Composite Insulators Rev 4

5/20/2018 Composite Insulators Rev 4

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Technical specification

STATNETT SF

NYDALEN ALL 33

0484 OSLO

NORWAY

Title

Composite insulator specification

Classification

Open

Document number

1527789

Number of pages + enclosures

22

Distribution

Rev Date Author/Doc. owner

Controlled Recommended Approved

4 2013-10-31Miroslav RadojiBoris Adum / BLE

Kjell ge Halsan /BLE

Faggruppe-L7 yvind Rue/D


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Composite insulator specificationREV: 3

2013-10-31

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Revisions

Rev. 4 - 31.10.2013 TL: Data sheet with requirements for insulators added. Connectionlength 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 slightlymodified.

03.03.2011 SB: Updated according to Statnetts specification template

01.11.2006. The insulators shall be delivered with protective covering. The compositeinsulator 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.............................................................. ............................................. 74.2.1 Handling and storage instructions .................................................................................................. 7

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

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

5 DESIGN REQUIREMENTS ......................................................................................................................... 8

5.1 IDENTIFICATION............................................................................................................................................. 85.2 END FITTINGS................................................................................................................................................ 8

5.3 END FITTING SEAL .......................................................................................................................................... 85.4 HOUSING OF THE COMPOSITE INSULATOR........................................................................................................... 85.5 COLOUR....................................................................................................................................................... 85.6 SHED DESIGN................................................................................................................................................ 8

5.7 GRADING RING REQUIREMENTS........................................................................................................................ 95.8 ARC PROTECTION........................................................................................................................................... 95.9 DIMENSIONAL REQUIREMENTS......................................................................................................................... 9

5.10 ELECTRICAL REQUIREMENTS........................................................................................................................ 95.11 MECHANICAL REQUIREMENTS............................................................... ..................................................... 10

6 TESTS .................................................................................................................................................... 10

6.1 GENERAL.................................................................................................................................................... 116.2 DESIGN TESTS.............................................................................................................................................. 11

6.3 TYPE TESTS................................................................................................................................................. 116.4 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 LANGUAGE AND UNITS ................................................................................................................................. 138.2 INFORMATION TO BE SUPPLIED WITH TENDER.................................................................................................... 138.3 INFORMATION TO BE SUPPLIED AT ORDER......................................................................................................... 14

ANNEX A - PRINCIPLE DRAWINGS .................................................................................................................. 15

PRINCIPLE DRAWING OF LINE POST INSULATOR FOR JUMPER LOOP SUPPORT (OUTER PHASE.................................................. 15PRINCIPLE DRAWING OF LONG-ROD INSULATOR FOR JUMPER LOOP SUPPORT (MID PHASE) ................................................... 16PRINCIPLE 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 BTABLES 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.................................................. 21TABLE 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 lineinsulators for use on Statnett's overhead power transmission system.

2 Normative references

Composite insulators shall be designed, manufactured and tested in accordance with the latestversions 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 erosionIEC 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 inpolluted conditions - Part 3: Polymer insulators for a.c. systems

IEC 61109 Insulators for overhead linesComposite suspension and tension insulators fora.c. systems with a nominal voltage greater than 1 000 V Definitions, testmethods 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 voltagegreater than 1000 V - Part 1: Standard strength classes and end fittings

IEC 61466-2 Composite string insulator units for overhead lines with a nominal voltagegreater than 1000 V - Part 2: Dimensional and electrical characteristics

IEC 61952 Insulators for overhead lines - Composite line post insulators for a.c. systemswith a nominal voltage greater than 1 000 V - Definitions, test methods andacceptance 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 criteriaIEC 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 andacceptance criteria

CIGRE 184 Composite Insulator handling guide. Cigr WG 22.03, Brochure 184, April2001

3 Definitions

The terms used in this specification are defined in the normative references. Additional

definitions are:


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Corona extinction voltage: the voltage at which corona extinction occurs during a testvoltage 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 includingintermediate metal parts along the length of the insulator (seeFigure 1).

Figure 1 - Definition of connection length

4 General requirementsThe supplier shall be fully responsible for his designs and their satisfactory performance inservice. Approval by Statnett does not relieve the supplier of responsibility for the adequacyof his design, dimensions and details. Only manufacturers approved by Statnett may offerinsulators.

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 hasbeen awarded. The drawings shall contain the following information and dimensions in metricunits:

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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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 theend fitting.

o)Insulator massp)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 Handl ing and assembly instruc t ions

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 resistancematerial.

4.2.1 Handling and storage instructions

Handling and storage of composite insulators shall be in accordance with Cigr compositeinsulator handling guide (Cigre brochure 184). Instructions shall cover at least the followingaspects:

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 insulatorsshall 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 thecorrect position.

4.3 Service experienc e

Documented evidence shall be submitted of the achieved service experience with the insulatordesign offered. This shall at least include details on numbers of insulators installed, life timeof the units and number of insulators removed from service.


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5 Design requirements

5.1 Identif ication

Each insulator shall be marked with thea) 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 ofthe insulator.

5.2 End fi t t ings

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

5.3 End fitt in g seal

The interface between the end fittings and housing, named the end fitting seal, shall from aweather proof seal. The supplier shall submit information to prove that the end fitting sealshall remain water tight for the useful life of the insulator. This shall include the followinginformation:

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 andfully 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 oraround 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 desig n

The shed design shall be according to IEC 60815Part 3 and the requirements as specified inthe 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.


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5.7 Grading ring requirements

Grading rings shall be designed and supplied to control the E-field along the sheath of theinsulator 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 themaximum system voltage and insulator assembly as shown in Annex A.

The grading ring and attachment design shall allow for the installation or removal of gradingrings while the insulator is installed on the transmission line.

The supplier shall provide proof, in the form of detailed E-field calculations, on the suitabilityof the supplied grading ring.

The grading ring design may incorporate the arc protection features for the insulator. It shallbe able to withstand the power arc current and duration specified in the project specificrequirements.

Grading rings shall be designed so that there will not be partial discharges from the ring to theinsulating material even in the case of severe pollution.

Grading rings shall be designed with a smooth surface in order to avoid corona discharges onthe surface of the grading ring.

5.8 Arc protect ion

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

design.

5.9 Dimension al requirements

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

5.10 Electrical requi remen ts

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


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5.11 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 and1.5 kN horizontally at the far end of the insulator (seeFigure 2).

6

3.0 kN

1.5 kN

Figure 2 - Illustration of Mechanical load

requirements


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Tests

6.1 General

The composite insulators shall be tested in accordance with IEC 61109 and IEC 61952 andthe provisions of this specification.

The supplier shall supply test certificates that verify that the insulator meets all requiredcharacteristics.

Statnett reserves the right to randomly select insulators for exit tests to verify that theinsulators conform to all the requirements of this specification and that the traceability of theinsulators is in order. In case of deficiencies the inspector is entitled to demand that a numberof 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 asdescribed 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 beingoffered. These may be items such as spacers to fix the core rod in a concentric position in thehousing, 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 IEC61109 with the following amendment:

The temperature at which the test is performed shall be -30o

C to -35o

C.Thermal-mechanical test: The thermal mechanical test shall be performed as described inthe 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 IEC62217 Annex B: Test at multiple stresses

The housing material shall successfully withstand the tracking and erosion test of IEC 60587at 4.5 kV for 6 hours (incline plane test).

6.3 Type tests

Corona and radio interference voltage:Corona and radio interference voltage (RIV) testsshall be performed on the composite insulator, with its grading ring and/or arcing protectiondevice according to Paragraph 14 of IEC 61284. The Test shall be performed according to theVoltage Method on the Tension Test arrangement.

The specified minimum corona extinction voltage is stated in the project specificrequirements.

At a voltage stress equivalent to the maximum operating voltage the RIV noise limit shall be60dB (1V/300) at a 500 kHz measurement frequency and reference atmospheric

conditions.


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6.4 Sampling tests

For the sampling tests the rules of IEC 61109 and IEC 61952 shall be followed with thefollowing amendments:

The sizes of these samples are indicated in the table below.Table 1 - Sample sizes

If not otherwise agreed with Statnett the tests listed below have to be performed in addition tothe tests specified in IEC 61109 or IEC 61952. Please quote the additional costs involved, ifany, 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 thespecified 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 ofthe SML. The verification is performed by cutting the insulator in sections at a maximuminterval 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 endfittings. 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 rejectioncriteria: 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 than10 degrees.

Lot size (N)Sample size

E1 E2

N 50 2 1

50 < N 100 3 2

100 < N 300 4 3

300 < N IEC 61109 IEC 61109


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7 Packing requirements

Each crate shall contain a maximum of 12 insulators. The packing of the composite insulatorshall 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 andquote addition cost for the covering pr insulator.

The requirements for wood packaging material and dunnage are based on the 2002 FAOInternational Standard for Phytosanitary Measures (ISPM) n 15. The following measures arerequired (Directive 2004/102/EC) for wood packaging material and dunnage entering Norwayfrom 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 ofuniquely identified documents, in the English language.

Dimensions and tolerances shall be in conformance to those specified in the relevantstandards. All dimensions shall be given in SI (metric) units.

8.2 Information to be supp l ied 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 referencesand test dates,

g)Design test reports,


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h)Type test reports,

i) Preliminary inspection and test plan, according to the quality assurance system of themanufacturer 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 supp l ied 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 ofthe 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 l ine post insulator for jum per loop sup port (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 suppo rt (mid ph ase)


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Princ ip le drawing of l ine post insulator for loop support in f jord cross ing towers

The phase conductor clamp is to be supplied together with insulators.

CONDUCTOR CLAMP


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Princ ip le drawing of sus pension and tension str ing composi te insulator


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Annex B Tables of requirements for insulators

Table of requirements for l ine post in sulator for jum per loop su ppo rt (outer ph ase)

TechnicalRequirements

Guaranteedvalues to befilled in by

manufacturer

1 Manufacturer Please specify

2 Manufacturer's type reference Please specify

3 Classification

(a) Application Suspension

(b) Housing material Silicone Based

(c) Color of housing Grey

4 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

Minimum Temperature -50 C

Maximum Temperature 40 C

Maximum Diurnal Variation 20 C

5 Mechanical Strength Requirements

(a) Specified Cantilever Load SCL 1,5 kN

(b) Specified Minimum Mechanical Failing Load SML 3,0 kN

6 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 (phase to earth) 290 kV (RMS)

7 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

8 Quantity


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Table of requirements for long -rod insulator for jumper loop supp ort (mid phase)


Guaranteedvalues to be

filled in bymanufacturer



3 Classification














(a) Specified Minimum Mechanical Failing Load SML Please specify







(a) Connecting Length and tolerance 4750 100 mm



(d) End Fittings Clevis-Clevis

8 Quantity


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Table of requi rements for l ine post insulator for loop sup port in f jord cross ing tow ers






3 Classification














(a) Specified Cantilever Load SCL 1,5 kN

(b) Specified Minimum Mechanical Failing Load SML 3,0 kN










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

Flange-Flange(see specification)

8 Quantity


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Table of requirements for suspensio n and tension str ing insulators






3 Classification


Tension











Maximum Diurnal Variation 20 C5 Mechanical Strength Requirements

(a) Specified Minimum Mechanical Failing Load SML (see tender either 160, 210, or300 kN))










(d) End FittingsIEC 60120 Designation Ball & Socket to comply withspecified mechanical requirements

Ball (at live end) -Socket

8 Quantity

Composite Insulators Rev 4

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