2. Fittings & Accessories for Overhead Line

8/10/2019 2. Fittings & Accessories for Overhead Line

http://slidepdf.com/reader/full/2-fittings-accessories-for-overhead-line 1/21

TRANSMISSION TECHNICAL SPECIFICATION

TENAGA NASIONAL BERHAD

275kV & 132kV TRANSMISSION LINE FITTINGS AND ACCESSORIES FOR OVERHEAD LINE

DOC. NO. : TTS-LN-FTNES Revision No. : 0 Date : 1 June 2011 of 21

Printed from EDMS System

275 KV AND 132 KVFITTINGS AND ACCESSORIES FOR OVERHEAD LINE

Table of Contents

Item Description Page

1.0 GENERAL 2

2.0 STANDARDS 23.0 DRAWINGS 3

3.1 DRAWING(S) AND DOCUMENT(S) TO BE SUBMITTED DURING TENDER 33.2 DRAWING(S) AND DOCUMENT(S) TO BE SUBMITTED FOR APPROVAL 3

4.0 INSULATOR FITTINGS 4

4.1 SUSPENSION CLAMPS 5

4.2 ARCING HORNS 5

4.3 SPECIAL DESIGN REQUIREMENT FOR MONOPOLE TOWERS 6

5.0 CONDUCTOR FITTINGS AND ACCESSORIES 7

5.1 EARTHWIRE SETS 8

5.2 ARMOUR RODS 8

5.3 DEAD-ENDS 8

5.4 MID-SPAN JOINTS 9

5.5 REPAIR SLEEVES 9

5.6 ACSR CONDUCTOR COMPRESSION FITTINGS 9

5.7 SPACER DAMPERS AND RIGID SPACER 9

5.8 ALLOCATION OF SPACER DAMPERS 11

5.9 COUNTER-WEIGHTS 12

5.10 JOINT COMPRESSORS 12

5.11 ALUMINIUM COPPER CONNECTORS 12

5.12 EARTHWIRES 13

5.13 AIR NAVIGATION OBSTRUCTION MARKING AND LIGHTING 13

6.0 INSPECTION AND TESTING 16

6.1 TEST AT MANUFACTURE’S WORK 16

6.1.1 SUMMARY OF TESTS AT WORKS 16

6.1.2 INSULATOR AND EARTHWIRE FITTINGS INCLUDING SUSPENSIONCLAMPS 16

6.1.3 CONDUCTOR FITTINGS 17

6.1.4 SPACER, VIBRATION DAMPERS AND SPACER DAMPERS 17

7.0 TEST DURING ERECTION 20

7.1 CONDUCTOR AND EARTHWIRE JOINT TESTS 20








1.0 GENERAL

Fittings shall be made to suit the types of insulators and phase conductors. The fittingsshould be suitable for porcelain, toughened glass or composite type. The phase

conductors and earthwires shall be of ACSR type and/or OPGW type respectively.

Details of the types, dimensions and arrangements of insulators, phase conductors andearthwires to be used in the project are as given in the Technical Schedule, Section 3 ofVolume 1. The design of all fittings shall avoid sharp corners or projections which wouldproduce high electrical stresses in service. All fittings shall satisfy the corona, radio &television interference voltage and audible noise limits as set out in the TechnicalSchedule, Section 3 of Volume 1.

The design of adjacent metal parts and mating surfaces shall be such as to preventcorrosion of the contact surfaces and to maintain good electrical contact under serviceconditions. It is of prime importance that all fittings be designed to give good long-termperformance. The Tender must include details of the offered fittings as the following:

a) Test Certificates showing the results of accelerated ageing and other testscarried out on the offered items.

b) Details of history of supply and performance records of similar fittings suppliedto other major electricity supply utilities.

Each fitting component shall be stamped with distinguishing numbers or letterscorresponding to those used on the approved working drawings. All steel componentsshall be hot dip galvanised. The marks are to be stamped prior to galvanising andshall be clearly legible after galvanising.

Where fitting components are to be supplied as sub-assemblies, only one mark perassembly is required.

2.0 STANDARDS

The design, manufacturing and testing of the fittings shall be carried out in accordancewith the provision in the latest revision British Standards (BS), or equivalent MalaysianStandards (MS) or IEC Standard.

BS 3288-1 :1997 - Insulator and conductor fittings for overhead power linesBS 3288-2 :1990 - Specification for a range of fittingsBS 3288-3 :1989 - Dimension of ball and socket coupling of string insulator unitBS 3288-4 :1989 - Locking devices for dimension of ball and socket coupling of

string insulator unit: dimensions and testIEC 61854 (1998) - Requirements and Test for spacersIEC 61897 (1998) - Requirements and tests for Stockbridge type aeollian

vibration dampersIEC 61284(1997) - Requirements and test for fittingsBS EN 1562(1997)

- Malleable Iron Castings

BS EN ISO 1461(1999)

- Hot dip galvanised coatings on iron and steel articles








BS 970 : (1996) - Forged SteelBS EN 1563 :(1997)

- Iron castings with spheroidal or modular graphite (ductile)

BS EN 12163:(1998)

- Copper and copper alloys, Table 8 - for chemical compositionand mechanical properties of phosphor bronze for pins orlocking devices

BS EN 1561 :(1997)

- Grey iron castings

BS ISO 262 :(1998)

- ISO metric hexagon bolts and nuts

IEEE Paper No 31CP65-156

- Standardization of conductor vibration measurement

Standards equal or better than the standards referred above are acceptable.

Any discrepancies between such Standards and those specified above shall be clearlyindicated by the Contractor. The Employer reserves the right to have the fittings offered

by the Contractor tested to the Standards mentioned in the Specification. If theContractor offers fittings made to an alternative Standard than those mentioned aboveand fail to meet the technical requirement as mentioned in the Specification as well asin the Schedule; the fittings thus offered shall be rejected. The Contractor is thenrequired to replace the rejected fittings with the approved type at no extra cost to theEmployer.

3.0 DRAWINGS

3.1 DRAWING(S) AND DOCUMENT(S) TO BE SUBMITTED DURING TENDER

The following drawing(s) shall be submitted together with the tender:

(i) General arrangement(ii) Full assembly and component drawing(iii) Type Test reports

3.2 DRAWING(S) AND DOCUMENT(S) TO BE SUBMITTED FOR APPROVAL

Subsequent to the award of the contract, the following drawing(s) and documentsshall be submitted for approval :

(i) General arrangement(ii) Full assembly and component drawings(iii) All test reports

The drawing(s) shall clearly shows the following information:

(a) Dimensions and tolerances;

(b) Material description, mass, quantity, minimum UTS and fabrication details;

(c) Supplier’s catalogue numbers;








(d) Location and description identification markings.

(e) Electrical clearances details

Detail drawings of the spacer-dampers and all components shall include the followinginformation: -

(a) Dimensions and tolerances for all parts and the assembly to metric units.(b) Material fabrication details including any weld details, specified finishes and

coatings.(c) Catalogue or part numbers for each component part and the total assembly.(d) Assembly drawing shall include: -

Installation instruction.

• Designed installation torque recommended for the bolt.

• Withstand torque that may be applied to the bolt without failure to thecomponent parts.

• Weight of assembly.

Note : Drawings may be supplied in an electronic *.dxf format.

4.0 INSULATOR FITTINGS

The types of insulator fittings to be provided under the Contract are described below.The following definitions are given for the descriptions used in Schedule H of Volume 3 and thereafter in the Contract :

a) Fittings for Normal Suspension Set.

Comprising all fittings required between the tower and the complete phaseconductor, including the shackle for connection to the tower, and the suspensionclamps for connection to the conductors.

b) Fittings for Jumper Suspension Set.

Similar to above except the suspension clamps shall be of 50 kg weightclamps. The costs of jumper suspension insulator sets shall be included in therates for the supply and erection of the relevant tower.

c) Fittings for Normal Tension Set.

Comprising all fittings required between the tower and the complete phaseconductors including the shackle for connection to the tower and the dead-endclamps for connection to the conductors. Dead-ends shall be complete withbolted jumper terminals.








d) Fittings for Light Duty Tension Sets.

Similar to (c) above, except that the arcing horns shall be capable ofadjustments to the gap distances required. For inverted light duty tension sets,turnbuckle adjusters shall be provided.

The fittings for all tension sets may include earth end extension links as required toachieve the minimum clearances laid down in the Specification. Earth end extensionlinks shall comprise one pair of cranked link plates and one pin complete with washerand retaining pin providing an extension of 150 mm per link. All shackles used shall beof the bow type. The shackle pin shall be secured with washer, nut and locked bymeans of a split pin. The Contractor shall indicate the actual pin diameters of thefittings.

For normal duplex or triplex conductor tension strings, sag adjusters shall be provided.The range of adjustments shall be approximately 300mm of increment not greater than

13mm. At the end of the Maintenance Period there shall be not less than ± 75mm of thelinear adjustment available. Light duty tension sets at the lower ends of slack spansshall be provided with turnbuckle adjusters. Suitable yoke plates shall be fitted whereduplex conductor downleads are to be fitted to light duty tension sets.

Adequate bearing area between fittings shall be provided and "point" and "line" contactsshall be avoided.

Bolts and nuts shall be in accordance with the appropriate Clauses of the Specificationand shall be locked in an approved manner. Split pins for securing attachment of fittingsof insulator sets shall be of stainless steel and shall be backed by washers of anapproved size and gauge. All insulator strings shall be attached to crossarms by meansof shackles. Hooks shall not be used. Fittings shall comply with BS3288:(1997) or MSequivalent.

4.1 SUSPENSION CLAMPS

Suspension clamps shall be made of cast aluminium alloy and forged steel. The clampshall be free to pivot in the vertical plane along the conductor with its axis located at thecentre of the conductor. The complete conductor shall be permitted to slip at a loadlower than the breaking load of the conductor. The conductor-supporting groove shallbe curved at its ends in the vertical plane to a radius of 150mm and for a sufficientdistance to allow for the conductor leaving the clamp at an angle of 20 degrees to thehorizontal.

The mouth of the supporting groove shall be slightly flared in plan. The grooves in theclamping piece or pieces shall be bell-mouthed at each end and all conductor grooves

and bell-mouths shall be smooth and free from waves, ridges or other irregularities.Particular attention shall be paid to the design of the clamps to comply with therequirements on corona, radio and television interference and audible noise limits.

4.2 ARCING HORNS

All insulator sets shall be fitted with line end arcing horns. Earth-end arcing horns shallalso be fitted as described in this Clause, and provisions shall be made on all sets for








their possible future installation. The design of the arcing horns shall be such as toobviate damage to clamps and conductors, and to prevent cascading over the line endinsulator units when flashover occurs. The amount of lift and general shape shall at thesame time give maximum values of impulse flashover withstand voltage consistent withthe above provisions. In particular the lift of line end arcing horns shall be such that their

points extend beyond the line end insulator disc.

The arcing horns shall not be attached to the insulator pins or caps.

Any special tests considered necessary to prove the correct setting of arcing hornfittings shall be carried out at the manufacturer's works at no additional cost to theEmployer.

Details of the arcing horns are as the following:

a) Normal Suspension Insulators

Double point line end arcing horns shall be fitted so as to provide a verticalarc path on each side of the insulator string. The arcing horns shall be strongenough to support with adequate security a person weighing up to 90kgstanding on the extremities.

For 275kV circuits, the line end arcing horns shall be of double-point racquet-type and shall be arranged in a vertical plane at right angles to that of theconductors. These shall have a sufficient reach to ensure that a direct flashoverin air from the tower steelwork shall terminate on the horn, and not on the

conductors at the angle of swing of 15°.

b) Normal Tension Insulators

Single point line end arcing horns shall be fitted so as to provide a horizontalarc path above the insulator strings. The normal tension sets for 275kVcircuits shall be provided with a single point racquet-type line end arcing horn.

c) Light Duty Tension Insulators

Upright light duty tension insulators for use at the upper end of the slack spansbetween the terminal tower and the substation gantry shall be fitted with singlepoint line end arcing horns similar to those used on the relevant normal tensioninsulators. The inverted light duty tension insulator sets at the lower end of slackspans shall be fitted with only line-end arcing horns.

4.3 SPECIAL DESIGN REQUIREMENT FOR MONOPOLE TOWERS

Transmission line hardware fittings, monopoles, towers and insulators shall be designedto accommodate bare hands the live line maintenance requirements. Established liveline maintenance consultants / experts shall be engaged by the Contractor in designingthe monopoles, towers, insulators and conductor fittings. The contractor shall ensurethat the live line maintenance must be workable.

Details of the insulators and conductors fittings are as the following:








a) Yoke Plates

Conductor yoke plates shall have notches for locating a double strain poleyoke used to remove the insulator string. The notches shall be in line with the

insulator string so that the yoke plate does not rotate when the load in the insulatorstring is taken up by the strain poles. The yoke plate shall be designed so that thedouble strain yoke can be installed without contacting the conductor clampsconsidering rotation of the clamps due to the minimum to maximum applied lineangle. The notches shall be oriented so that the strain poles can be attached besidethe insulator string to allow the insulator string to be lowered without conflict.

Conductor yoke plates designed to connect parallel insulator strings shall alsohave holes and a bearing surface designed to locate a single strain pole yoke used toremove the insulator strings. The holes and bearing surface shall be designed so thatthe single strain pole yoke can be attached without contacting any hardware attachedto the conductor yoke plate.

Yoke plates designed to connect parallel insulator strings to the tower or tothe conductors yoke plate shall have notches, holes and bearing surfaces forconnecting double and single strain pole yoke plates used to remove the insulatorstring. These yoke plates shall be designed such that the strain pole yoke plates canbe located without contacting any hardware attached to the yoke plate.

b) Hot Line Extension Links

On strain insulator assemblies, Hot Line Extension Links shall be used toconnect each end of the insulator strings to the yoke plates.

On suspension insulator assemblies, Hot Line Extension Links shall be usedto connect the non-energized end of the insulator string to the yoke plate orthe tower.

In addition, a Y-Clevis / ball or a socket / Y-Clevis fitting shall be installedbetween the insulators and the Hot Line Extension Links to allow articulationduring insulator removal. Hot Line Maintenance Links shall be designed toallow connection of a double strain pole yoke plate.

5.0 CONDUCTOR FITTINGS AND ACCESSORIES

The types of conductor fittings to be provided under the Contract shall be as follows :

a) Conductor mid-span and compression tension joints.

b) Sub-conductor spacers.

c) Vibration dampers.








d) Aircraft warning spheres, where required.

e) Conductor repair sleeves (for specific approved cases only).

f) Counter-weights, as required by design.

g) Armour Rods, as required by design .

5.1 EARTHWIRE SETS

Three types of earthwire sets suitable for earthwire conductors shall be provided. Allshackles shall be of the bow type. The following definitions are given for thedescriptions used in Schedule H of Volume 3 and elsewhere in the Specification :

a) Normal Earthwire Suspension Set

Comprising one suspension clamp, one shackle for attachment to the towerand suitable intermediate fitting and flexible earth bond of equivalentcross-sectional area as the earthwire to connect the earthwire to the tower.Two (2) earthing clamps shall be used to connect the flexible earth bond tothe tower and earthwire respectively.

b) Earthwire Tension Set

Comprising two dead-end clamps, two bolted jumper terminals, two shacklesfor attachment to the tower, one earthing clamp for attachment to the tower.

The parallel-groove earthing clamps shall be used for both suspensionand tension sets and shall be affixed to the tower with 12mm diameter

bolt/bolts.

5.2 ARMOUR RODS

Armour rods shall be of the preformed helical type manufactured fromaluminium-clad steel or aluminium alloy strands. Rods shall have a left hand directionof lay and shall fit tightly onto the conductor.

5.3 DEAD-ENDS

Dead-ends shall be of the compression type and shall be complete with jumper lug and jumper terminal and applied with grease. Jumper terminals shall be of the compressiontype and shall be connected to the dead end clamp by bolts. The compression clamp of

jumper terminals shall be angled at 60° to the dead-end clamp when assembled. Theelectrical conductivity and current carrying capacity of the complete assembly shall notbe less than that of an equivalent length of conductor. Other requirements forcompression type fittings are given in ACSR CONDUCTOR COMPRESSIONFITTINGS below. The cost for the dead-end clamps and jumper terminals shall bedeemed included in the Rates for Tension Insulator Sets and Earthwire Tension Sets .








5.4 MID-SPAN JOINTS

Mid-span joints shall be of the compression type and applied with grease. The electricalconductivity and current carrying capacity of mid-span joints shall not be less than an

equivalent length of conductor. Other requirements for compression type fittings aregiven in ACSR CONDUCTOR COMPRESSION FITTINGS below. The limitations onthe use of mid-span joints are given in LINE CONSTRUCTION (ACCESS, CLEARING,SURVEY AND ERECTION) of the Specifications. The cost for mid-span joints shall bedeemed included in the Rates for Erection of Conductor and Earthwire.

5.5 REPAIR SLEEVES

Repair sleeves shall be of the compression type and shall be designed to meet the testrequirements of BS3288 : Part 1 (1997). The use of repair sleeve shall be very minimalor not used altogether.

5.6 ACSR CONDUCTOR COMPRESSION FITTINGS

Compression fittings shall include the following :

a) Tension type - including dead-end clamps and mid-span joints.

b) Non-tension type - including jumper terminals and repair sleeves.

For each type of conductor, the design of the compression fittings shall be such thatonly one pair of dye is required to be used, i.e. one for steel sleeves and one foraluminium sleeves.

Tension type fittings shall not permit slipping, or cause damage to, or failure of the

complete conductor at a load less than 95% of the ultimate strength of the conductor. Allaluminium used in joints and clamps shall be of a purity of not less than 99.5%.

5.7 SPACER DAMPERS AND RIGID SPACER

This Specification covers the detail requirements for the design, manufacturing,test and shipping of corona free spacer-dampers for use on a three bundled Zebraand duplex ACIR conductor system, for maintaining the 400mm spacing and200mm spacing (at jumper loop) configuration of the subconductors, andcontrolling aeolian vibration and wind-induced subconductor oscillation.

5.7.1 Design Data

Climatological data observed in the vicinity of the transmission line route, plan andprofile drawings, conductor sag and tension data and a table of anticipated spanlengths are to be included in the drawings.

This information is intended to be used as a guide to the contractor for determiningthe required spacer-damper designs and spacing. The design of spacer-dampersfor the entire transmission line route shall be based on the worst case maximumwind velocity and a threshold wind velocity of up to 40 km/hr.








5.7.2 Detail Requirements For Spacer-Dampers

The spacer-damper shall be designed so that during operation, the conductor is notdamaged by its movements.

The spacer-damper shall be capable of being installed and easily removed withoutcompletely separating components. In addition, the clamp shall be capable of beingremoved and reinstalled on the conductor at the design torque.

Where elastomers or other non-metallic materials are used, they shall be capable ofwithstanding conductor temperatures of up to 90 degrees Celsius or 210 °C for ACIRconductors without permanent loss of essential properties. The energy absorbingassembly shall be designed to provide effective damping throughout a temperaturerange of 0 degrees Celsius to 75 degrees Celsius or 0°C to 240°C for ACIR conductors.

The elastomer or other energy absorbing assembly shall have adequate resistance tothe effects of ozone, ultra violet radiation and other atmospheric contamination over theentire temperature range.

Clamp bolts shall be steel with steel nuts and washer and shall be furnished with alocking system acceptable to TNB. The clamp shall be designed to permit ease ofinstallation and removal. The Contractor shall recommend the proper torque to beapplied to the bolts of damper clamps such that no slipping of the clamp and damageto the conductors will occur.

The energy absorbing assembly shall be electrically conductive. The Contractor shallspecify the measured resistance between clamps.

The spacer-damper shall maintain the proper subconductor spacing in the span undereveryday conditions and prevent contact between subconductors during conditions ofwind up to 30 meters per second.

The spacer-damper must also control wind-induced subconductor oscillation andaeolian vibration to the extent that damaged to the spacer-damper, conductor orinsulator and hardware assemblies will be prevented. The bending strain along thespans shall not exceed 200 microstrain peak to peak for aeolian vibration control andshall not exceed 600 microstrain peak to peak for subspan oscillation control.

Spacing of spacer-dampers shall be staggered to provide optimum control of wake-induced subspan oscillation.

The Contractor shall specify the location of spacer-dampers within the various spanlengths and the limit of the longest subspan that will enable the system to meet therequirements of this Specification. This data shall be for suspension to suspension,suspension to dead-end and dead-end to dead-end spans. All spacing data shall befurnished to TNB for approval. The Contractor shall furnish all necessary information toshow that its recommendation regarding type, the number and the position, of spacer-dampers is based on solid experimental and analytical data.








Spacer-dampers shall be used to maintain the 400mm spacing configuration of jumperloops.

Any special tools required for the installation and dismantling of the spacer-damper shallbe provided for each transmission line. The cost shall deemed included in the Contract

Price.

5.7.3 Rigid Spacers

Rigid spacers may only be used, where necessary, in jumper loop, and the cost shallbe deemed inclusive in the Contract price.

The dimensions and subconductor spacing shall be in accordance with the drawings.

The rigid spacers used to maintain the configuration of jumper loops shall be capable ofbeing installed and easily removed without completely separating components. Inaddition, the clamp shall be capable of being removed and reinstalled on the conductorsat the designed torque. Rigid spacer bolted clamps shall be furnished with a lockingsystem acceptable to TNB.

5.7.4 Marking

Each spacer-damper and rigid spacer shall be permanently marked by casting ordie-stamping with distinguishing numbers and/or letters corresponding to thoseused on the approved drawings identifying the manufacturer, type and nominalcross-sectional area or diameter of the conductor for which it is suitable and theupper side of spacer-dampers and rigid spacers.

5.7.5 Packing

Spacer dampers and rigid spacers shall be packed in sturdy wooden casessuitable for both ocean and inland transportation and shall be clearly marked withthe following information.

(a) Description of items(b) Number of pieces(c) Nett weight and gross weight(d) Contract number(e) Project name(f) Destination

5.8 ALLOCATION OF SPACER DAMPERS

The positions for fitting of spacer dampers shall be in accordance with themanufacturer's recommendations, based upon his test and performance experiencesaving always that the Engineer may instruct that the fitting of such spacers shall be inaccordance with his own experience and practice.








As for manufacturers’s reference and guidance, it is noted that for Duplex conductorsthe Employer had adopted the practice of using a maximum spacing of 60 metresbetween flexible line spacers. Rigid jumper spacers fitted in jumper loops are such thatthere must be no more than 4.5 metres of free sub-conductor in the loop, provided thatthere shall be a minimum of two spacers in any one jumper loop.

5.9 COUNTER-WEIGHTS

Counter-weights shall be provided as follows :

a) For attachment to jumper suspension insulator sets.

b) Where specifically required, for attachment to conductor in jumper loops.

Weights shall be of cast iron and made in two parts for bolting together over the twin

phase-conductors. The parallel grooves in the weights shall be of a suitable size for theconductors and shall be spaced at 200mm centres. All surfaces of the weights shall besmooth to prevent damage to the conductor and to minimise the effects of concentratedelectrical stress. The cost of counter weights for jumper suspension insulators and jumper loops shall be included in the rates for the supply and erection of completetowers.

5.10 JOINT COMPRESSORS

Where required by the Employer, motorised joint compressors, under the Contract,shall comprise of the following:

a) A self-contained petrol-driven motor and hydraulic pump unit.

b) 25 metres of hydraulic hose.

c) A 50-ton press head suitable for use in working aloft.

d) Sets of dyes suitable for all the conductors and earthwires mid-span joints,

dead-ends, jumper terminals and repair sleeves used in the project.

Full details of the compressors shall be submitted to the Engineer for approval. Outline

details shall be submitted with the Tender. Each joint compressor supplied shall becomplete with an Operating and Maintenance (O&M) Manual.

5.11 ALUMINIUM-COPPER CONNECTORS

Aluminium to copper connectors, if required, shall be of approved types and sodesigned as to prevent electrolytic action between the dissimilar metals. The actualaluminium-copper section shall be preformed by compression at the manufacturer's








works. In no case may copper conductor be allowed to lead away in a vertical planeabove aluminium components.

5.12 EARTHWIRES

At substations, earthwires shall be terminated either at the substation gantry or onsubstation earthwire masts as decided by the Engineer. Suitable terminal clamp fittingsshall be provided under the Contract. Earthwires are to be made electrically continuousat tension towers by jumpers or other approved means.

At suspension towers, the earth conductor shall be securely bonded to the towersteelwork with a conductor having a cross-sectional area of not less than the equivalentaluminium area of the earth conductor. The bond shall be flexible so as not to interferewith earthwire movement. At tension towers, the earth conductor shall be securelybonded to the tower steelwork in an approved manner.

5.13 AIR NAVIGATION OBSTRUCTION MARKING AND LIGHTING

Where required by the Employer, the Contractor shall supply and install or applyequipment/materials for marking and/or lighting of towers and overhead conductors asdescribed in the following Clauses and shall be complete with an Operation andMaintenance (O&M) manual. The Contractor shall provide all required details, i.e. towerdetails, tower height from Mean Sea Level, airport runways, etc. to the Department ofCivil Aviation (DCA), Malaysia, and related local authorities for approval.

All marking and lighting shall be accordance to Airport Standard Directive by DCA

5.13.1 Marking of Towers

Towers shall be painted for the purpose of marking air navigation obstruction. TheContractor shall supply and apply all cleaning and painting materials on these towersaccording to the following requirements :

a) Surface Preparation

The surface of the tower shall be primed for painting using SSPC-SPI (US PaintStandard) Solvent Cleaning.

b) Paints

The standard colours of the paint required for the works shall be as described

below, or as approved by the DCA, Malaysia.

ColourMunsell’s Number

Orange (Yellowish – red) 2.5 YR 6/13Orange n-9.5








All paint material used must be VOC compliance i.e., volatile content in theproduct must not be more than 5% by weight. Approval from the S.O. must beobtained before commencing of work.

c) Painting

All painting operations shall be performed after the steel towers have beencompletely erected and the air navigation obstruction lighting installed. All oil,grease and dirt shall be removed using solvent cleaning method before coatingis applied. No painting shall be done in cold, damp, foggy or dusty atmospheres.Care must be taken or work totally halt if rain is expected within 2 hours beforeor after painting.

One coat of water-based, lead free with rust inhibitor pigmented hybrid acryliccoating and followed by another coat of water-based, lead free with rust inhibitorpigmented hybrid acrylic finish coating to be applied to all exposed surfaces ofthe steel towers. The colours of finish coats shall be applied alternatively orangeand white in equal vertical sections having dimensions of approximately 1/7 ofthe longest dimension, thus permitting both the top and bottom sections to beorange in colour. Section lines between colours shall be sharply defined.

The thickness of each coat shall not be less than the following values :

CoatingSystem

ProductDescription

Dry Film Thickness(micron)

Special Notes

First Coat

Water-based, leadfree with rust inhibitive

pigmented hybridacrylic coating

60-75

Application by

brush or shortnap roller.

Final Coat

Water-based, leadfree with rust inhibitive

pigmented hybridacrylic coating

60-75Application bybrush or shortnap roller.

The recoating time for in-between coats is 4 hours minimum. Prior tocommencement of the painting work, the Contractor shall submit a workprogram including the quantity of paint and dimension of painting sections forTNB’s approval.

d). Quality Control

To ensure material and workmanship quality are consistent throughoutthe project, contractor must perform the following test to ensure all expect ofthe work are carried out in strict accordance to manufacturer’s instruction.








Item TestFrequency

1. Wet/dry film thickness Daily

2. Cross cut adhesion Random

3. Pull out adhesion Completion of each tower

Test and report witnessed by the contractor and owner’s representative must besubmitted for S.O.’s approval every week.

5.13.2 Warning Spheres Of Overhead Conductors

Where required by the Employer or due to the requirements of the DCA, Malaysia,aircraft warning spheres shall be fitted to the earthwires of the transmission lines. Thewarning spheres shall be of minimum 600mm in diameter and manufactured offibreglass. The sphere shall be of orange (to standard international regulations) incolour and not fade when exposed to direct rays of the sun. Provision for drainage shallbe provided.

Suitable clamping devices shall be provided which will not damage the conductor butwill prevent the sphere from twisting or slipping on the conductor. All metal parts used

for holding the spheres in position shall be of galvanised mild steel.

The spheres shall be fitted to both the earthwires on the line. The position of thespheres shall meet the following requirements :

a) The spheres on the two earthwires for any span shall be so staggered that themaximum distance between any two spheres on each earthwire is not greaterthan 60 metres.

b) The first and the last spheres in any span shall be approximately 15 metre fromthe towers defining span.

5.13.3 Aircraft Warning Light

Where required by the Employer, towers shall be fitted with obstacle lights as definedby the latest edition of “ICAO Annex 14 – Aerodomes,Volume I, Chapter 6 – Visual Aidsfor Denoting Obstacles” and ASD 404 . The characteristic of obstacle lights shall be inaccordance to ASD 404 and to comply with the relevant British standards or otherapproved alternative Standards. These obstacle lights shall be fitted as per accordanceto ASD 404 and to be operated by batteries charged by solar cells.








The lighting system shall be in accordance to ASD 404 and approved by DCA

Storage batteries for the solar cells system shall be sized according to daily loadvariations. Tenderers are required to submit calculations on power consumption and

derivation of the proposed battery capacity, and the number of solar cells required.

Storage batteries for the solar cell system shall be supplied together with the chargecontroller, terminal connectors and enclosed in a battery box that can be secured.

Operation of the lighting system proposed to be used on the steel towers shall be to theapproval of the Engineer. Any metal portions of the tower shall be galvanised or madeof non-corrosive material. All obstacle lights, solar cells, batteries and other associatedequipment shall be provided by the Contractor and paid at the scheduled rates.

6.0 INSPECTION AND TESTING

6.1 TESTS AT MANUFACTURER’S WORK

6.1.1 Summary Of Tests At Works

The following tests shall be carried out, where required, at the Manufacturer's Works(unless otherwise approved) :-

a) Insulators and EarthwireFittings including SuspensionClamps

- Type, sample and routine tests

b) Conductor Fittings - Type, sample and routine tests

6.1.2 Insulator and Earthwire Fittings including Suspension Clamps

The type tests, sample and routine test shall be caried out in accordance with BS3288 : Part 1 (1997).

a) Type Test

List of Type Test to be carried out are:

1) Verification of dimensions2) Mechanical test3) Galvanising test

b) Sample Test

List of Sample Test to be carried out are:

1) Verification of dimensions2) Mechanical test








3) Galvanising test

c) Routine TestList of Routine Test to be carried out are:

1) Mechanical Test ( for casting & welded parts)

6.1.3 Conductor Fittings

The type tests, sample and routine test shall be caried out in accordance with BS3288 : Part 1 (1997).

a) Type test

Dead-ends & Mid-span jointsList of Type Test to be carried out are:

1) Mechanical type tests2) Electrical type tests ( Resistance and Heat Cycle test)

Repair SleeveList of Type Test to be carried out are:

1) Mechanical type tests2) Electrical type tests

b) Sample and Routine Tests

Sample and routine test shall be carried out in accordance with BS 3288 : Part 1(1997).

6.1.4 Spacers, Vibration Dampers and Spacer Dampers.

6.1.4.1 Flexible Spacers

The type tests, sample and routine test shall be caried out in accordance with IEC61854.

a) Type TestList of Type Test to be carried out are:

1) Visual examination2) Verification of dimension

3) Corrosion protection (galvanizing) test : BS EN ISO 1461 (1999)4) Corona and Radio Interference Voltage (RIV) Test5) Clamp slip Test6) Longitudinal Slip Test7) Transverse (Torsional) Slip Test8) Mechanical Strength (Short Circuit) Test9) Elastomer Properties Test10) Flexibility test11) Breakaway bolt test








12) Clamp bolt tightening test

b) Sample Test


1) Visual examination2) Verification of dimensions3) Mechanical test4) Corrosion Protective (Galvanizing) test5) Electrical resistance test

c) Routine Test

Tests to be carried out are as follows:

1) Visual examinations2) Verification of dimensions3) Test reporting requirements4) Certificate of compliance

6.1.4.2 Rigid Spacers

The type tests, sample and routine test shall be caried out in accordance with IEC61854.

a) Type Test

List of Type Test to be carried out are:(1) Visual examination(2) Verification of dimensions(3) Corrosion protection (galvanizing) tests : BS EN ISO 1461(1999)(4) Corona and Radio Interference Voltage (RIV) Test(5) Clamp slip Test(6) Longitudinal Slip Test(7) Transverse (Torsional) Slip Test(8) Mechanical Strength (Short Circuit) Test(9) Breakaway bolt test(10) Clamp bolt tightening test

b) Sample Test


1) Visual examination2) Verification of dimensions3) Mechanical test4) Corrosion Protective (Galvanising) test5) Electrical resistance test








c) Routine Test


1) Visual examinations

2) Verification of dimensions3) Test reporting requirements4) Certificate of compliance

6.1.4.3 Vibration Dampers

The tests shall be in accordance with BS3288: Part 1 (1997)

a) Type TestList of Type Test to be carried out are:

1) Visual examination2) Verification of dimensions

3) Corrosion protection (galvanizing) test4) Longitudinal slip test5) Mechanical type test of messenger wire fastening6) Torsional Slip Test7) Clamp Bolt Tightening Test

b) Sample Test


1) Verification of dimensions2) Mechanical test

3) Galvanising test

6.1.4.4 Spacer-Dampers

The Contractor shall subject the spacer-dampers offered in accordance with thisspecification to type, sample and routine tests to verify that the spacer-dampers willperform acceptably during service. The tests shall be in accordance with IEC61854:1998 Section 6 and 7. All testing costs shall be borne by the Contractor andshall be included in the cost of the spacer-dampers.

a) Type Test

Type tests are mandatory for each different type of spacer-damper supplied to thisspecification. All type tests shall be carried out in accordance with IEC 61854

List of Type Test to be carried out are:

1) Visual examination2) Verification of dimension3) Corrosion protection (galvanizing) test : BS EN ISO 1461 (1999)4) Corona and Radio Interference Voltage (RIV) Test5) Clamp slip Test








6) Longitudinal Slip Test7) Transverse (Torsional) Slip Test8) Mechanical Strength (Short Circuit) Test9) Elastomer Properties Test10) Fatigue test

11) Flexibility test12) Breakaway bolt test13) Clamp bolt tightening test14) Verification of vibration behaviour of bundle conductor/ spacer system

• Aeolian vibration : IEC 61897 (1998)

• Suspan oscillation

b) Sample Test

Sample tests are intended to verify the quality of materials and workmanship. Sampletest are mandatory for each order of spacer-dampers supplied to this specification. All

sample tests shall be carried out in accordance with IEC 61854List of Sample tests to be carried out are:

1) Visual examination2) Verification of dimension3) Corrosion protection (galvanizing) test : BS EN ISO 1461 (1999)4) Breakaway bolt test5) Clamp bolt tightening test6) Simulated short-circuit current and compression-tension test7) Electrical resistance test8) Characterisation of the elastic and damping properties9) Flexibility test

c) Routine Test

All routine tests shall be carried out in accordance with IEC 61854.


1) Visual examinations2) Verification of dimensions3) Test reporting requirements4) Certificate of compliance

7.0 TEST DURING ERECTION

7.1 Conductor And Earthwire Joint Tests

The resistances of all completed clamps, joints and terminal fittings shall be accuratelymeasured by Contractor in the presence of Employer. Where the joint consists ofseveral parts bolted together (e.g. dead end clamp with bolted-on jumper terminal) theresistance to be measured is that of the complete assembly. The resistance of any suchfittings shall not exceed 75% of the resistance of an equivalent length of conductor,measured adjacent to the fitting, and the current carrying capacity shall be at least






DOC NO TTS LN FTNES R i i N 0 D t 1 J 2011 P 21 f 21

100% of that of the conductor. In addition, the centralisation of the steel inner sleeves of joints shall be checked by the Employer before erection.

The Contractor shall provide suitable equipment for making the above tests, and shallsubmit details of the proposed instruments to the Employer for approval. Suitable

clamps should also be supplied for connecting the current leads of the measuringinstrument to the test sample to provide adequate surface contact at the interfaces. Testprobes as used for potential contacts are unsuitable for current connections. Stringing ofconductor and earthwire shall not commence until the instruments are on Site andready for use.

2. Fittings & Accessories for Overhead Line

Documents

Transcript of 2. Fittings & Accessories for Overhead Line