greasing has been made on the main contacts according to the manufacturers instruction Functional checking of auxiliary contacts for indications and interlocks Erection completion certificate along with list of outstanding activities reviewed All spare wires to be kept with ferrules but not terminated at the terminal blocks

18 19 20 21 22 23

Earth switch connected to earth through braided wires Interlocks checked as per approved scheme with all combinations Check that earth switch blade alignment in condition is at sufficient distant from isolator Check that operation and positioning of the limit switch & the auxiliary contacts assembly are ok Check that all three phase isolators are closing & opening at a time Check all 3 earth switches close at the same time

24 25 26 27 28

Provision of bimetallic strips ensured wherever applicable

III.

MOTOR DETAILS R-Ø

Y-Ø

B-Ø

Make Serial number Type Year of manufacturer Volt Amperes Hp/ kW O/L setting (Thermal Over load)

IV.

INSULATION RESISTANCE MEASUREMENT Make of testing kit Date of calibration Ambient temperature

Using 500 volt megger measure resistance between the winding of motor and earth BETWEEN

SL. NO

PHASE R Ø

1

YØ

B Ø

Winding to Earth

PERMISSIVE VALUE >

1000 M.OHM

No. CF/ISO/07/ R-3 DATED 01/04/2011

Isolator 155

Doc No. D-2-01-03-01-03

V.

OPERATIONAL CHECKS i.

Operate the isolator and record the motor current MOTOR CURRENT R-Ø ISOLATOR OPERATION

FACTORY

Y-Ø SITE

B-Ø SITE

FACTORY

FACTORY

SITE

CLOSE OPEN

ii.

Operation of isolator from local / remote Ok/Not Ok CONTROL PANEL

ISOLATOR OPERATION

LOCAL

REMOTE

CLOSE OPEN

iii.

Measurement of operating time PHASE

OPERATION

UNIT R-Ø

Y-Ø

B-Ø

OPENING TIME CLOSING TIME

iv.

Auxiliary contacts checking OPERATION TIME ISOLATOR OPERATION

AUXILLARY RELAY TYPE

R-Ø NO

Y–Ø NC

NO

B-Ø NC

NO

NC

CLOSE

OPEN

Reference drawing no: 156 Isolator

No. CF/ISO/07/ R-3 DATED 01/04/2011

Doc No. D-2-01-03-01-03

v.

OPERATION ON UNDER VOLTAGE CONDITION CONDITION

PHASE

COIL

UNIT R-Ø

PICK UP VOLTAGE

DROP VOLTAGE

VI.

CLOSING

VOLT DC

OPENING

VOLT DC

INTERLOCK

VOLT DC

CLOSING

VOLT DC

OPENING

VOLT DC

INTERLOCK

VOLT DC

Y-Ø

B-Ø

INSULATION RESISTANCE MEASUREMENT (By 5kV Megger) Make of t esting kit Date of calibration Ambient temperature Isolator open condition BETWEEN

PHASE R Ø

YØ

B Ø

MALE SIDE TO GROUND FEMALE SIDE TO GROUND MALE SIDE TO FEMALE SIDE PERMISSIVE VALUE

VII.

> 1000 M.OHM


(To be measured after 50 operation) Make of testing kit __________ __________________ Date of calibration

i.

__ ___________________________

Isolator Close condition CONTACT RESISTANCE

Connector(Male Side) Connector(Female Side) Main Contact(Male & Female)

UNITS

R-Ø

Y-Ø

B-Ø

µ? µ? µ?

The value of Contact Resistance should not be more than 10 Micro – ohms per / Connector ii.

Isolator Open condition and grounding switch close condition

CONTACT RESISTANCE

Main Contact(Male & Female) Ground Switch

UNITS

R-Ø

Y-Ø

B-Ø

µ?

The value of Contact Resistance should not be more than 150 Micro – ohms per / Connector

No. CF/ISO/07/ R-3 DATED 01/04/2011

Isolator 157

Doc No. D-2-01-03-01-03

VIII.

i.

Resistance of operating coil

_______________________________

ii.

Resistance of interlocking coil________________________________


IX.

i.


ii.


iii.

Yes

No

Yes

No

Yes

No


Signature:

Signature:

Signature:

Signature:

Name:

Name:

Name:

Name:

Designation:

Designation:

Designation:

Designation:


(Erection Agency)



158 Isolator

No. CF/ISO/07/ R-3 DATED 01/04/2011

Doc No. D-2-01-03-01-03

PRE-COMMISSIONING FORMATS FOR SURGE ARRESTER GENERAL DETAILS

I.

DETAILS Region:

Sub-Station:

Feeder name

LOA No. :

Make:

Type:

Sr. No.: RØ:YØ:BØ:Rating:

Voltage rating

Feeder name:

Year of Manufacture: R Ø:YØ:BØ:Date of Erection: R Ø:YØ:BØ:-

Date of Receipt at site: RØ:YØ:BØ:Date of energisation


II. SL. NO.

1 2 3 4 5 6 7 8 9 10 11 12

13 14 15 16 17

DESCRIPTION

STATUS YES

NO

REMARK RECORD DEFICIENCIES, IF ANY

Equipment is free from dirt / dust foreign materials etc. Equipment is free from all visible defects on physical inspection Support structures have been provided with double earth All nuts and bolts are tightened correctly as per specified torque Equipment erection is complete in all respect (attach remaining activities, if any) Permanent LA leveling andidentification is done Leveling and alignment of structure and base frame is checked All insulators & surge counter are free from any physical defects Tightness of nuts bolts of terminal connectors are checked Erection completion certificate along with list of outstanding activities reviewed Check one end of surge counter is connected to the bottom of LA stack and one end of surge counter has been earthed The direction of the exhaust vent ports away from the protected equipment and other arrester poles Clearance from the arrester to earthed objects and from the arrester pole to another arrester pole maintained as per outline drawing and all erection has been done as per drawing issued by engg. Dept. Operation of LA counter checkedby applying appropriate voltage Check the serial no. and sequence of LA parts for erection in multi stack LA Check the alignment of corona ring Check on charging, the surge counter pointer is in green zone

No. CF/SA/08/ R-3 DATED 01/04/2011

Surge Arrester 159

Doc No. D-2-01-03-01-03

III.

INSULATION RESISTANCE MEASUREMENT : ( USING 5kV MEGGER) PHASE SL. NO

BETWEEN

UNIT R Ø

1 2 3 4 5 6

YØ

BØ

M? M? M? M? M? M?

1st stack & earth 2nd stack & earth 3rd stack & earth 4th stack & earth 5th stack & earth 6th stack & earth

MIN VALUE > 1000 M OHMS

IV.

SURGE COUNTER READING SL.NO

READING

1 2 3

V.

RØ

YØ

BØ

Counter sr. No. Counter make Counter reading

CAPACITANCE & TAN DELTA MEASUREMENT TAN DELTA

CAPACITANCE

STACK

REMARKS SITE

FACTORY

%DEVIATION

SITE

FACTORY

%DEVIATION

Top Middle 1 Middle 2 Bottom Permissible Limits Tan ä 0.007 (max.) and Rate of rise in Tan Delta 0.001 per year (max) Deviation of Capacitance value from factory value should be within ± 5% of the rated value 1 Since temperature correction factor for Tan-Delta depe nds on make, type andsoalaging conditions, the correction factors for different types / makes are different. Hence, no standard temperature correction factors can be applied. 2 In case of violation of Tan-Delta the test results with temperature are to be referred to CC/OS

VI.

CHECKING OF HEALTHINESS OF SURGE MONITOR Refer manufacturer’s catalogue for detail checking of surge monitor

VII.

Yes

No

THIRD HARMONIC RESISTIVE CURRENT MEASUREMENT AMBIENT TEMPERATURE __________ ___________________ SYSTEM VOLTAGE____________________________ PH

TOTAL CURRENT

3RD HARMONIC RESISTIVE CURRENT (I3 R) in A

REMARKS

R Y B

160 Surge Arrester

No. CF/SA/08/ R-3 DATED 01/04/2011

Doc No. D-2-01-03-01-03

The value of third harmonic current after compensation shall be less than 30 µa. In case of discrepancy, test results to be forwarded to CC/OS. I.


i.


ii.


Yes

No

Yes

No

Yes

No


Signature:

Signature:

Signature:

Signature:

Name:

Name:

Name:

Name:

Designation:

Designation:

Designation:

Designation:


(Erection Agency)



No. CF/SA/08/ R-3 DATED 01/04/2011

Surge Arrester 161

Doc No. D-2-01-03-01-03

PRE-COMMISSIONING FORMATS FOR WAVE TRAP GENERAL DETAILS

I.

DETAILS Region:

Sub-Station:

Feeder name

LOA No. :

Make:

Type:

Sr. No.: RØ:YØ:BØ:mH Rating:

Voltage rating

Current Rating:

Band Width: Date of Receipt at site: RØ:YØ:BØ:Date of energisation

Year of Manufacture: RØ:YØ:BØ:Date of Erection: R Ø:YØ:BØ:-

PRE-COMMISSIONING CHECKS

II.

STATUS SL NO

DESCRIPTION YES

1 2

Equipment is free from dirt / dust foreign materials etc. Equipment is free from all visible defects on physical inspection

3 4

Support structures has been provided with double earth All nuts and bolts are tightened correctly as per specified torque

5

Permanent lavelling and identification is done

6

Leveling and alignment of structure and base frame is checked All insulators & line matching unit are free from any physical defects Tightness of nuts / bolts of terminal connectors are checked Erection completion certificate along with list of outstanding activities reviewed Check that the tuning unit and arrestor are properly tightened and free from any damage

7 8 9 10

162 Wave Trap

NO

RECORD DEFICIENCIES, IF ANY

No. CF/WT/09/ R-3 DATED 01/04/2011

Doc No. D-2-01-03-01-03

III.

INSULATION RESISTANCE MEASUREMENT Make of testing kit

__________ _____________________

Date of calibration

__ ___________________________

Ambient temperature ______ _________________________ SL. NO

BETWEEN

PHASE

MEGGER RØ

1

UPPER TEMINAL AND EARTH

2

LA OF THE WAVE TRAP

YØ

PERMISSIVE VALUE

BØ

5000 V

> 1000 M.OHM

500 V

> 1 M.OHM


IV.


__________ __________________ __ ___________________________

CONTACT RESISTANCE

UNITS

R-Ø

Y-Ø

B-Ø

µ? µ?

Across Terminal P1 Across Terminal P2

The value of Contact Resistance should not be more than 10 Micro – ohms per Joint / Connector V.


i.


ii.


iii.

Yes

No

Yes

No

Yes

No


Signature:

Signature:

Signature:

Signature:

Name:

Name:

Name:

Name:

Designation:

Designation:

Designation:

Designation:


(Erection Agency)



No. CF/WT/09/ R-3 DATED 01/04/2011

Wave Trap 163

Doc No. D-2-01-03-01-03

PRE-COMMISSIONING CHECK LIST FOR CONTROL & PROTECTION INCLUDING PLCC LINE PROTECTION General Details Region:

Sub-Station:

Feeder Name: Date of testing:

LOA No. : Date of Energisation:

Main-I/II Protection Panel 1. Main-I /II Distance relay: (separate for Main-I & II Relays) i a ii

b c

iii iv v vi vii viii

ix

x

Check for proper programming of Input / Output contacts of the OK/ NOT OK relay as per approved schematics Check for proper programming of LED’s(if applicable) of the OK/ NOT OK relay and check that stickers are provided as per the configuration. Check Configuration / Programmable Scheme Logic of relay OK/ NOT OK according to scheme (applicable for numerical relays) Get the print out of Configuration / PSL OK/ NOT OK Get a print of relay settings OK/ NOT OK Compare with the recommended setting OK/ NOT OK Check for Reach Setting : Zone- I, II, III,IV OK/ NOT OK Check time of operation : Zone- I, II, III,IV OK/ NOT OK Test results of (iii) & (iv) enclosed YES/ NO Check polarity of send & receive for PLCC command (If Digital OK/ NOT OK Channel/ Under FET operation) Check Permissive tripping by Carrier command receive and OK/ NOT OK measure & record relay operation time for carrier aided trip. Also check Carrier Send command on relay tripping Verify respective counter advancement in each channel Send Recv CH….. Code……… CH….. Code……… OK/ NOT OK Main-I CH….. Code……… CH….. Code……… OK/ NOT OK CH….. Code……… CH….. Code……… OK/ NOT OK Main-II CH….. Code……… CH….. Code……… OK/ NOT OK Check Blocking scheme (if applicable) along with carrier OK/ NOT OK command for both send & receive. Verify respective counter advancement in each channel Send Recv CH….. Code……… CH….. Code……… OK/ NOT OK Main-I CH….. Code……… CH….. Code……… OK/ NOT OK

164 Control & Protection

No. CF/C&P/10/ R-3 DATED 01/04/2011

Doc No. D-2-01-03-01-03

CH….. Code……… CH….. Code……… CH….. Code……… CH….. Code……… Check SOTF Logic. Check Control switch( TCS) & wirings on Control panel to Relay Input for SOTF( if provided) Check Weak-end in-feed logic Check Selective Phase tripping( R Ph fault to R-Ph Trip etc) for each phase separately Check Power swing blocking feature (if available) Check trip Block in case of CVT Fuse Failure Check Auto Reclose Initiation Contacts for Transient Single Phase Earth fault(Zone-1&Zone-2+CR) Non initiation for 1 phase fault in Zone II Transient Ph-Ph Fault Transient 3 Phase Faults Permanent Faults(Prepare 3Ph Trip) Check for dead time and reclaim time setting Check single phase auto reclosure for all three phases one by one. Check for tripping command directly to CB & correct operation of tripping relays and auxiliary relays Check Communication to PC keeping adjacent relay IN&OUT of service (If available) Check PLCC carrier Switch Operation( In/Out). Check Time synchronizing by altering Time Zone. Restore on confirmation Check Self-diagnostic feature of the relay (if provided) Check metering function of the relay (if provided) Verify automatic downloading feature as per Tech spec. Verify open delta voltage in DR channel Verify availability of configura tion tool at site. Verify Main & Tie CT circuits by primary injection Check directionality of the relay after synchronization of the line Check for DEF protection and its contacts (if applicable) Check all the contacts of relay for proper operation & rating Main-II

xi xii xiii xiv xv a b c d e f g

xvi

xvii xviii xix xx xxi xxii xxiii xxiv xxv xxvi xxvii xxviii xxix

OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK

2. Overvoltage Stage-I/II i ii

Check Operate Value/Reset Value/Operate timing for all phases. Check whether it trips Main/Tie CB & sends Direct trip to remote end

OK/ NOT OK YES/ NO

3. Stub protection (4 CT scheme) i ii iii

Check scheme logic Check operation at set value Check Direct Trip send & receive circuit with carrier command. Verify counter advancement in each channel

No. CF/C&P/10/ R-3 DATED 01/04/2011

OK/ NOT OK OK/ NOT OK OK/ NOT OK

Control & Protection 165

Doc No. D-2-01-03-01-03

4.

TEE Differential-I/II (5 CT scheme)

i ii iii iv.

Check Operate Value/Reset Value/Oper ate Timing for all phases Check tripping of Main/Tie CB & send Direct trip to remote end Check stability for out zone fault If Biased differential, check Biasing percentage for all phases

OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK

5. Fault Locator Feed FL & Distance relay with same Voltage & Current from test Kit. Simulate Zone-I/II, Single Ph/Ph-Ph/3Ph Fault to Main-I/II Distance relay. i ii iii iv.

Check initiation by Distance relay Compare Fault location by calculating the Set Vale on test Kit Repeat the above up to 99% in steps Check healthiness of mutual compensation circuit


6. Disturbance Recorder i ii iii iv v vi vii

Check analog & digital channels are connected as per approved OK/ NOT OK nomenclature Check threshold value of analog triggering (including open delta OK/ NOT OK voltage). Check triggering on digital inputs OK/ NOT OK Check automatic downloading feature OK/ NOT OK Check time synchronizing feature OK/ NOT OK Verify open delta voltage in DR channel OK/ NOT OK Check diagnostic feature(if provided) OK/ NOT OK

7. Final Documentation Review S.No.

1. 2. 3.

Description

Status (Yes/ No)

Remarks(Record deficiencies, if any)

Final document of Pre-commissioning checks reviewed and approved Documents regarding spares, equipment, factory reports, O&M manuals etc. available at site for O&M purpose After modification, if any, “As built drawing are available at site

Signature: Name: Desgn.: Organization: (Supplier Representative) (Wherever Applicable)


Signature: Name: Desgn.:



(Erection Agency)



No. CF/C&P/10/ R-3 DATED 01/04/2011

Doc No. D-2-01-03-01-03

Circuit-Breaker Panel General Details Region:

Sub-Station:



Auto-reclose Scheme: (Checks applicable for distance protection scheme with auto re-closure function as well)

1.

a b c d e

i

ii iii iv v vi vii viii ix

a b c d e f

x

xi

xii xiii

xiv

Check auto reclose initiation/Block contacts for Transient Single Phase Earth fault Non initiation for 1 phase fault in Zone II Transient Ph-Ph Fault Transient 3 Phase Faults Permanent Faults Simulate Zone-I ,Single Ph Transient E/F to Main-I/II Distance relay Check AR for all 3 Phases,one by One Loop CS & CR, Simulate Zone-II ,Single Ph Transient E/F to Main-I/II Distance relay Check AR for all 3 Phases, one by One Check settings & operation of Synchronizing/DLC relays Measure Dead Time setting ………………ms Measure Reclaim Timer setting Check AR does not take place within reclaim time Check AR does not take place in case of fault on Line Charging. Check AR does not take place in case of Failure of PLCC Carriers Further, check AR Interlocking in case of Pole discrepancy Direct trip received Over-voltage stage-I/II trips Reactor protection trips CB Troubles Zone-2 & 3 time delayed faults In a one & half / Two CB scheme, Check AR does not take place for any one of the CBs under S/D. Check Memory Circuit Contact status( CB Closed/Opened conditions). Check Memory Circuit Timer setting. Check Logics of AR switch Operation ( NA/1Ph/2Ph/3Ph). Check priority circuitry. Priority circuit of Tie CB should be bypassed is any of the main CB is kept in Non Auto mode due to shutdown or outages A/R should not take place in NON AUTO mode

No. CF/C&P/10/ R-3 DATED 01/04/2011

OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK

OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK

OK/ NOT OK OK/ NOT OK

OK/ NOT OK


Doc No. D-2-01-03-01-03

2.

Local Breaker Back Up Protection: i

Check Operate Value/Reset Value/Oper ate Timing for all phases Check adjacent CB’s as well as concerned Bus-Bar Trip relays operate during operation of LBB relay Check Direct trip Transfer takes place only for feeder under testing during LBB operation

ii iii


3. Under-voltage Relay i

Check Operate Value/Reset Value/Operate Timing for all phases Check E/S interlock operation under relay energized condition & vice versa

ii

4.


Direct Trip Transfer a. Check Direct trip transfer in case of: i ii iii iv v vi vii viii ix x

Over-voltage relay operations Reactor trip operations. Manual trip to One CB(Main/Tie) when another CB(Tie/Main) in same dia is under open condition LBB relay Trip: for both the main & tie CB’s Busbar Trip to One CB(Main/Tie) when another CB(Tie/Main) in same dia is under open condition TEE Diff/ STUB Protection trip Direct trip Transfer thr’ 1 st Chanel Direct trip Transfer thr’ 2nd Chanel Check DT is not resulted by 1 st Chanel permissive trip Check DT is not resulted by 2nd Chanel permissive trip

OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK

b. Summary of Code Transfer for PLCC Ch-1 Code-I……… Ch-1 Code-2……… Ch-2 Code-I ……… Ch-2 Code-2 ……… i ii iii iv v vi vii viii

Check individual Code Transfer to be as per scheme Ch-1 Code-I Ch-1 Code-2 Ch-1 Code-3 Ch-2 Code-I Ch-2 Code-2 Ch-2 Code-3 Check if signal through One code is not transferred to another at Remote end


OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK

No. CF/C&P/10/ R-3 DATED 01/04/2011

Doc No. D-2-01-03-01-03

5.

CB Troubles

i ii iii

6.

Check whether All relays are given elaborative nomenclatures. If OK/ NOT OK not, Paste descriptions (CB LOW Air/Oil pressure, Pole discrepancy etc.) Check Operations of individual Relays by actuating initiating OK/ NOT OK Contacts from field Check facia/Event Logger Input Contacts for the same OK/ NOT OK

Final Documentation Review

S.No. 1. 2. 3.

Status (Yes/ No)

Description







(Erection Agency)



No. CF/C&P/10/ R-3 DATED 01/04/2011


Doc No. D-2-01-03-01-03

Line Reactor Protection

General Details Region:

Sub-Station:



1.

Differential Protection

i ii iii iv v vi vii viii ix

2.

CT secondary Circuitry Checked & Diff current is Nil by Primary Injection for all Phases Check connection of stabilizing resistance & metrosil (wherever applicable) If fed from Turret CT’s from both sides of Phase Windings. Check Operate Value/Reset Value/Operate Timing for all phases Measure differential pick up current Carry out stability test by simulating external and internal faults and measure spill currents in Differential circuit Check Biasing percentage, Operate Value/Reset Value/Operate including High set feature if applicable Timing for all phases(if biased / percentage differential) Check Blocking of tripping on Harmonic Restraints Feature ( 2nd & 5th harmonics) Check DR feature (if available)

OK/ Value…. OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK

Restricted Earth-Fault Protection:

i ii iii iv v vi vii

Check Operate Value/Reset Value/Oper ate Timing for all phases CT secondary Circuitry Checked & Diff current is Nil by Primary Injection for all Phases Check connection of stabilizing resistance & metrosil (wherever applicable) Check CT Circuits so that summation of same phases(R-R, Y-Y, B-B) is taking place (Sometimes R-B & B-R summations are observed due to wrong Wirings). If fed from Turret CT’s from both sides of Phase Windings. Check Operate Value/Reset Value/Operate Timing for all phases Measure differential pick up current Carry out stability test by simulating external and internal faults by primary injection and measure spill currents in REF relay


OK/ NOT OK OK/ Value…. OK/ NOT OK OK/ NOT OK


No. CF/C&P/10/ R-3 DATED 01/04/2011

Doc No. D-2-01-03-01-03

3.

Back-Up Impedance Relay i ii iii iv v vi vii viii ix x xi xii

Type :…………

Get a print of relay settings(wherever applicable) Compare with recommended setting Check for Reach Setting Check time of operation Test results of (iii) & (iv) enclosed Check Selective Phase tripping( R Ph fault to R-Ph Trip etc) Check trip Block in case of CVT Fuse Failure. Check Communication to PC(If available) Check Time synchronizing by altering Time Zone. Restore on confirmation Check Self-diagnostic feature of the relay (if provided) Check metering function of the relay (if provided) Verification of Directionality

OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK YES/NO OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK

Electromechanical Relays : Check operation of:

4. i ii iii iv v 5.

Buchholz Alarm & trip WTI Alarm & trip OTI Alarm & trip PRD Trip MOG(LOL/Low Oil Level) Alarm

OK/ NOT OK Alarm………Trip……….. Alarm………Trip……….. OK/ NOT OK OK/ NOT OK

Direct Trip Transfer i ii

6.

In all cases of above trippings, Direct trip to remote end is sent along with tripping of Main/Tie CB’s Direct trip: From line Reactor LBB in case of switchable reactor


Voltage selection for Protection & Metering

i

ii

Ensure Voltage inputs at specific terminals from a Line CVT b Bus-I CVT( say connected to CB-1) c Bus-II CVT( say connected to CB-2) Check NO/NC Contacts from CB-1 & CB-2 for voltage selection Open Line Isolator: Close CB-1 : Bus-I CVT supply will be selected. Check CVT Supply at selected CVT Terminals for Metering & Protection. Trip CB-1 Close CB-2 : Bus-II CVT supply will be selected. Check CVT Supply at selected CVT Terminals for Metering & Protection. Trip CB-2. Close Line Isolator: Line CVT supply will be selected. Close CB-1 & 2, No change in status of Selection relays.

No. CF/C&P/10/ R-3 DATED 01/04/2011

OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK

OK/ NOT OK

OK/ NOT OK


Doc No. D-2-01-03-01-03

7.

Check RWTI on Control panel i

8.

RWTI checked on control panel


S.No.

1. 2. 3.

OK/ NOT OK

Description

Status (Yes/ No)








(Erection Agency)



No. CF/C&P/10/ R-3 DATED 01/04/2011

Doc No. D-2-01-03-01-03

Bus Reactor Protection


Sub-Station:



1.

Differential Protection i ii iii iv v vi vii

2.

CT secondary Circuitry Checked & Diff current is Nil by Primary Injection for all Phases Check connection of stabilizing resistance & metrosil (wherever applicable) Check CT Circuits so that summation of same phases(R-R, Y-Y, B-B) is taking place (Sometimes R-B & B-R summations are observed due to wrong Wirings) If fed from Turret CT’s from both sides of Phase Windings. Check Operate Value/Reset Value/Operate Timing for all phases Measure differential pick up current Carry out stability test by simulating external and internal faults and measure spill currents in Differential circuit Check Biasing percentage, Operate Value/Reset Value/Operate including High set feature if applicable

OK/ Value…. OK/ NOT OK


Restricted Earth-Fault Protection: i ii iii iv v vi vii


No. CF/C&P/10/ R-3 DATED 01/04/2011




Doc No. D-2-01-03-01-03

3.

Back-Up Impedance Relay i ii iii iv v vi vii viii ix x xi

4.

Type :…………

Get a print of relay settings(wherever applicable) Compare with recommended setting Check for Reach Setting Check time of operation Test results of (iii) & (iv) enclosed Check trip Block in case of CVT Fuse Failure. Check Communication to PC(If available) Check Time synchronizing by altering Time Zone. Restore on confirmation Check Self-diagnostic feature of the relay (if provided) Check metering function of the relay (if provided) Verification of Directionality

OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK YES/NO OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK

Electromechanical Relays i ii iii iv v

5.

Buchholz Alarm & trip WTI Alarm & trip OTI Alarm & trip PRD Trip MOG(LOL/Low Oil Level) Alarm

OK/ NOT OK Alarm………Trip……….. Alarm………Trip……….. OK/ NOT OK OK/ NOT OK

Direct Trip Transfer

i ii

6.

In all cases of above trippings, Direct trip to remote end is sent along with tripping of Main/Tie CB’s Direct trip: From line Reactor LBB in case of switchable reactor


Voltage selection for Protection & Metering

i

ii

Ensure Voltage inputs at specific terminals from a Line CVT b Bus-I CVT( say connected to CB-1) c Bus-II CVT( say connected to CB-2) Check NO/NC Contacts from CB-1 & CB-2 for voltage selection Open Line Isolator: Close CB-1 : Bus-I CVT supply will be selected. Check CVT Supply at selected CVT Terminals for Metering & Protection. Trip CB-1 Close CB-2 : Bus-II CVT supply will be selected. Check CVT Supply at selected CVT Terminals for Metering & Protection. Trip CB-2. Close Line Isolator: Line CVT supply will be selected. Close CB-1 & 2, No change in status of Selection relays.



OK/ NOT OK

OK/ NOT OK

No. CF/C&P/10/ R-3 DATED 01/04/2011

Doc No. D-2-01-03-01-03

7. Check RWTI on Control panel i

8.



S.No.

1. 2. 3.

OK/ NOT OK

Description

Status (Yes/ No)



Signature: Name: Desgn.: Organization: (Supplier Representative) (Wherever




(Erection Agency)



No. CF/C&P/10/ R-3 DATED 01/04/2011


Doc No. D-2-01-03-01-03

Auto-Transformer Protection


Sub-Station:



1.

Differential Protection


2.

CT secondary Circuitry Checked & Diff current is Nil by Primary Injection for all Phases Check connection of stabilizing resistance & metrosil (wherever applicable) Check CT Circuits so that summation of same phases(R-R, Y-Y, B-B) is taking place (Sometimes R-B & B-R summations are observed due to wrong Wirings) If fed from Turret CT’s from both sides of Phase Windings. Check Operate Value/Reset Value/Operate Timing for all phases Measure differential pick up current Carry out stability test by simulating external and internal faults and measure spill currents in Differential circuit Check Biasing percentage, Operate Value/Reset Value/Operate including High set feature if applicable

OK/ Value…. OK/ NOT OK OK/ NOT OK


Restricted Earth-Fault Protection






No. CF/C&P/10/ R-3 DATED 01/04/2011

Doc No. D-2-01-03-01-03

Electromechanical Relays: Check Operations of :

3.


4.

Buchholz Alarm & trip WTI Alarm & trip OTI Alarm & trip PRD Trip MOG(LOL/Low Oil Level) Alarm Oil surge relay OLTC Protections

OK/ NOT OK Alarm………Trip……….. Alarm………Trip……….. OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK

Direct Trip Transfer

i 5.

In all cases of above trippings, Direct trip to remote end is sent along with tripping of Main/Tie CB’s

OK/ NOT OK

Voltage selection for Protection & Metering Ensure Voltage inputs at specific terminals from a Line CVT b Bus-I CVT( say connected to CB-1) c Bus-II CVT( say connected to CB-2) Check NO/NC Contacts from CB-1 & CB-2 for voltage selection Open Line Isolator: Close CB-1 : Bus-I CVT supply will be selected. Check CVT Supply at selected CVT Terminals for Metering & Protection. Trip CB-1 Close CB-2 : Bus-II CVT supply will be selected. Check CVT Supply at selected CVT Terminals for Metering & Protection. Trip CB-2. Close Line Isolator: Line CVT supply will be selected. Close CB-1 & 2, No change in status of Selection relays.

i

ii

6.


OK/ NOT OK

OK/ NOT OK

Check RWTI on Control panel i

7.


OK/ NOT OK

Over Flux Relay i ii

8.

Checking of Pick up drop off value(Alarm ) Checking of Pick up drop off value(Trip )


Transformer Overload Relay i ii iii iv

Check Operation of alarm Function Operate Value of Current in secondary Terms Check time of operations Check if trip is provided on O/L

No. CF/C&P/10/ R-3 DATED 01/04/2011

OK/ NOT OK ……………. OK/ NOT OK Provided/ Not provided Control & Protection 177

Doc No. D-2-01-03-01-03

9.

Directional Back-Up O/C & E/F Relay

i ii iii iv v 10.

Check Voltage-Current Circuit (Ir –V……., Iy - V……., Ib - V………) Check Voltage/Current summa tion for E/F relay Check Directional element Operation Check time of operation with different operating current Attach Graph for IDMT operation for future ref. Final Documentation Review

S.No.

1. 2. 3.


Description

Status (Yes/ No)








(Erection Agency)

(POWERGRID Site


No. CF/C&P/10/ R-3 DATED 01/04/2011

Doc No. D-2-01-03-01-03

Control Panel


Sub-Station:



1.

Check metering circuit along with transducers first by secondary injection and there by Primary injection with Standard Voltage & Currents(as per scheme) i ii iii iv v

2.

With Voltmeter Selector switch at various positions OK/ NOT OK R-Y Y-B B-R RN YN BN With Ammeter selector switch at various positions OK/ NOT OK R Y B MW /MVAR Meters OK/ NOT OK Check metering circuits with Primary injection for each phase OK/ NOT OK separately Check for frequency Meters OK/ NOT OK

Check Isolator Interlocks i ii iii

3.

Isolator Operation when Adjacent CB Open Isolator Operation when Adjacent CB Close Check for all Bay/Line/Transformer/reactor isolators with reference to interlock scheme

OK/ NOT OK Locked/ Unlocked OK/ NOT OK

Check for Bus isolator Interlock i ii iii

4.

Check Status of E/S interlock of Bus-I/II Isolator Operation when Bus is earthed Isolator Operation when Bus is Not earthed (Checking can be done with engaging/Disengaging Contact Multiplication relay.)

OK/ NOT OK OK/ NOT OK Locked/ Unlocked

Check for E/S Interlock(Line) i ii iii

Check E/S Mech. interlock in case Line isolator is closed U/V relay Operate/Reset Voltage E/S Operation when U/V relay de-energized

No. CF/C&P/10/ R-3 DATED 01/04/2011

OK/ NOT OK …………………… OK/ NOT OK Control & Protection 179

Doc No. D-2-01-03-01-03

5.

Check for E/S Interlock(Bay) i ii iii

6.

Check E/S Mech. interlock in case isolator is closed Check E/S interlock in case isolator in same bay is closed Check E/S Aux. Contact for Local CB Close I/P

OK/ NOT OK ……………… OK/ NOT OK

Synchronization Check i ii iii iv v vi vii

viii

7.

Check DC supply at Specific Points on Synchro-Check Plug/Socket Check CVT supply at incoming running & earth Points on SyncroCheck Plug/Socket DC(+ve) to be extended to Closing Coil of CB by Synchro-Trolley No close Operation of CB W/O connecting & putting on SynchroTrolley Trip Operation is unbound Check Incoming/running voltage selection and same phase must be selected for a particular sub-station Synchronizing socket pin configuration must be same for trolly and control panel for all bays Voltage selection: Verify operating as well as resetting logic ( both logic should be mutually inverted)


Checking of Isolator Indications Isolator No…………..

i ii iii iv v vi vii viii

8.

Checking of Isolator Close Indication Checking of Isolator Open Indication Check Semaphore for E/S Close for Isolator Check Semaphore for E/S Open for Isolator Check Operation if adjacent CB closed Check Operation if adjacent CB Opened Check all NO/NC status as per scheme Check all interlock status as per scheme


Checking of CB Indications CB No………….. i ii iii iv v vi

vii viii ix x xi xii

Checking of CB Close Indication Checking of CB Open Indication Check DC healthy indication Check Local Closing I/L as per scheme Check Aux. Contact for CVT selection Check Aux. Contact for Direct trip (In series with TCS of adjacent CB) Check Aux. Contact for Sync circuit Check all Annunciations Points for CB Troubles Pole Discrepancy Timing set & Checked Pole Discrepancy Operation Checked All Pressure switch settings/contacts checked Check Anti-Hunting Operation


OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK

No. CF/C&P/10/ R-3 DATED 01/04/2011

Doc No. D-2-01-03-01-03

9.

Checking of Isolator Control Switch Isolator No………….. i

10.

Wiring & Status of Contacts as per Scheme

OK/ NOT OK

Checking of CB Control Switch CB No…………..

i ii 11.

Wiring & Status of Contacts as per Scheme Annunciation & Facia All Wo rking properly


Control Panel i ii

iii iv 12.

Check for control fuse failure Check that the control fuse failure alarm is reported to station ser by removing one of the +ve/-ve fuse in control ckt. Check that control DC is free from earthing Check there is no mixing of source I & II

ii 13.

Checking for proper functioning of Annunciation Facia with individual elements of scheme Indication for AC supply failure

3.



S.No.

2.


Facia Checking i

1.


Description

Status (Yes/ No)







(Erection Agency)



No. CF/C&P/10/ R-3 DATED 01/04/2011


Doc No. D-2-01-03-01-03

Busbar Protection General Details Region:

Sub-Station:



Relay Name

i

ii iii

iv

v

vi

vii viii ix x xi xii xiii

xiv

Zone-I………

Zone-II…………

Check Zone…………..

Check Operate Value/Reset Value/Oper ate Timing for all phases Zone-I Zone-II Check Zone Block Auto-reclose for all CB’s Connected Zone-I Zone-II If directional Element provided ,Relay tested & Direction found O.K Test results enclosed & accepted Zone-I Tripping extended to : Trip relay Location ………… for CB No………. LBB Initiated PLCC/D.T. Trip relay Location ………… for CB No………. LBB Initiated PLCC/D.T. Zone-II Tripping extended to : Trip relay Location ………… for CB No………. LBB Initiated PLCC/D.T. Trip relay Location ………… for CB No………. LBB Initiated PLCC/D.T. LBB/BFR trip checked & extended to Zone-I From CB No……………. From CB No……………. From CB No……………. LBB/BFR trip checked & extended to Zone-II From CB No……………. From CB No……………. From CB No……………. Transfer Bus Trip Checked Close Interlock in case of BB Trip Checked for all applicable CB’s RESET Working properly DC selection working properly for DC-I & II Carry out stability test by simulating external and internal faults by primary injection and measure spill currents in Bus bar diff. relay Verify stabilizing resistor & Metrosil connection(wherever applicable) Check for CT switching relay operation, in case of DMT scheme by closing respective isolators. Also inject current at the relay panel entry point and measure current at Bus Bar protection relay terminals after operating respective CT switching relay



Yes/ No Yes/ No Yes/ No Yes/ No Yes/ No Yes/ No Yes/ No Yes/ No OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK Yes/ No Yes/ No OK/ NOT OK OK/ NOT OK OK/ NOT OK

No. CF/C&P/10/ R-3 DATED 01/04/2011

Doc No. D-2-01-03-01-03

Others Region:

Sub-Station:



Relay Name

1.

Zone-I………

Zone-II…………

Check Zone…………..

Disturbance recorder i ii iii iv v vi vii viii ix x xi

xii xiii xiv xv xvi

2.

Check communication to PC/Terminals/Printers Check All Analog Inputs (R-Y-B-residual Voltages & R-Y-BNeutral currents) Check Conversion( Primary to secondary ratio) settings are programmed as per scheme Check contacts status of all digital inputs Normally six I/P’s are from Tw o CB’s. check Selective phase operation for RYB Poles for both the CB’s. Ensure proper show of Phase/Pole Check Analog threshold setting Check whether all digital Inputs are programmed for initiation of recording Disturbance as well as right status( NO/NC). Also check the sequence of digital channels as per Technical specifications Run self-diagnostic program & get a print for future reference. Otherwise, note down various Voltages at Monitoring points Simulate a disturbance by shorting contacts of a Digital I/P. Check recording in progress. Print the same Repeat the above for all digital I/P Contacts For analog threshold values (if provided), connect to Standard test kit to DR & test Threshold Value initiation of recording by Varying Voltages & Frequencies( Voltage Th reshold, Frequency thresholds & DF/DT thresholds) Check Time synchronizing by altering Time Zone in TSE. Restore on confirmation. Also check time stamping in the relays by externally triggering DR and record the error w.r.t. GPS time Check all analogue & digital inputs are configured as per power grid standard list Compare/Check analog value displayed on PC with the injected input analog value Take a print out of DR settings & keep for future reference Check for availability of proper software




OK/ NOT OK


Sequential Event Recorder i ii iii

Check communication to PC/Terminals/Printers Check contacts status of all digital inputs Check whether all digital Inputs are programmed with right status(

No. CF/C&P/10/ R-3 DATED 01/04/2011



Doc No. D-2-01-03-01-03

iv v vi vii viii

3.

NO/NC) Selective checking of each & every contacts is to be done in sequences. Print-Out/Display is to be compared Normally six I/P’s are from Tw o CB’s. check Selective Phase operation for RYB Poles for both the CB’s. Ensure proper show of Phase/Pole. Check Time synchronizing by altering Time Zone. Restore on confirmation Take a print out of plant status (if available) and compare with the actual status Check for availability of proper software & site programmability of event text



OLTC/RTCC for Transformer


4.

OLTC Operation checked from Local Panel Remote Panel Super/Control Panel Tap Position Display Correct Tap position display at local panel & at remote display with respective OLTC indicator. All Indicating lamps checked Tap Position Discrepancy Trip Master/Follower scheme Checked for Master :Xformer-1 Master :Xformer-2 Master :Xformer-3 Check auto supply changeover feature for OTLC/Transformer (If available)

OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK

General

i

ii iii iv v

vi vii

Many a time, different Auxiliary voltages are used for drive power OK/ NOT OK of DR & EL.For example, relay DC is 220 V, DR has it’s isolated optical I/P , EL has 50 V drive DC. C onscious effort is to be put to keep all voltage contacts of relay, DR & EL isolated from each other In case any changes are to be made in terminal designation, Done/ Not done corresponding change in ferruling In each & every panel & Marshalling Boxes/Kiosks, CT & CVT OK/ NOT OK Circuits must be provided with Disconnecting stud type terminals 20% spare TB’s provided in all types OK/ NOT OK Close Interlock of CB: In case trip relay is energized, Close OK/ NOT OK command not forwarded. Normally, Manual Close command from CP must be in series with One set of NC contact of the Trip relay CB in OFF Condition Selective checking of Trip-CKT Supervision relay of all CB’s.by Opening wire from TC, one by One.Repeat the same with CB in On Condition Permissive Tripping command thr’ PLCC Main-I Main-II 1st CH. Return Time ………. mS ………. mS


No. CF/C&P/10/ R-3 DATED 01/04/2011

Doc No. D-2-01-03-01-03

viii ix x xi xii xiii

5.

2nd CH. Return Time ………. mS ………. mS If substantial difference noted in above, reason for the difference ………………. Any Prospect for reduction of Diff. in Time Yes/ No Hanging of RTU reported in Event logger Yes/ No Reporting of communication failure of each channel in SER Yes/ No Any data error encountered during isolator operation Yes/ No Suggestion for improvement………………………………………..

General

i ii

6.

Single point earthing must be ensured for CT&PT circuit In case of four CT scheme ensure summation of Main/Tie/ Reactor CTs secondary to input of relay/ meters


S.No.

1. 2. 3.

Yes/ No Yes/ No

Description

Status (Yes/ No)

Remarks (Record deficiencies, if any)






(Erection Agency)



No. CF/C&P/10/ R-3 DATED 01/04/2011


Doc No. D-2-01-03-01-03

Checks for PLCC Region:

Sub-Station:

Feeder Name: Date of testing: Direction: Cabinet No.

LOA No. : Make: Frequency: Eqpt Sr. No.

1.

General test i ii iii iv v vi vii

viii ix x

2.

End to end Return Loss Measured (Attach separate sheet of results) End to end attenuation Tests done (Att ach separate sheet of results) Composite loss (attenuation) measured for HF cable coupling device Composite loss and return loss on coupling device using dummy load Measurement of AF frequency response (end to end) for the entire 4Khz bandwidth for speech and tele-protection channels Measurement of Signal to Noise ratio with line energized condition. Transmission time for tele-protection and other data channels Observation of Tx/Rx levels (test tone) for each channel at both ends by sequential switching on/off parallel channels using dummy load and also with transmission line Observation of end to end and trunk dialing performance Observation of unwarranted commands sent & received during switchyard operations

Yes/ No Yes/ No Yes/ No Yes/ No Yes/ No Yes/ No Yes/ No Yes/ No

Yes/ No Yes/ No

Carrier SET Check List a. Power Supply (Voltage as applicable) i ii iii iv v

48 v POWER SUPPLY 60V POWER SUPPLY +12 v POWER SUPPLY (-)12V POWER SUPPLY +5V POWER SUPPLY


b. Ripple test i ii iii

+12 V Ripple test (-) 12 V Ripple test +5V Ripple test


c. Freq generation check i ii iii iv

System clock checked Tx carrier Hz checked Rx carrier Hz checked Pilot freq. checked



No. CF/C&P/10/ R-3 DATED 01/04/2011

Doc No. D-2-01-03-01-03

3.

Transmitter

a. b. c. d. e.

4.

AF signal level i Pilot ii Check Pressing test button iii Test tone checked Tx RF setting done Output Power/ Boosting checked Tx alarm threshold checked Tx alarm indication checked

OK/ NOT OK OK/ NOT OK OK/ NOT OK Yes/ No OK/ NOT OK OK/ NOT OK OK/ NOT OK

Receiver i ii iii iv v

5.

Standard AGC setting done Af rx level setting done AGC test done Remote Loop check done Rx alarm indication( interrupting RF Line)


Telephony i. a. b. ii. a. b. iii iv v vi a. b.

6.

TX Level Check 4 wire IN Checked 2Wire in Checked RX Level Check Feeding from Opposite Station 4 wire Out Checked at 600Ohm 4 wire Out Checked at 600Ohm Dialing Chanel Checked Service Telephone checked Frequency Response across 600 Ohm (Attach separate sheet of results) Tele-operation: TX Level Check Done Rx Level check done

OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK


Protection Coupler Check a. Measurements i ii iii iv

All LED Indicators Checked Transmit Level checked Boost ratio Measured Boost ratio……………………… Muting of Speech Checked

No. CF/C&P/10/ R-3 DATED 01/04/2011



Doc No. D-2-01-03-01-03

b. Command Transmission checking i

ii iii

iv v vi vii viii

7.

RX Trip A Command Transmission Time Command Prolongation Time Aux A Command Transmission Time RX Trip B Command Transmission Time Command Prolongation Time Aux B Command Transmission Time Same for Trip C & D Trip Counters checked All Alarms Checked Loop test Done End to End test Done

2. 3.

………..ms ………..ms ………..ms OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK


S.No.

1.

………..ms ………..ms ………..ms

Description

Status (Yes/ No)








(Erection Agency)



No. CF/C&P/10/ R-3 DATED 01/04/2011

Doc No. D-2-01-03-01-03

Sub-Station Automation System (SAS) Region:

Sub-Station:

Feeder Name: Date of testing: Direction: Cabinet No.

LOA No. : Make: Frequency: Eqpt Sr. No.

1.

Availability of Items i.

ii.

iii. iv.

2.

Check availability of all the IEDs, GPS Clock, Gateway, Computers & Servers, Periferals, Network Switches, Modems and various communication hardware etc. as per Scheme Check avaiability of all the orignal softwares for PC/ Servers (OS + Application Softwares), IEDs, Switches, Gateway etc. as per the scheme Check the originality/ authenticity of all the hardware & software items for POWERGRID approval. Check the validity of license of softwares/ hardware keys.

OK/ NOT OK

OK/ NOT OK


Communication Setup i ii

iii iv v vi vii viii ix x xi xii xiii xiv xv

Check laying & termination of optical fiber as per approved scheme. OK/ NOT OK Check the proper tagging of optical fiber cable for identifying the OK/ NOT OK origin and termination. Check the LAN switches for proper installation & configuration as OK/ NOT OK per scheme e.g. IP address is entered correctly, ports of Network switches are correctly configured as per requirement, satisfactory working of all the ports etc. Keep the records of all IP addresses. Check dual DC power supply to all Network switches. OK/ NOT OK Check all the PCs & printers are connected over Ethernet LAN and OK/ NOT OK functioning properly. Check the satisfactory working of dual LAN as per scheme OK/ NOT OK Check for the alarm if any link failure(fiber cut) OK/ NOT OK Check communication of all IEDs through Network switches as per OK/ NOT OK the allocated IP address. Check the functionality & running of original NMS software. OK/ NOT OK Check the NMS software is monitoring the healthiness of Network OK/ NOT OK switches/ IEDs. Check communication between GATEWAY & SAS PC. OK/ NOT OK Check the communication between GATEWAY and PLCC data OK/ NOT OK channel. Check the communication of each IED with Both SAS PCs OK/ NOT OK individually. Check communication of each IED with DR PC. OK/ NOT OK Check the availability of spare cores in the armoured fiber optic OK/ NOT OK cable as per specifications.

No. CF/C&P/10/ R-3 DATED 01/04/2011


Doc No. D-2-01-03-01-03

3.

Time Synchronization i ii iii iv

4.

Check proper installation and configuration of GPS and associated hardware like antenna etc Check the availability of Time Synchronization Signal in the LAN through SNTP Check the synchronizing of each IED /Server with GPS. Check for alarm in case of failure of time synchronizing


IED Setup

i ii iii

iv v vi vii viii ix x xi

5.

Check the availability of list of names of IEDs and their front/rear port address Check IP address of all IEDs correctly entered. Check the proper installation and configuration of all IEDs (as per their proprietary softwares) and Preparation of their ICD files for integration in the S/S SCD file. Check the GOOSE function(Analog/Binary) for each IEDs and correctness of the same. Check SLD in IED HMI for correctness of same as per approved drawing. Check each IED(for line/transformer/reactor/Bus-Bar/BCU) are correctly tested for every protection requirement of scheme. Check loading of setting through local as well as remote. Check availability of all setting address as per the relay setting received from CC-engg. Check the operation of protection system and subsequent alarm at remote Local/HMI. Check the availabilty of alarms/events as per the POWERGRID requirement. Check the Auto-downloading of DR Fault file in case of disturbance.



Interlocking & Logic Setup (Through concerned BCUs)

i

ii

Check configuration & working of all soft interlocks for CBs, Isolators, Earth Switches including Bus Isolators as per protection schemes. Check configuration & working of all soft logics for Synchronization (DLDB, LLDB, LLLB, DLLB), Voltage Selection, Protection Transfer for DMT, Auto-s equencing etc. as per protection schemes.


OK/ NOT OK

OK/ NOT OK

No. CF/C&P/10/ R-3 DATED 01/04/2011

Doc No. D-2-01-03-01-03

6.

SCADA Setup

xxx xxxi xxxii xxxiii xxxiv xxxv xxxvi xxxvii xxxviii xxxix xl xli xlii xliii xliv xlv xlvi xlvii xlviii xlix l li lii liii

Check the proper integration of all IEDs and their ICD files in the S/S SCD file. Check the building up of database as per approved point list Check the correctness of HMI SLD for all bays/ feeders in both SAS PCs. Check the correctness of operation of CB,Isolators &Tap changing operation through HMI SLD of both SAS PCs. Check that the status of CB,Isolators should change immediately in HMI after performing operation. Check raising of audio alarm with SCADA alarm state for each breaker opening operation at HMI. Check the PLCC,CB operation counters are correctly changing with operation. Check the blocking of operation of bay equipments in case of issue of PTW through both SAS HMIs. Check the availability of SLD of LT switchgear and operation of the same through local/remote. Check all measurement functions (Current,Voltage,MW,MVA) and their correctness in local/remote HMI. Check the availability of OTI, WTI readings of ICTs on HMI & correctness of same. Check the availability of voltage & current of both auxiliary DC systems sources . Check the DG alarm/trip & fire fightning signals are coming in SAS HMI. Check the monitoring of Kiosk AC/ kiosk temperature through both SAS HMI. Check the colour coding of measurement parameters (Voltage,current,MW,MVAr,f etc.) if the values increases above a pre-set value with generation of audio/visual alarm. Check colour coding of SLD i.e. energized section will be in one colour and un-energized section will be in different colour. Check supervision of each IED on HMI of SAS PCs. Check Hot-stand by function availability between the SAS PCs. Check after restoring of Master server, all the data must be transferred to Master server from slave server in a quick time as per HOT STAND By feature. Check there should not be missing of any events during transfer from both Main to STANDBY and STANDBY to Main. Check provision of auto data backup & storage of monthly data backup. Check the correctness of alarm list and event list and proper sequencing of alarms/events. Check weather all the events in event list are timely punched with milli second data. Check the alarm/events of Auxiliary system are included in alarm/event list.

No. CF/C&P/10/ R-3 DATED 01/04/2011

OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK OK/ NOT OK




Doc No. D-2-01-03-01-03

liv lv lvi lvii lviii lix lx lxi lxii

7.

Check that the SAS configuration tool should be password protected. Check for any error signal while operating/running any software or performing any operation on SAS PC. Check that basic training has been given to local operation staff so that in case of emergency they will be able to start the SAS PC in case of shut-down. Check there should be no interruption in availability test. Check the Acknowledged alarms should shift to acknowledge window & persisting alarms should be in red colour with blinking of the same. Check the colour code of the acknowledged but persisting alarm. Check the nomenclature of events and alarms for user friendliness. Check the availability of backup of latest version configuration for ICD, SCD files, IED basic configuration, HMI server database etc. Ensure creation of appropriate restore points for each workstation in the substation after completion of commissioning.




Trends & Reports Setup i ii

iii iv v

8.

Check all the operation formats are as per POWERGRID formats. Check the reports generated by SAS PC are as per the requirement like max. & min. readings of voltage, MW, MVAR, MVA, Frequency, current etc. for a 24 hour period. Check the reports/trends can be selected/filtered for any time period (datewise) specified by user. Check the availability of measurements reports at desired interval of (15, 30,45 & 60 minutes) & correctness of the same. Check the trend display for each parameter(MW,MVA,MVAr,f,V,I etc.) at any time and at a interval selected by user.



Remote Operation & RLDC reporting


Check that Gateway has been installed and configured properly and is working satisfactorily. Check the Gateway Configuration as per approved interoperability profile of RLDC. Check the healthiness of communication between Gateway and RLDC for both channels Verify the data transfer to RLDC by point to point checking as well as at local level through Protocol Analyser Check that the online perameters on local/remote SLD like current,voltage,MW,MVAr,frequency etc are getting updated. Check the operation of equipments/alarms/events for remote controlled ss. Check the satus of CBs & Isolators should be available at RLDC and if any link fails then alarm should be generated.



No. CF/C&P/10/ R-3 DATED 01/04/2011

Doc No. D-2-01-03-01-03

viii

ix

x

9.

If SAS S/S has to be remote controlled then check authenticity of operation from Local & remote end(i.e When control is in hand of RCC, all local operation should be blocked and vice versa) Check that in case of failure of one channel, changeover at remote end happens automatically and no interruption in data flow to Remote end occurs. Check for availability of final approved signal list for 101 communication with all details.

2. 3.

OK/ NOT OK

OK/ NOT OK


S.No.

1.

OK/ NOT OK

Description

Status (Yes/ No)







(Erection Agency)



No. CF/C&P/10/ R-3 DATED 01/04/2011


Pre Commissioning Procedures and Formats for Switchyard Equipments

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