17. TECHNICAL SPECIFICATION OF 22KV XLPE CABLE

1. SCOPE:The spec i f i ca t ion covers des ign , manufac ture , shop tes t ing , pack ing and de l i veryof 22 kV, mult i core, cross l inked polyethylene insulated power cables sui tablefor the 3 phase AC-50 Hz system with the nominal vol tage of 22 kV which mayreach maximum of 24kV. These cables shal l pr imari ly be designed for ef fect ivelyear thed neut ra l sys tem. The cab le sha l l be manufac tured s t r i c t l y con forming totEC 60502-1 .

2 . SERVICE CONDITIONS:lV la te r ia l to be supp l ied aga ins t th is spec i f i ca t ion sha l l be su i tab le fo r sa t is fac to rycont inuous opera t ion under the fo l low ing t rop ica l cond i t ions .

Maximum average ambient temperatureM inirnurn average ambient temperatureRelat ive f lurnidi ty MinimumRelative Humid ity MaximumMaximum Annual RainfallMaximum Wind PressureAltitude above MSL

3 r2250%.84%.2592 mm74.5 kglcm12m

lsoceraniclevel / l 6 0 d a

3. STANDARDS:3.1 Unless otherwise specif ied elsewhere in this specif icat ion, the rat ing as wel l as

per fo rmance and tes t ing o f the HT XLPE power cab les sha l l con form to the la tes trev is ions ava i lab le a t the t ime o f p lacement o f o rder o f a l l the re levant s tandardsas l i s ted be l low, bu t no t l im i ted to the sa id l i s t . A l l cab les made w i th XLPEinsu la t ion sha l l be tes ted and/or cer t i f ied to meet the per fo rmance parametersas per Annexure- | a t tached.

IEC 60183 - Guide to the select ion of high vol tage cableslEC60228 - Conductors o f insu la ted cab les . Gu ide to the d imens iona l l im i ts

o f c i rcu la r conductors .IEC 60332 - 3 Tes ts on e lec t r i c cab les under f i re cond i t ions . Tes ts on

bunched w i res or cab les .IEC 60502-2 Extruded sol id dielectr ic insulated power cables for rated vol tages

from 1kV to 30 kV.IEC 60811 Pts 1 -5

Common tes t methods fo r insu la t ing and sheath ing mater ia ls o fe lec t r i c cab les .

IEC B85 Pts 1 - 3 E lec t r i c tes t methods fo r e lec t r i c cab les .

9. Moderately hot and humid climate conducive to growth of fungus and rust.

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tEc 28 In ternat ional Standard of Resis tance for Copper conductor

4. GENERAL TECHNICAL REQUIREMENTS:4.1. 12.7/22 kVearthed, mult i core power cables shal l normal ly be with stranded

compacted H2/H4 grade a luminum conductor , p rov ided w i th conductorscreen ing (o f ex t ruded semi -conduct ing c ross l ink mater ia l ) and sha l l beinsu la ted w i th water t ree re ta rdant (TR) XLPE o f na tura l co lour . The insu la t ionscreen ing sha l l be prov ided cons is t ing o f ex t ruded semi -conduct ing c ross l inkmater ia l in combina t ion w i th a meta l l i c layer o f copper tapes . Three suchscreened cores sha l l be la id up together w i th f i l l e rs and/or b inder tapes wherenecessary and prov ided w i th ex t ruded inner sheath ing o f heat res is tan t PVCMax imum cont inuous opera t ing tempera ture sha l l be 90sC under normalopera t ion and 250sC under shor t c i rcu i t cond i t ion

4 .2 CABLE DESIGN & CONSTRUCTION:4 .2 ,1 Conductor :

E lec t ro ly t i c g rade a luminum conductor sha l l be o f H2/H4 grade. The shape o fconductor sha l l be compacted , s t randed, and c i rcu la r .

4.2.2 Conductor screen/Sh ie ld :The conductor sc reen sha l l be an ex t ruded layer o f b lack , semi -conduct ingcompound. The a l lowab le opera t ing tempera tures o f the conductor sh ie ld sha l lbe equa l to o r g rea ter than those o f the insu la t ion . The conductor sc reen sha l l beex t ruded in the same opera t ion as the insu la t ion . The semi -conduct ing screensshould be effect ively cross l inked to achieve 90sC cable rat ing. The interfacebetween the ex t ruded conductor sc reen and insu la t ion sha l l be f ree o f any vo ids .The volume resist iv i ty of the screen mater ial shal l not exceed 1000 Wm at 90'C.

4 .2 .3 Insu la t ion :The insu la t ing mater ia l sha l l be Cross L inked Po lye thy lene (XLPE)cured bydrycur ing process and app l ied by ex t rus ion process The insu la t ion sha l l be anextrusion of dry cured thermosett ing cross l inked poly ethylene water treere tardant mater ia l ra ted fo r 90qC cont inuous ooera t ion .The insu la t ing mater ia l sha l l have exce l len t e lec t r i ca l p roper t ies w i th regard tores is t i v i t y , d ie lec t r i c cons tan t and loss fac to r and sha l l have h igh tens i le s t rengthand res is tance to abras ion . Th is sha l l no t de ter io ra te a t e leva ted tempera turesor when immersed in water . The insu la t ion sha l l be pre ferab ly f i re res is tan t andres is tan t to chemica ls l i ke ac ids , a lka l i s , o i l s and ozone.The insu la t ion proper t ies sha l l be s tab le under thermal cond i t ions ar is ing ou t o fcont inuous opera t ion a t conductor tempera ture o f 90sC r is ing momentar i l y to250sC under shor t c i rcu i t cond i t ions . l t sha l l be f ree f rom any fo re ign mater ia l o rporos i ty v is ib le to the una ided eye. The insu la t ion sha l l be so app l ied tha t i t f i t sc lose ly on the conductor and i t sha l l be poss ib le to remove i t w i thout damagingthe conductor.The extruded water tree retardant (TR) XLPE insulat ion shal l be of very highdegree of pur i ty. The manufacturer should provide the cert i f icat ion that theTRXLPE compound used has proven t rack record . The t ree re ta rdant c ross l inked

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po lye thy lene insu la t ion shou ld be such as to re ta rd the deve lopment and growthof water t rees in the compound. The insu la t ion compound sha l l be c lean w i thlow leve ls o f con taminat ion . The qua l i t y o f insu la t ion shou ld be good andinsu la t ion shou ld no t be de ter io ra ted when exposed to the c l imat ic cond i t ions .The average th ickness o f insu la t ion sha l l no t be less than the nomina l va lue asspec i f ied . No to le rance on the negat ive s ide sha l l be acceptab le .

4 .2 .4 Insu la t ion Screen/ Sh ie ld :Ex t ruded Semi -conduct ing screen ing and meta l l i c sc reen ing o f copper tape sha l lbe genera l l y as per IEC 60502-1The semiconduct ing compound sha l l be su i tab lefo r the opera t ing tempera ture o f the cab le and compat ib le w i th the insu la t ingmater ia l .The insu la t ion screen sha l l be an ex t ruded layer o f b lack semi -conduct ing compound and cont inuous ly covers the who le a rea o f the insu la t ion .The semiconduct ing screens should be effect ively cross l inked to achieve 90sCcab le ra t ing . The contac t sur face be tween insu la t ion and insu la t ion screen sha l lbe smooth and free from protrusion and irregular i t ies. The interface betweenthe insu la t ion and insu la t ion screen sha l l be f ree o f anv vo ids . Insu la t ion screens h a l l b e s t r i p p a b l e t y p e .T h e m e t a l l i c s c r e e n s h a l l c o n s i s t o f a l a y e r o f c o p p e r t a p e a p p l i e d i n h e l i c a l f o r m

4.2 .5 Core ldent i f i ca t ion :Ind iv idua l core o f mu l t i -core cab les sha l l be co lour coded and/or numbered fo rproper ident i f i ca t ion , in accordance w i th the re levant spec i f i ca t ion .

4 .2 .6 Lay ing up o f cores :In th ree core cab les , the cores sha l l be la id together w i th a su i tab le r igh t handlay . The in te rs t i ces sha l l be f i l l ed w i th non-hygroscop ic mater ia l . Fur ther , thecompounds used w i th f i l l e rs sha l l be such as to have no de le te r ious e f fec t onother components o f the cab le and to be s tab le a t cab le tempera tures .

4.2.7 lnner Sheath:The la id up cores sha l l be prov ided w i th inner sheath app l ied by ex t rus ionprocess . l t sha l l be ensured tha t the shape is as c i rcu la r as poss ib le . l t sha l l beapp l ied to f i t c lose ly on to the la id up cores and sha l l be poss ib le to removeeas i l y w i thout caus ing any damage to the under ly ing insu la ted cores andscreens . The th ickness o f the inner sheath sha l l be s t r i c t l y as per spec i f i ca t ion ,No to le rance on the negat ive s ide sha l l be acceptab le ,

4 .2 .8 Armor ing :The armour ing sha l l be o f ga lvan ized round s tee lw i res fo r mu l t i core cab les . Thearmour ing sha l l be app l ied as c lose ly as prac t ica l . The ga lvan ized s tee l w i ressha l l comply w i th the requ i rements o f lS : 3975-1988 w i th la tes t amendments . )The d imens ions o f the ga lvan ized s tee l w i re sha l l be as per re levantspec i f i ca t ions ment ioned ear l ie r in th is document . No to le rance on the negat ives ide sha l l be acceptab le .

4 .2 .9 Outer Jacket :The outer jacket shal l consist of extruded tough outer sheath of PVC compoundinsu la t ion over the armour ing . Inner conductor sh ie ld ing , TR XLPE insu la t ion andouter sh ie ld ing sha l l be ex t ruded in one opera t ion by spec ia l p rocess to ensure

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tha t the insu la t ion is f ree f rom contaminat ions and vo ids and per fec t bond ing o finner & ou ter sh ie ld ing w i th insu la t ion is ach ieved.

4 .3 DISCHARGE FREE CONSTRUCTION:4 .3 .L The inner conductor sh ie ld , TR-XLPE insu la t ion , and ou ter insu la t ion sh ie ld sha l l

be ex t ruded w i th a t rue t r ip le ex t ruder head us ing a d ry cure process . Theconductor sc reen, Insu la t ion and lnsu la t ion screen sha l l a l l be ex t ruded in s ing lepo in t a t one t ime process to ensure homogene i ty and reduc t ion o f vo ids , in theinsu la t ion and the screen ing sys tem o f the cab le . The b idders a re reques ted toe labora te the manufac tur ing techn ique adopted by the i r manufac turers toach ieve th is mot ive .The Company w i l l o rder the ver i f i ca t ion o f t rue t r ip le ex t rus ion dry cure processat manufac turer ' s works as a p re qua l i f i ca t ion i f i t i s techn ica l l y accept ing theb id . Dur ing ver i f i ca t ion i f i t i s found tha t the f i rm is no t manufac tur ing the cab lewith true tr ip le extrusion dry cure process the offer shal l be rejected.

4 .4 CONTINUOUS A.C. CURRENT CAPACITY:Cont inuous a .c . cur ren t capac i ty sha l l be as per Tab le g iven be low.Cont inuous A.C. cur ren t capac i ty in Amps. a t max imum conductortemp. o f 90sC.

When la id d i rec t in the ground 30eC When laid in air_40eCConductors izes in sq.m m .

11 kV 22/33 kv 11./22/33 Kv

70 sq.mm95 sq mmL20 sq mm150 sq mm1-85 sq mm240 sq mm300 sq mm400 sq mm500 sq mm

160190215240270315355405450

155t7519522525529032538s450

1652002302653 1 0345396460590

4.5 SHORT CIRCUIT CURRENT:Shor t c i rcu i t cur ren t o f 1 .1 , ,22 & 33kV XLPE cab le sha l l be as per Tab le g ivenbe low.

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Durat ion of ShcrtCircui t in sec

Area of Al . Conductor Short c ircui t current in kA

7 0 s q . m m9 5 s q . m m

1-20 sq .mm150 sq .mm1 8 5 s q . m m .240 sq .mm.3 0 0 s q . m m .4 0 0 s q . m m .5 0 0 s q . m m630 sq .mm

6 . 5 88.93

LL.281,4.I017.3922.5628.2037.6047.0059.20

5. TESTS AND TESTING FACILITIES :5 .1 TYPE TESTS:

A l l the type tes ts in accordance w i th l s : 7098 (par t 2 ) - 1985, amended up todate, shal l have been performed on cable samples. Test cert i f icate copiesofda te no t ear l ie r than 5 years f rom the da te o f th is supp ly sha l l be fu rn ished fo racceptance of the lot .

ROUTINE TESTS:A l l the Rout ine tes ts sha l l be car r ied ou ton each and everyde l i very length o fcab le . The resu l t shou ld be g iven in tes t repor t . Par t ia ld ischarge tes t must becar r ied ou t in a fu l l y sc reened tes t ce l l . l t i s , there fore , abso lu te ly essent ia l tha tthe manufac turer shou ld have the appropr ia te type o f fac i l i t y to conduct th istes t wh ich is rou t ine tes t . The de ta i l s o f fac i l i t y ava i lab le in the manufac turer sworks in th is connect ion shou ld be g iven in the b id .

5.3 ACCEPTANCE TESTS:A l l Acceptance tes ts inc lud ing the op t iona l tes t as per c lause no l -8 .4 andF lammabi l i t y Tes t sha l l be car r ied ou t on sample taken f rom the de l i very lo t .

6 PACKING AND MARKING:6 .1 IDENTIFICATION MARKS ON CABLE:

The fo l low ing par t i cu la rs sha l l be proper ly leg ib le embossed on the cab le sheatha t the in te rva ls o f no t exceed ing one meter th rough ou t the length o f the cab le .The cab les w i th poor and i l leg ib le emboss ing sha l l be l iab le fo r re jec t ion .a) Vo l tage grade TR-XLPE Cab le .b ) Y e a r o f m a n u f a c t u r e .c ) S ize o f cab le

6 .2 The cab le sha l l be supp l ied in cont inuous s tandard length o f 250 runn ing meterswi th p lus minus 5% to le rance wound on non re tu rnab le wooden drum o f good

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6.31)2 )

qua l i t y and non-s tandard lengths no t less than 100 meters up to 5% o f theordered quant i t y sha l l be accepted . A l te rna te ly cab le can be supp l ied wound onnon- re tu rnab le s tee l d rum wi thout any ex t ra cos t to the purchaser .Supp l ie r shou ld p rov ide s ta t i s t i ca l da ta regard ing cab les o f a l l s izes v iz . -Weigh t o f one meter o f f in ished produc t o f cab le o f var ious s izes and ra t ings .Weigh t o f one meter o f bare conductor used fo r cab les o f var ious s izes andrat i ngs.

7. GUARANTEE:Supp l ie r sha l l s tand guarantee towards des ign , mater ia ls , workmansh ip &qua l i t y o f p rocess /manufac tur ing o f i tems under the cont rac t fo r due andin tended per fo rmance o f the same, as an in tegra ted produc t de l i vered underthis contract. In the event any defect is found by the purchaser up to a period of1-2 months from the date of commissioning or 1-8 months from the date ofins ta l la t ion , wh ichever i s ear l ie r , supp l ie r sha l l be l iab le to under take toreplace/rect i fy such defects at his own costs. within mutual ly agreed t imeframe,and to the en t i re sa t is fac t ion o f the purchaser , fa i l ing wh ich the purchaser w i l lbe at l iberty to get i t replaced/rect i f ied at suppl ier 's r isks and costs and recovera l l such expenses .

ANNEXURE - I

A l l cab les made w i th TR-XLPE Insu la t ion shou ld be tes ted and/or cer t i f ied tomeet the fo l low ing per fo rmance parameters .Min. Avg, Electr ical BreakdownStrength (Qual i f icat ion test) Kv/mm > 25lmpulse Strength Kv/mm > 83WaterTree Length mm 0.25Max. Bowt ie Tree Dens i ty (Number per 1 -6 .4 cu . cm) Max imum 15(0 .1 .2 -0 .25 mm range)Manufac tur ing processes to p roduce h igh-qua l i t y cab les w i th the fo l low ingcha racter ist ics:. Cure consistency with hot set/creep less than 1,00%. No vo ids la rger than 75 mic rons per 1 -6 .4 cub ic cm. No ambers la rger than 250 mic rons per 1 -6 .4 cub ic cm. No contaminants la rger than 1-25 mic rons and less than 5 be tween 50-125microns per cub ic 16 .4 cub ic cm tes ted .. Par t ia l d ischarge less than 5 p ico cou lombs a t 52 kV. Neut ra l indent on cab le i s less than 375 mic rons. Cable insulat ion concentr ic i ty greater than 90% tested. No pro t rus ions grea ter than 75 mic rons a t the conductor sh ie ld and 125microns a t the insu la t ion sh ie ld

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