Field Quality Plan of EHV Power Cables

1

FIELD QUALITY PLAN - EHV POWER CABLES Manufacturer's Name & Address : KEI INDUSTRIES LIMITED, D-90,Okhla Industrial Area Phase 1,New Delhi-110020

Customer: BHEL Ref. Standard : IEC:60840 AND IEC:62067

Ref.: KEI Date:

S.No.

Component and Operation

Characteristics Checked

Category

1

2

3

4

Type of Check 5

On Laboratory test

one time

1 1.1 2

Before Start Of Installation Soil Thermal Resistivity Test

Thermal Resistivity

Extent of check

Reference Documents 7

6

8

9

10 KEI BHEL

Test Report

repeated

On every drum length

To demonstrate the integrity of outer-sheath of the cable with joints and terminations. Continuity of conductor

on site

repeated

on site

repeated

3.3 Absence of Cross Phasings 3.4 Insulation resistance test of both sections of the cable to be jointed 4 Test Before Commissioning 4.1 10 KV dc test for 1 minutes on outer sheath of completed phase 4.2 Coonductor Resistance test of each completed circuit

connections at joints To measure the ohmic value of the insulation under a direct voltage of great stability

on site on site

repeated repeated

on every drum length with joints and terminations after every joints and after full length after every joints Before and after installation of every joins

To demonstrate the integrity of outer-sheath of the cable of completed phase continuity of conductor at complete circuit

on site

repeated

on every completed phase

on site

one time

on completed circuit

on site

one time

on site

repeated

4.3 Capacitance Test


4.4 Cross bondings/single point bondings/both end bonding Tan delta test of each completed phase

Loss Measurement

on site

4.6

Ensuring with clients for minimum settings of their To ensure proper working of ckt in faulty condition on site proctections relays 4.7 Earth resistance test of each earth pit equipment To protect all earth pit equipment for lightening or faulton site 5 Final Commissioning Test The installation shall be tested with AC voltage 5.1 To check the healthiness of the circuit to be on site at power frequency voltage equals to 1.7Uo for commissioned

on site

To ensure proper working of ckt in faulty condition

on site

IEC 62067

one time

on each completed circuit

one time


one time

on each Las

a) 100 Amps with 8/20 micro sec wave shape. b) 10KA with 8/20 micro sec wave shape. Ensuring with clients for normal required settings of their protection relays

IEC 62067,Clause(10.10 )

one time

AC system voltage Uo for 24 hours to keep the cable on idle charge with minimum protection setting to protect the cable in 24 hours. Checking the healthiness and efficiency of Las

IEC 62067

Clause(12.4.5) of on each completed circuit 62067 IEC 62067 on each completed circuit as per clients

one time

OR

Checking of performance of LAs at following nominal discharge currents:

IEC 62067

on every completed phase

1 hour between each conductor and metallic sheath or AC system voltage Uo for 24 hours to keep the cable on idle charge with minimum protection settings to protect the cable in 24 hours

5.3

Agency

On Every Grade of soil

To demonstrate the integrity of the cable outer sheath On site

5.2

Format of record

Before and after installation of each cable length

2.1 10 KV DC Test for 1 minute on Outer Sheath 3 Before and after installation of joints and Termination 3.1 10 KV DC Test for 1 minute on Outer Sheath before and after joints and terminations 3.2 Cable Continuity Test/Low resistance measurement test

4.5

Acceptance Norms

one time on completed circuit

2



Ref.: KEI Date:

S.No.



Category

1

2

3

4

5.4 Checks of temporary reinstatements of roadways for settlement and after the subsidence has ceased, permanent reinstatement be completed. 6 In addition to the above, we have to prepare for the following additional performance test which are being demanded by the clients 6.1 The desired performance test shall comprise To check the healthiness of the complete cable system. keeping the commissioned cable system energized for at least for 7 consecutive days on continuous basis with the loads available at the time of carrying out the test. In case of failure, after due rectification, it shall be re-started for 7 seven continuous days. Still if it fails, the cable system is declared not suitable for any operation and shall be declared dead. In addition to the above, we have to prepare OURSLVES for the following additional tests which are likely to be demanded by the clients 7.1 If the facility at our works is available, it is ok. If not, we To Check the scc carrying capacity of metallic may have to equip ourselves to carry out the short circuit sheath as per specifications on metal sheath of cable to ensure that metal sheath withstands the specified short circuit current against each contract. 7.2 We need to evolve suitable procedure or test methodology for testing joint bays and manholes for withstanding live loads of 30T. 7.3 We need to evolve suitable procedure or test methodology for Joint Bay earthing for it`s effectiveness to discharge the fault currents. 7.4 Measurement of MOISTURE CONTENT in extruded insulation and screens:

Type of Check 5

Extent of check 6

one time

on site

on site

as per requirement

on complete cable system

7

The moisture content of the insulation and screens shall be measured using the Karl Fischer Titration method. Three measurements shall be taken from each of the two screens and insulation. < 150ppm of moisture should be detected in the extruded insulation. < 500ppm of moisture shall

be detected in the screens.

" on per phase

on site

on site

on site


Acceptance Norms

Format of record

Agency

8

9

10 KEI BHEL

3



Ref.: KEI Date:

S.No.



Category

1

2

3

4

7.5

Measurement of SCREEN PROTRUSIONS: The semiconducting conductor and insulation screens shall be examined on the water samples. The contact surface between the screen and the insulation shall be cylindrical, smooth and free from protrusions and irregularities which extend more than 0.03mm into the insulation.

The outer screen of the cable core shall be removed from a 0.5m sample length. The sample shall be rendered transparent by immersion in a suitable heated fluid. The screen shall be examined for the presence of screen defects. Measurement of cross-linking by product concentration in XLPE insulation:

Excessive by-product concentration adversely affects the electrical performance of the cable and could diffuse out of the cable core and pressurize external cable protection/accessories. The test is to be conducted using TGA (ThermoGravimetric Analyser) apparatus. A 20mg insulation sample is required. The test is to be conducted for 30 minutes at 150ºC. The % loss of weight of the sample is to be recorded. Five samples are to be taken, the result being the average of five tests.

Type of Check 5

Extent of check 6


Acceptance Norms

Format of record

Agency

8

9

10 KEI BHEL

4



Ref.: KEI Date:

S.No.



Category

1

2

3

4

7.6 Measurement of cross-linking by product concentration in XLPE insulation:

Excessive by-product concentration adversely affects the electrical performance of the cable and could diffuse out of the cable core and pressurize external cable protection/accessories. The test is to be conducted using TGA (ThermoGravimetric Analyser) apparatus. A 20mg insulation sample is required. The test is to be conducted for 30 minutes at 150ºC. The % loss of weight of the sample is to be recorded. Five samples are to be taken, the result being the average of five tests.

The cable is at a stable by-product level if:

The total weight changes if the test sample after a period of 30 minutes is less than 1.25% of the original sample weight. 7.7 XLPE Material Characterization: All insulating and semi-conducting XLPE materials used to manufacture all cables to be supplied, shall be identical to those used to manufacture the Type Test Cable. In order to demonstrate compliance, the contractor shall “finger print” samples from the Type Test Cable and all cables manufacture under the contract. The characterization shall include the following methods: 1. Fourier Transform Infrared Spectroscopy (FTIR) to characterize the insulation polymer. 2. Differential scanning Calorimetry to characterize the material processing. 3. Thermo gravimetric Analysis (TGA) on the incoming semiconducting material to characterize the carbon black content. 4. Cleanliness measurement on the incoming insulation material 5. Thermo gravimetric Analysis (TGA) on the incoming semiconducting material to characterize the carbon black content. Test 1 and 2 will be conducted on both ends of every dispatch drum. Tests 3,4,and 5 will be conducted on every batch of incoming material.

Type of Check 5

Extent of check 6


Acceptance Norms

Format of record

Agency

8

9

10 KEI BHEL

5



Ref.: KEI Date:

S.No.



Category

1

2

3

4

Type of Check 5

Extent of check 6


Acceptance Norms

Format of record

Agency

8

9

10 KEI BHEL

7.8 One-Piece Premoulded Joints and Three Piece Prefabricated Joints: The insulation and screening material used for all onepiece premouled joints and elastomeric stress cone components of three piece prefabricated joints shall be identical to those used to manufacture the Type Test accessories. The characterization of the insulation and screening material shall include :

1. Fourier Transform Infrared Spectroscopy (FTIR) to characterize the insulating polymer. 2. Cleanliness measurement on the incoming insulation material 3. DLA measurement of insulation at 90ºC. 4. Thermo gravimetric Analysis (TGA) on the incoming semiconducting material to characterize the carbon black content. The above tests will be carried out one joint in every ten manufactured for the contract. The following, additional tests, will be conducted on every one piece joint or elastomeric stress cone: 1. HV withstand test at 2Uo for 30 minutes, 2. Partial Discharge measurement at 2Uo. Discharge to be <10pC with background noise level of 2pC

Overlap

"

7.9 CORRECT preparation of AS-BUILT drawings which have a greater influence of functional guarantees extended by us in terms of retention amounts, bank guarantees etc

All routes shall be defined precisely, and shown in drawings at a scale of 1:500. The stable structures shall be indicated clearly as well as distances. The crossings with roads and underground installation shall be shown. Joint locations shall be identified clearly and sufficient sections views shall be provided where necessary. The dates of installation of cable joints, cable drum serial numbers, name of jointers, shall be included in the ASBUILT drawings. Cable section lengths shall also be given.

(For KEI Industries Lim

6

PLAN - EHV POWER CABLES

Remarks 11

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Remarks 11

8


Remarks 11

9


Remarks 11

10


Remarks 11

(For KEI Industries Limited)

Field Quality Plan of EHV Power Cables

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