Composite Insulators Rev 4

Technical specification STATNETT SF

Title

NYDALEN ALLÉ 33

Composite insulator specification

0484 OSLO NORWAY Classification

Document number

Open

1527789

Number of pages + enclosures

22

Distribution

Rev

4

Date

2013-10-31

Author/ Doc. owner

Controlled

Miroslav Radojčić Kjell Åge Halsan / Boris Adum / BLE BLE

Recommended

Approved

Faggruppe-L7

Øyvind Rue/D


REV: 3 2013-10-31

Revisions Rev. 4 - 31.10.2013 TL: Data sheet with requirements for insulators added. Connection length for long-rod insulators now specified. Corrected error in required SML in sect. 5.11. Rev. 3 - 13.01.2012 SB/MR: Complete specification revision. All chapters have been slightly modified. 03.03.2011 SB: Updated according to Statnett’s specification template 01.11.2006. The insulators shall be delivered with protective covering. The composite insulator colour shall be grey.

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Table of contents 1

SCOPE ..................................................................................................................................................... 5

2

NORMATIVE REFERENCES ....................................................................................................................... 5

3

DEFINITIONS ........................................................................................................................................... 5

4

GENERAL REQUIREMENTS ....................................................................................................................... 6 4.1 DRAWINGS ................................................................................................................................................... 6 4.2 HANDLING AND ASSEMBLY INSTRUCTIONS ........................................................................................................... 7 4.2.1 Handling and storage instructions .................................................................................................. 7 4.2.2 4.3

5

SERVICE EXPERIENCE ....................................................................................................................................... 7

DESIGN REQUIREMENTS ......................................................................................................................... 8 5.1 5.2 5.3 5.4 5.5 5.6 5.7 5.8 5.9 5.10 5.11

6

Assembly instructions ...................................................................................................................... 7

IDENTIFICATION ............................................................................................................................................. 8 END FITTINGS ................................................................................................................................................ 8 END FITTING SEAL .......................................................................................................................................... 8 HOUSING OF THE COMPOSITE INSULATOR ........................................................................................................... 8 COLOUR ....................................................................................................................................................... 8 SHED DESIGN ................................................................................................................................................ 8 GRADING RING REQUIREMENTS ........................................................................................................................ 9 ARC PROTECTION ........................................................................................................................................... 9 DIMENSIONAL REQUIREMENTS ......................................................................................................................... 9 ELECTRICAL REQUIREMENTS ........................................................................................................................ 9 MECHANICAL REQUIREMENTS.................................................................................................................... 10

TESTS .................................................................................................................................................... 10 6.1 GENERAL.................................................................................................................................................... 11 6.2 DESIGN TESTS.............................................................................................................................................. 11 6.3 TYPE TESTS ................................................................................................................................................. 11 6.4 SAMPLING TESTS.......................................................................................................................................... 12 6.4.1 Dry power frequency withstand test (E1) ...................................................................................... 12 6.4.2

Verification of minimum housing thickness (E1): .......................................................................... 12

6.4.3

Visual inspection (E1+E2) .............................................................................................................. 12

7

PACKING REQUIREMENTS ..................................................................................................................... 13

8

DETAILS OF THE INFORMATION REQUIRED ........................................................................................... 13 8.1 8.2 8.3

LANGUAGE AND UNITS ................................................................................................................................. 13 INFORMATION TO BE SUPPLIED WITH TENDER .................................................................................................... 13 INFORMATION TO BE SUPPLIED AT ORDER ......................................................................................................... 14

ANNEX A - PRINCIPLE DRAWINGS .................................................................................................................. 15 PRINCIPLE DRAWING OF LINE POST INSULATOR FOR JUMPER LOOP SUPPORT (OUTER PHASE .................................................. 15 PRINCIPLE DRAWING OF LONG-ROD INSULATOR FOR JUMPER LOOP SUPPORT (MID PHASE) ................................................... 16 PRINCIPLE DRAWING OF LINE POST INSULATOR FOR LOOP SUPPORT IN TOWERS FOR FJORD CROSSINGS.................................... 17 PRINCIPLE DRAWING OF SUSPENSION AND TENSION STRING COMPOSITE INSULATOR ........................................................... 18

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ANNEX B – TABLES OF REQUIREMENTS FOR INSULATORS .............................................................................. 19 TABLE OF REQUIREMENTS FOR LINE POST INSULATOR FOR JUMPER LOOP SUPPORT (OUTER PHASE) ........................................ 19 TABLE OF REQUIREMENTS FOR LONG-ROD INSULATOR FOR JUMPER LOOP SUPPORT (MID PHASE) ........................................... 20 TABLE OF REQUIREMENTS FOR LINE POST INSULATOR FOR FJORD CROSSING LOOP SUPPORT .................................................. 21 TABLE OF REQUIREMENTS FOR SUSPENSION AND TENSION INSULATORS ............................................................................ 22

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1 Scope This specification covers the design, manufacture, testing and supply of composite line insulators for use on Statnett's overhead power transmission system.

2 Normative references Composite insulators shall be designed, manufactured and tested in accordance with the latest versions and amendments of the following standards: IEC 60071-1 Insulation co-ordination - Part 1: Definitions, principles and rules IEC 60120

Dimensions of ball and socket couplings of string insulator units

IEC 60471

Dimensions of clevis and tongue couplings of string insulator units

IEC 60687

Electrical insulating materials used under severe ambient conditions - Test methods for evaluating resistance to tracking and erosion

IEC 60815-1 Selection and dimensioning of high-voltage insulators intended for use in polluted conditions - Part 1: Definitions, information and general principles IEC 60815-3 Selection and dimensioning of high-voltage insulators intended for use in polluted conditions - Part 3: Polymer insulators for a.c. systems IEC 61109

Insulators for overhead lines – Composite suspension and tension insulators for a.c. systems with a nominal voltage greater than 1 000 V – Definitions, test methods and acceptance criteria

IEC 61284

Overhead lines - Requirements and tests for fittings

IEC 61466-1 Composite string insulator units for overhead lines with a nominal voltage greater than 1000 V - Part 1: Standard strength classes and end fittings IEC 61466-2 Composite string insulator units for overhead lines with a nominal voltage greater than 1000 V - Part 2: Dimensional and electrical characteristics IEC 61952

Insulators for overhead lines - Composite line post insulators for a.c. systems with a nominal voltage greater than 1 000 V - Definitions, test methods and acceptance criteria

IEC 62073

Guidance on the measurement of wettability of insulator surfaces

IEC 62217

Polymeric insulators for indoor and outdoor use with a nominal voltage greater than 1 000 V - General definitions, test methods and acceptance criteria

IEC 61952

Insulators for overhead lines - Composite line post insulators for A.C. systems with a nominal voltage greater than 1 000 V - Definitions, test methods and acceptance criteria

CIGRE 184 Composite Insulator handling guide. Cigré WG 22.03, Brochure 184, April 2001

3 Definitions The terms used in this specification are defined in the normative references. Additional definitions are: Page 5 of 22


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Corona extinction voltage: the voltage at which corona extinction occurs during a test voltage series. Connecting length: refers to the shortest distance between fixing points of the live and earthed metal ware, ignoring the presence of any stress control rings, but including intermediate metal parts along the length of the insulator (see Figure 1).

Figure 1 - Definition of connection length

4 General requirements The supplier shall be fully responsible for his designs and their satisfactory performance in service. Approval by Statnett does not relieve the supplier of responsibility for the adequacy of his design, dimensions and details. Only manufacturers approved by Statnett may offer insulators. The manufacturer is responsible for suppling bolts for clevis and flange end fittings. 4.1

Drawings

Each tender shall include one copy of all the detail and assembly drawings of the composite insulator offered. The final versions of these drawing shall be submitted when the tender has been awarded. The drawings shall contain the following information and dimensions in metric units: a) Identification Marking b) Manufacturers Catalogue number c) Maximum system voltage d) Dry lightning impulse withstand voltage e) Wet switching impulse withstand voltage f) Wet power frequency withstand voltage g) Specified mechanical load (SML) h) Coupling method, dimensions and IEC designation i) Housing material description j) Colour of housing k) Minimum arcing distance l) Minimum creepage distance m) Connecting length and tolerance

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REV: 3 2013-10-31

n) Position and dimensions of the corona ring(s) if present. This shall include the tube diameter, ring diameter and its position with respect to the end fitting. o) Insulator mass p) Minimum diameter over sheath q) Shed diameter of both the large and small sheds r) Shed spacing s) Maximum diameter over insulating part t) Core diameter u) Core material description v) Routine test load (RTL) 4.2

Handling and assembly instructions

The supplier shall provide handling, storage and assembly instructions together with the offer, in one or more documents. Instruction shall be attached to each crate in a weather resistance material. 4.2.1

Handling and storage instructions

Handling and storage of composite insulators shall be in accordance with Cigré composite insulator handling guide (Cigre brochure 184). Instructions shall cover at least the following aspects: a) Required actions on receiving insulators, b) Instructions for unpacking, c) Instructions for storage, d) Instructions for transportation, e) Instructions for field handling. 4.2.2

Assembly instructions

Instructions for assembly and attachment of corona (or grading) rings to composite insulators shall contain all necessary information for correct assembly of rings and include at least: a) Assembly procedure b) Tools required c) Control operations that shall be performed to verify that the ring is located in the correct position. 4.3

Service experience

Documented evidence shall be submitted of the achieved service experience with the insulator design offered. This shall at least include details on numbers of insulators installed, life time of the units and number of insulators removed from service. Page 7 of 22


REV: 3 2013-10-31

5 Design requirements 5.1

Identification

Each insulator shall be marked with the a) Name or trademark of the manufacturer b) Catalogue number c) The year and month of manufacture d) The SML e) A unique serial number or batch identification. These marks shall be legible and permanently readable for the duration of the service life of the insulator. 5.2

End fittings

The end fittings of the insulators shall be connected to the core by crimping. All ferrous material, except stainless steel, shall be hot-dip galvanized. 5.3

End fitting seal

The interface between the end fittings and housing, named the end fitting seal, shall from a weather proof seal. The supplier shall submit information to prove that the end fitting seal shall remain water tight for the useful life of the insulator. This shall include the following information: a) Details of the end fitting seal design b) Years of service experience obtained with this particular design 5.4

Housing of the composite insulator

To prevent moisture ingress from the environment, the core shall be totally encapsulated and fully sealed, from live to earth ends, by the insulator housing. The housing shall have a minimum thickness of 3 mm over the core at any point along or around the insulator. The housing material is specified in the Schedule of requirements. 5.5

Colour

The colour of the composite insulators is in the Schedule of requirements 5.6

Shed design

The shed design shall be according to IEC 60815 – Part 3 and the requirements as specified in the Schedule of requirements. The Minimum Ratio of Shed Spacing to Shed Projection shall be 0,8. The shed spacing shall be more than 35 mm. Page 8 of 22


5.7

REV: 3 2013-10-31

Grading ring requirements

Grading rings shall be designed and supplied to control the E-field along the sheath of the insulator housing to below 4.5 kV/cm under dry and clean conditions. The E-field shall not exceed 3.5 kV/cm on the end fitting seal. The design of the ring shall be based on the maximum system voltage and insulator assembly as shown in Annex A. The grading ring and attachment design shall allow for the installation or removal of grading rings while the insulator is installed on the transmission line. The supplier shall provide proof, in the form of detailed E-field calculations, on the suitability of the supplied grading ring. The grading ring design may incorporate the arc protection features for the insulator. It shall be able to withstand the power arc current and duration specified in the project specific requirements. Grading rings shall be designed so that there will not be partial discharges from the ring to the insulating material even in the case of severe pollution. Grading rings shall be designed with a smooth surface in order to avoid corona discharges on the surface of the grading ring. 5.8

Arc protection

The insulator and all fittings in the configuration in which they shall be used shall be resistant to the consequences of a power arc as described in lEC 61467. If, in the opinion of the manufacturer, arc protection devices are required to guarantee enough durability, then this shall be stated on the datasheet. The arc protection may be incorporated in the grading ring design. 5.9

Dimensional requirements

The insulator shall be dimensioned according to the project specific requirements. 5.10

Electrical requirements

The electrical characteristics shall be as specified in the project specific requirements.

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5.11

REV: 3 2013-10-31

Mechanical requirements

The mechanical requirements shall be as specified in the project specific requirements. For composite suspension and tension insulators a curve showing the load - time strength and damage limit of the insulators shall be submitted with the offer. The composite line post insulator shall withstand a mechanical load of 3.0 kN vertically and 1.5 kN horizontally at the far end of the insulator (see Figure 2).

6

1.5 kN

3.0 kN Figure 2 - Illustration of Mechanical load requirements

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REV: 3 2013-10-31

Tests 6.1

General

The composite insulators shall be tested in accordance with IEC 61109 and IEC 61952 and the provisions of this specification. The supplier shall supply test certificates that verify that the insulator meets all required characteristics. Statnett reserves the right to randomly select insulators for exit tests to verify that the insulators conform to all the requirements of this specification and that the traceability of the insulators is in order. In case of deficiencies the inspector is entitled to demand that a number of insulators in the batch are retested. A test report shall be presented to the Client at the final day of testing. 6.2

Design tests

Test specimens and preliminary tests: The test specimens for all the design tests shall be as described in the IEC 61109 and IEC 61952 with the following amendment: The tested samples shall also include all the design features present on the insulator being offered. These may be items such as spacers to fix the core rod in a concentric position in the housing, joint sealant rings or other housing joints perpendicular to the core that may not be present on the shorter insulators of the same product line. Sudden load release test: The sudden load release test is performed as described in the IEC 61109 with the following amendment: The temperature at which the test is performed shall be -30 oC to -35 oC. Thermal-mechanical test: The thermal mechanical test shall be performed as described in the IEC 61109 with the thermal cycle amended as follows: Each 24 h thermal cycle has two temperature levels with a duration of at least 8 h, one at +45oC  5 K, the other at -45oC  5 K. Test of housing: tracking and erosion test: The insulator shall be tested according to IEC 62217 Annex B: “Test at multiple stresses” The housing material shall successfully withstand the tracking and erosion test of IEC 60587 at 4.5 kV for 6 hours (incline plane test). 6.3

Type tests

Corona and radio interference voltage: Corona and radio interference voltage (RIV) tests shall be performed on the composite insulator, with its grading ring and/or arcing protection device according to Paragraph 14 of IEC 61284. The Test shall be performed according to the Voltage Method on the Tension Test arrangement. The specified minimum corona extinction voltage is stated in the project specific requirements. At a voltage stress equivalent to the maximum operating voltage the RIV noise limit shall be 60dB (1V/300) at a 500 kHz measurement frequency and reference atmospheric conditions. Page 11 of 22


6.4

REV: 3 2013-10-31

Sampling tests

For the sampling tests the rules of IEC 61109 and IEC 61952 shall be followed with the following amendments: The sizes of these samples are indicated in the table below. Table 1 - Sample sizes

Sample size

Lot size (N)

E1

E2

2

1

50 < N  100

3

2

100 < N  300

4

3

N  50

300 < N

IEC 61109 IEC 61109

If not otherwise agreed with Statnett the tests listed below have to be performed in addition to the tests specified in IEC 61109 or IEC 61952. Please quote the additional costs involved, if any, for following sample tests. 6.4.1

Dry power frequency withstand test (E1)

A dry power frequency test shall be performed on sample E1 before the verification of the specified mechanical load, according to clause 9.2.3 of IEC 62217:2005. 6.4.2

Verification of minimum housing thickness (E1):

The minimum thickness of the housing shall be verified on sample E1 after the verification of the SML. The verification is performed by cutting the insulator in sections at a maximum interval of 400 mm. The cuts shall be performed perpendicular to the core rod, midway between two sheds. A cut shall also be made on the two sheath portions closest to the end fittings. The housing thickness is then measured at the thinnest point for each cut. 6.4.3

Visual inspection (E1+E2)

A visual inspection shall be made on each insulator with the following additional rejection criteria: An insulator is rejected when: a) The mould line or flashing is higher than 1 mm above the shed surface. b) The depth of cavities is over 1 mm. c) There are cracks at the root of the sheds next to the fittings d) There are cracks in the metal fitting e) There is a separation or lack of sealant at the shed/metal fitting interface f) The axial misalignment of the metal fitting to the core rod is greater than 2 degrees g) The rotational misalignment of one metal fitting with respect to the other greater than 10 degrees.

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REV: 3 2013-10-31

7 Packing requirements Each crate shall contain a maximum of 12 insulators. The packing of the composite insulator shall be adequate for the handling and transport to the delivery destination. The walls of the crate shall be sufficiently solid to prevent the entry of rodents. Separate items or accessories, if packed with the insulators, must be properly secured within the crate. Please describe your protection method, installation of protection and type of material and quote addition cost for the covering pr insulator. The requirements for wood packaging material and dunnage are based on the 2002 FAO International Standard for Phytosanitary Measures (ISPM) n° 15. The following measures are required (Directive 2004/102/EC) for wood packaging material and dunnage entering Norway from all non EU countries (except Switzerland):  the wood must be either heat treated or fumigated with methyl bromide, in line with ISPM15 procedures;  the wood must be officially marked with the ISPM15 stamp;  all wood packaging material has to be debarked.

8 Details of the information required 8.1

Language and Units

All correspondence, literature, drawings and markings shall be submitted in the form of uniquely identified documents, in the English language. Dimensions and tolerances shall be in conformance to those specified in the relevant standards. All dimensions shall be given in SI (metric) units. 8.2

Information to be supplied with tender

The following information shall be submitted with the tender: a) Preliminary drawing of the complete insulator inclusive corona ring, b) Material of the end fitting, c) Fixing materials (bolts, nuts, …), d) Details of grading rings:  Ring diameter,  Pipe diameter,  Attachment details,  Position relative to the end fittings, e) Garantueed values as per schedule of requirements, f) An overview of the relevant design and type test reports containing report references and test dates, g) Design test reports, Page 13 of 22


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h) Type test reports, i) Preliminary inspection and test plan, according to the quality assurance system of the manufacturer and the requirements of this specification, j) Instructions for handling and storage of the composite insulators k) Instructions for assembly and attachment of corona (grading) rings l) Representative (correct tower configuration) results of E-field calculations m) Documentation regarding treatment of wooden crate (chemical, thermal, gas etc.). n) Power arc test results o) Completed schedule of requirements 8.3

Information to be supplied at order

The following information shall be submitted within two weeks after contract award: a) Final drawings, including all definite data b) Final quality inspection and test plan, according to the quality assurance system of the manufacturer and the requirements of this specification The following information shall be included in each packed crate with insulators: a) Final instructions for handling and storage of the composite insulators b)

Final installation instructions for the assembly and installation of the corona rings

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Annex A - Principle drawings Principle drawing of line post insulator for jumper loop support (outer phase)

Note that the flange holes shall be in line with tongoue holes, as shown in the drawing.

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Principle drawing of long-rod insulator for jumper loop support (mid phase)

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Principle drawing of line post insulator for loop support in fjord crossing towers The phase conductor clamp is to be supplied together with insulators.

CONDUCTOR CLAMP

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Principle drawing of suspension and tension string composite insulator

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Annex B – Tables of requirements for insulators Table of requirements for line post insulator for jumper loop support (outer phase) Technical Requirements

1

Manufacturer

Please specify

2

Manufacturer's type reference

Please specify

3

Classification

4

(a) Application

Suspension

(b) Housing material

Silicone Based

(c) Color of housing

Grey

Guaranteed values to be filled in by manufacturer

Operating conditions (a) System Maximum Voltage Um

420 kV

(b) Power Arc Rating

30 kA; 1 s

(c) Type of environment

Marine

(d) Height above sea level

< 1000 m

(e) Operating Temperature

5

6

Minimum Temperature

-50 °C

Maximum Temperature

40 °C

Maximum Diurnal Variation

20 °C

Mechanical Strength Requirements (a) Specified Cantilever Load

SCL

1,5 kN

(b) Specified Minimum Mechanical Failing Load

SML

3,0 kN

Electrical Strength Requirements (a) Dry Lightning Impulse Withstand

(at Sea Level)

1425 kV

(b) Wet Switching Impulse Withstand

(at Sea Level)

1050 kV

(c) Wet Power Frequency Withstand

(at Sea Level)

630 kV

(d) Minimum Corona Extinction Voltage 7

8

(phase to earth)

290 kV (RMS)

Dimensions and Clearances (a) Connecting Length and tolerance

Please specify

(b) Minimum Creepage Length

7200 mm

(c) Minimum flash over length

3000 mm

(d) End Fittings

Flange-Tongue

Quantity

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Table of requirements for long-rod insulator for jumper loop support (mid phase) Technical Requirements

1

Manufacturer

Please specify

2


Please specify

3

Classification

4

(a) Application

Suspension


Silicone Based


Grey



420 kV


30 kA; 1 s


Marine


< 1000 m


5

Minimum Temperature

-50 °C

Maximum Temperature

40 °C


20 °C

Mechanical Strength Requirements (a) Specified Minimum Mechanical Failing Load

6

8

Please specify


(at Sea Level)

1425 kV


(at Sea Level)

1050 kV


(at Sea Level)

630 kV


SML

(phase to earth)

290 kV (RMS)


4750 ± 100 mm


7200 mm


3000 mm

(d) End Fittings

Clevis-Clevis

Quantity

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Table of requirements for line post insulator for loop support in fjord crossing towers Technical Requirements

1

Manufacturer

Please specify

2


Please specify

3

Classification

4

(a) Application

Suspension


Silicone Based


Grey



420 kV


30 kA; 1 s


Marine


< 1000 m


5

6

Minimum Temperature

-50 °C

Maximum Temperature

40 °C


20 °C

Mechanical Strength Requirements (a) Specified Cantilever Load

SCL

1,5 kN

(b) Specified Minimum Mechanical Failing Load

SML

3,0 kN


(at Sea Level)

1425 kV


(at Sea Level)

1050 kV


(at Sea Level)

630 kV


8

(phase to earth)

290 kV (RMS)


Please specify


7200 mm


3000 mm

(d) End Fittings (Conductor clamp to be supplied with insulator)

Flange-Flange (see specification)

Quantity

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Table of requirements for suspension and tension string insulators Technical Requirements

1

Manufacturer

Please specify

2


Please specify

3

Classification (a) Application


Suspension Tension

4


Silicone Based


Grey


420 kV


30 kA; 1 s


Marine


< 1000 m


5

Minimum Temperature

-50 °C

Maximum Temperature

40 °C


20 °C

Mechanical Strength Requirements (a) Specified Minimum Mechanical Failing Load

6

8

(see tender – either 160, 210, or 300 kN))


(at Sea Level)

1425 kV


(at Sea Level)

1050 kV


(at Sea Level)

630 kV


SML

(phase to earth)

290 kV (RMS)


Please specify


7200 mm


3000 mm

(d) End Fittings IEC 60120 Designation Ball & Socket to comply with specified mechanical requirements

Ball (at live end) Socket

Quantity

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Composite Insulators Rev 4

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