3
STANDARD PROCEDURES FOR PREPARING
33KV CABLES
Single-Core Copper Wire Screened Polymeric Cables
3.1.1
Removing the Outer Sheath
•
leanandabradetheoutersheathwithanapprovedabrasivepaperfor150mmbeyond
C
thesheathremovalpoint.Marktheremovalpointoftheoutersheathasindicatedonthe
relevantjointinginstructionusingaChinagraphpencil.
•
orcableswithsemi-conductingoutersheaths,eithergraphiteoranextrudedlayer,extra
F
careshouldbetakentoensurethatalltracesofconductivematerialareremoved.
•
seanapprovedtooltoremovethesheath.checkthetoolcuttingwheelissettothe
U
correctdepthtoavoiddamagingthecopperwirescreensbelow.
•
tartingattheremovalpointmakeacircularcutaroundthecable.Cutalongthecableto
S
thepositionofthesheathremovalpoint,andremovethesheath.
U
N
C
O
N
TR
O
LL
ED
3.1
UK POWER NETWORKS 33KV JOINTING MANUAL I 2012
Section 3 I Page 1
emovethefabricorplastictapewrapfromthescreenwireusinganapprovedknife,
R
takingcarenottodamagethecopperwiresbelow.
•
nwindthecopperwiresandlaythembackalongtheoversheathinthepositionrequired
U
bythejointbeingmadeandsecurewithPVCtape.Ifpreparingforaterminationalength
ofredmasticsealingtapeshouldbeappliedtotheoutersheathfollowingtheappropriate
instruction.
3.1.2
Removing the Bonded Polymeric Screen
•
heapprovedbondedscreenstrippingtoolcanbeusedtoleavevariouslengthsofblack
T
insulationscreenfromtheoutersheathcut.Thismeasurementvariesdependinguponthe
typeofjoint:
•
Single-Corestraightjoints=40mm.
•
Single-Corebranchjoints=80mm.
•
Trifurcatingjoints=100mm.
•
Potends=80mm.
•
Single-Coreterminations=40mm.
U
N
C
O
N
TR
O
LL
ED
•
Section 3 I Page 2
UK POWER NETWORKS 33KV JOINTING MANUAL I 2012
mearathincoatingofSiliconegreaseovertheconductingscreenlayer.Startingatthe
S
openendofthecable,setthetooltothecorrectcuttingdepthsothattheentirescreen
isremovedwithonlytheminimumamountofinsulation.Itisessentialthatthecoreisas
straightaspossibleforthisoperationotherwisetracesofthescreenmaybeleftbehind.
•
ontinueturningthetooluntilitbuttsupagainstthestopposition(dependantonthe
C
screenterminationpoint)andcontinuetoturnthetooluntilasmoothrightangledtaperis
produced.Testthetoolfirstlyontheoverlapsectionofthecoreifrequired.
•
heinsulationnowrequirespolishingsmoothwithanappropriatealuminiumoxidegrit
T
paper(minimum150grade)untilsmoothandfreeofridges.Tofinishthisprocess,reverse
thepaperand'buffup'withthesmoothside.
U
N
C
O
N
TR
O
LL
ED
•
UK POWER NETWORKS 33KV JOINTING MANUAL I 2012
Section 3 I Page 3
Cleananddegreasetheinsulationwithanapprovedsolventwipetoremovealltracesof
anyremainingloosematerial.Alwayswipefromtheopencoreendtowardsthescreen
wirestoavoidcontaminatingtheinsulationwithcarbonfromtheremainingscreen.
3.1.3
Removing the Polymeric Insulation
•
UsetheapprovedAlroctoolandsetthe'stopgauge'totheconnectorinsertiondepth.
•
ositionthetoolattheopencoreendandadjustthebladetotherequireddepth;justdeep
P
enoughsothebladedoesnotdamagetheconductor.
•
otatethetoolalongthecoreusingthespiralcutsettinguntilthestopgaugepreventsit
R
frommovinganyfurther.
U
N
C
O
N
TR
O
LL
ED
•
Section3IPage4
UK POWER NETWORKS 33KV JOINTING MANUAL I 2012
emovethetoolandtheinsulationspiral.Carefullyremovetheremainingconductorscreen
R
usinganapprovedknife.
3.2
Single-Core Lead Covered Cables
3.2.1
Removing the Outer Serving or Sheath
•
arkthepositionoftheservingorsheathterminationasindicatedontherelevantjointing
M
instruction.
•
akeacircularcutatthismarkusinganappropriateapprovedtool.Checkthatthecutis
M
onlythreequartersthroughthesheaththickness.
U
N
C
O
N
TR
O
LL
ED
•
UK POWER NETWORKS 33KV JOINTING MANUAL I 2012
Section3IPage5
owmakealengthwisecutalongthesheathtowardsthesheathcutpositiontakingcare
N
nottodamagetheunderlyingleadsheath.
•
ifttheedgeofthesheathandunwrapalongitslength,tearingoffatthecircularcutpoint.
L
Theuseofagastorchmayassistthisoperationifnecessary.
3.2.2
Removing the Lead Sheath
•
leananddegreasetheleadsheathusingtheapprovedsolventwipes.Markthelead
C
sheathattheremovalpointasindicatedontherelevantjointinginstructionusinga
Chinagraphpencil.
U
N
C
O
N
TR
O
LL
ED
•
Section 3 I Page 6
UK POWER NETWORKS 33KV JOINTING MANUAL I 2012
seanapprovedhackknifetomakeanindentedcircularcutaroundtheleadsheath,
U
takingcaretoonlycutpartwaythroughthesheath.
•
uttheleadsheathacrossfromtheopencableendtothecircularcut.Useanappropriate
C
approvedhackknife.TakecarenottodamagetheCopperWoventapebelow.
•
pentheleadsheathupalongthelengthofthecutandcarefullyunwraptheleadsheath
O
againsttheringcut.
U
N
C
O
N
TR
O
LL
ED
•
UK POWER NETWORKS 33KV JOINTING MANUAL I 2012
Section 3 I Page 7
Removing the Copper Woven Tape (CWT)
•
nwindtheCWTandcarefullyremoveitbycuttingitagainsttheleadsheathedgewithan
U
approvedknifetoleaveasmoothfinish.
3.2.4
Removing the Insulation Screen
•
arkthescreenpaperswithaChinagraphpencilattheremovalpointindicatedinthe
M
relevantjointinginstruction.Tieatwinebinderaroundthescreenatthispoint.
•
nwrapthescreencarefullytotheterminationpointandremoveitbyneatlytearingagainst
U
thetwinebinder.Removeanycarbonpaperbelowthescreentothesametermination
position,followedbytwooftheinsulationpapers.
U
N
C
O
N
TR
O
LL
ED
3.2.3
Section3IPage8
UK POWER NETWORKS 33KV JOINTING MANUAL I 2012
Removing the Insulation Papers
•
nlyremovethepapersafterfittingthebarriertubingasdescribedinsection4.1.1.
O
Marktheinsulationpapersatthepointofremovalasindicatedintheappropriatejointing
instruction.Usinganapprovedsharpknife,cutaroundthecorethroughthepapersand
clearbarriertubetakingcarenottodamagetheconductorbelow.
•
Removetheclearbarriertubebypullingtowardstheendwithagentletwistingmovement.
•
Unwrapthepapersuptothecutpositionandtearoffneatlyagainstthebarriertubeedge.
•
Cleananysurpluscompoundfromthecableconductorwithanapprovedsolventwipe.
U
N
C
O
N
TR
O
LL
ED
3.2.5
UK POWER NETWORKS 33KV JOINTING MANUAL I 2012
Section 3 I Page 9
Three-Core Paper Insulated Cables
3.3.1
Removing the Outer Hessian Serving or (PE) Sheath
•
arkthepositionoftheservingorsheathterminationasindicatedontherelevantjointing
M
instruction.
•
Wearsuitablegloveswhileremovingtheserving.Placeawirebinderaroundtheservingat
theremovalpointandscoreinfrontofthebinderusinganapprovedknife.
•
emovetheservingwiththeapprovedknifeandheatfromagastorchifrequiredorinthe
R
caseofapolyethylenesheathusetheapprovedtoolforthisoperation.
N
C
O
N
TR
O
LL
ED
3.3
Removing the Steel Wire Armour
•
laceawirebinderaroundthearmourwiresatthepointofremovalasindicatedinthe
P
relevantjointinginstruction.
U
3.3.2
Section3IPage10
UK POWER NETWORKS 33KV JOINTING MANUAL I 2012
singanapprovedsaw,makeacircularcutaroundthearmoursatthebinderposition.Cut
U
throughonlyhalfthewidthofthearmourtoavoiddamagingtheleadsheathbelow.
•
earsuitablegloveswhileremovingthearmour.Liftandunwrapthearmourwiresafewat
W
atimeandbreakthemoffagainstthebinderbybendingthembackwardsandforwards.
•
emovethebinderandliftthearmourswithahackknifesotheyare90°tothecable.
R
Cleanoffalltracesofbitumenfromthewiresusingagastorchandapprovedsolvent
wipes.
U
N
C
O
N
TR
O
LL
ED
•
UK POWER NETWORKS 33KV JOINTING MANUAL I 2012
Section 3 I Page 11
Removing the Inner Bitumen Layer
•
earsuitableglovesforthisoperation.Scorearoundtheinnerbeddinglayerswithan
W
approvedknifeadjacenttotheverticalarmourstakinggreatcarenottoscoreintothe
underlyingleadsheath.
•
ttheopencableendliftthebitumenimpregnatedtextilelayerwithaknifeandunwrapit
A
backtotheverticalarmourposition,tearingitagainstthescorepreviouslymade.Theuse
ofagastorchmayassistthisprocess.
•
pplymoreheattothefinallayerofbitumenontheleadsheathandarmoursandwipe
A
offanyremainingtracesofbitumenwithapprovedsolventwipes.Theleadsheathand
armoursshouldbecleanandbrightafterthisprocess.
U
N
C
O
N
TR
O
LL
ED
3.3.3
Section 3 I Page 12
UK POWER NETWORKS 33KV JOINTING MANUAL I 2012
pplytwowrapsofblackmasticsealantaroundtheleadsheathbuttingupagainstthe
A
raisedarmours.
•
akeamarkwithaChinagraphpencil130mmfromtheendoftheoutersheath.Wrapa
M
lengthofcoppermesharoundtheleadsheathuptothe130mmmark.
U
N
C
O
N
TR
O
LL
ED
•
UK POWER NETWORKS 33KV JOINTING MANUAL I 2012
Section 3 I Page 13
aythearmoursdownoverthemastic,ensuringthatnonearecrossed,andsecurethe
L
armoursoverthecoppermeshareawiththetwowormdriveclipsprovided.
•
pplyalayerofPVCtapetothewormdriveclipstocoveranysharpedges.Positionthe
A
armoursealingsleeve30mmbeyondthearmouredgeandshrinkdownstartingatthelead
sheathendbeforeproceedingtowardsthecableover-sheath.
U
N
C
O
N
TR
O
LL
ED
•
Section3IPage14
UK POWER NETWORKS 33KV JOINTING MANUAL I 2012
Removing the Lead Sheath
•
leananddegreasetheleadsheathusingapprovedsolventwipes.UseaChinagraph
C
penciltomarktheleadsheath430mmfromtheoutersheathasindicatedontherelevant
jointinginstruction.
•
earsuitableglovesforthisoperation.Useanapprovedhackknifetomakeacircular
W
indentedringcutaroundtheleadsheathatthepencilmark,takingcaretoonlycutpartway
throughthesheath.
•
romtheopencableend,cuttheleadsheathlongitudinallytothecircularcutusingthe
F
appropriateapprovedhackknife.TakecarenottodamagetheCopperWovenTape(CWT)
below.
U
N
C
O
N
TR
O
LL
ED
3.3.4
UK POWER NETWORKS 33KV JOINTING MANUAL I 2012
Section3IPage15
pentheleadsheathupalongthelengthofthecutandcarefullyunwraptheleadsheath
O
againsttheringcut.
3.3.5
Removing the Copper Woven Tapes (CWT)
•
UnwindtheCWTandremovethecorefillerscarefullywiththesidecutters.
•
ewindtheCWTtightlyaroundthecablecoresatthecrutchpositionforadistanceof
R
20mmfromtheleadsheath,thencutandtieoff.Removeanysurplustapewithinsulated
sidecutters.
U
N
C
O
N
TR
O
LL
ED
•
Section 3 I Page 16
UK POWER NETWORKS 33KV JOINTING MANUAL I 2012
Removing the Insulation Screen
•
singanapprovedsolventwipe,removeanysurpluscablecompoundfromthescreened
U
coreinsulation.
•
arkthescreenpapersattheremovalpointindicatedintherelevantjointinginstruction.
M
Tieafinewirebinderaroundthescreensatthispoint.
•
arefullyunwrapthefirst50mmofthescreen.Securetheendofthecoreinsulationpapers
C
withnumberedphasetapematchingthenumeralpaper.Unwindtheremainderofthe
screentotheterminationpointandremoveitbyneatlytearingagainsttheappliedbinder.
N
C
O
N
TR
O
LL
ED
3.3.6
U
• R
emovethenumeralpaperandonelayerofpaperbelowtothesamepointasthescreen
papers,usingthesamemethodandmarkingthecoreswiththematchingnumberedphasetape.
UK POWER NETWORKS 33KV JOINTING MANUAL I 2012
Section 3 I Page 17
Note:Itisimportanttomarkthecoreswiththecorrectphasenumbersimmediatelyaftereach
numeralpaperisremoved.
ED
Removing the Insulation Papers
•
Onlyremovethepapersafterfittingtheclearbarriertubesdescribedinsection4.1.3.
•
arktheclearbarriertubeoverthecorepapersatthepointofremovalasindicatedinthe
M
appropriatejointinginstruction.
O
N
TR
O
LL
3.3.7
U
N
C
• U
singasharpknifecutaroundthecoreandthroughthepaperstakingcarenottodamagethe
conductorbelow.
Section3IPage18
UK POWER NETWORKS 33KV JOINTING MANUAL I 2012
Removetheclearbarriertubebypullingtowardstheendwithagentletwistingmovement.
•
oundingoftheconductorwithwaterpumporsimilarplierswillassistthisoperationand
R
willhelppreparetheconductorforinsertionintotheappropriateconnector.
•
Unwrapthepaperstothecutpositionandtearoffagainsttheclearbarriertubeedge.
•
Cleananysurpluscompoundfromthecableconductorwithanapprovedsolventwipe.
U
N
C
O
N
TR
O
LL
ED
•
UK POWER NETWORKS 33KV JOINTING MANUAL I 2012
Section 3 I Page 19
Three-Core HSL Paper Insulated Cables
3.4.1
Removing the Outer Serving or Sheath
•
arkthepositionoftheservingorsheathterminationasindicatedontherelevantjointing
M
instruction.
•
earsuitablegloveswhileremovingtheserving.Placeawirebinderaroundtheservingat
W
theremovalpointandscoreinfrontofthebinderusinganapprovedknife.
•
Removetheservingwiththeapprovedknifeandheatfromagastorchifrequired.
U
N
C
O
N
TR
O
LL
ED
3.4
Section3IPage20
UK POWER NETWORKS 33KV JOINTING MANUAL I 2012
Removing the Steel Wire Armour
•
Placeawirebinderaroundthearmourwiresatthepointofremovalasindicatedinthe
relevantjointinginstruction.
•
singanapproveddepthguardedorjuniorsawmakeacircularcutaroundthearmours
U
atthebinderposition.Cutthroughonlyhalfthewidthofthearmourtoavoiddamagingthe
leadsheathsbelow.
•
earsuitablegloveswhileremovingthearmour.Liftandunwrapthearmourwiresafewat
W
atimeandbreakthemoffagainstthebinderbybendingthembackwardsandforwards.
U
N
C
O
N
TR
O
LL
ED
3.4.2
UK POWER NETWORKS 33KV JOINTING MANUAL I 2012
Section 3 I Page 21
ttheopencableendliftthebitumenimpregnatedlayerwithaknifeandunwrapitbackto
A
thearmourcutposition.Removeitatthispoint,takingcarenottodamagetheunderlying
leadsheaths.
•
emovethebinderandliftthearmourswithanapprovedhackknifesotheyare90°tothe
R
cable.Cleanoffalltracesofbitumenfromthewiresusingagastorchandapprovedsolvent
wipes.
3.4.3
Removing the Bitumen Layer
N
C
O
N
TR
O
LL
ED
•
penoutthethreeleadsheathscarefullyandremovethebitumen/paperlayerandfillers
O
fromallthreesheathsuptothepointwheretheunderarmourbeddingremains.
U
•
Section 3 I Page 22
UK POWER NETWORKS 33KV JOINTING MANUAL I 2012
pplymoreheattothefinallayerofbitumenontheleadsheathsandwipeoffalltracesof
A
bitumenwiththeapprovedsolventwipes.
•
Theleadsheathsshouldbefreefrombitumenoncompletionofthistask.
•
uilduptheremaininginnerbeddingusingtheblackmasticfromtheThree-Coretransition
B
jointandtheHSLmoduletosuitthesupportring’sinnerdiameter.Fitthesupportringover
thebuilduptape,positioningit60mmfromtheupliftedarmours.
U
N
C
O
N
TR
O
LL
ED
•
UK POWER NETWORKS 33KV JOINTING MANUAL I 2012
Section 3 I Page 23
rapthelengthofsuppliedblackmasticbehindthesupportring,buttingitagainstthe
W
armourswires.Laythearmoursdownontotheringandsecurethemwithawirebinder.
3.4.4
Removing the Lead Sheaths
•
nlyremovetheleadsheathsafterfirstlyfollowingthenecessarystepsdescribedin
O
section4.1.5.(HSLmoduleapplication).
•
leananddegreasetheleadsheathsusingapprovedsolventwipes.UseaChinagraph
C
penciltomarktheleadsheathsattheremovalpointasindicatedontherelevantjointing
instruction.
•
seanapprovedhackknife,makeacircularindentedringcutaroundtheleadsheathat
U
thepencilmark,takingcaretoonlycutpartwaythroughthesheath.
N
C
O
N
TR
O
LL
ED
•
uttheleadsheathacrossfromtheopencableendtothecircularcut.Useanappropriate
C
approvedhackknife.TakecarenottodamagetheCopperWoventapebelow.
U
•
Section3IPage24
UK POWER NETWORKS 33KV JOINTING MANUAL I 2012
ED
• O
pentheleadsheathupalongthelengthofthecutandcarefullyunwraptheleadsheath
againsttheringcut.
Removing the Copper Woven Tape (CWT)
•
nwindtheCWTandcarefullyremoveitbycuttingitagainsttheleadsheathedgewithan
U
approvedknifetoleaveasmoothfinish.
3.4.6
Removing the Insulation Screen
N
C
O
N
TR
O
LL
3.4.5
arkthescreenpaperswithaChinagraphpencilattheremovalpointindicatedinthe
M
relevantjointinginstruction.Tieatwinebinderaroundthescreenatthispoint.
U
•
UK POWER NETWORKS 33KV JOINTING MANUAL I 2012
Section3IPage25
nwrapthescreencarefullytotheterminationpointandremoveitbyneatlytearingagainst
U
thetwinebinder.Removeanycarbonpaperbelowthescreentothesametermination
position,followedbytwooftheinsulationpapers.
3.4.7
Removing the Insulation Papers
•
nlyremovethepapersafterfittingthebarriertubingasdescribedinsection3.1.2.
O
Marktheinsulationpapersatthepointofremovalasindicatedintheappropriatejointing
instruction.Usinganapprovedsharpknife,cutaroundthecorethroughthepapersand
clearbarriertubetakingcarenottodamagetheconductorbelow.
N
C
O
N
TR
O
LL
ED
•
Removetheclearbarriertubebypullingtowardstheendwithagentletwistingmovement.
U
•
Section 3 I Page 26
UK POWER NETWORKS 33KV JOINTING MANUAL I 2012
Unwrapthepapersuptothecutpositionandtearoffneatlyagainstthebarriertubeedge.
•
Cleananysurpluscompoundfromthecableconductorwithanapprovedwipe.
3.5
Moisture Testing on Paper Insulated Cables
•
Fullpersonalprotectiveequipmentshallbewornatalltimesforthistest.
•
entlyheattheparaffinwaxcontaineronalowheat,insertthethermometerthroughoneof
G
therubbergrommetsinthetopandwaituntilthewaxreachesatemperatureof125°C.
U
N
C
O
N
TR
O
LL
ED
•
•
lwayshandlethepaperstobetestedwithgloves,asmoisturefromyourhandsisenough
A
togiveapositivetest.
•
Liftoutthebasketandplacethepapertapestobetestedinit.
UK POWER NETWORKS 33KV JOINTING MANUAL I 2012
Section 3 I Page 27
Thesamplesfromthefollowinglayersshallbetested:
•
Innerandouterbeltpapers.
•
Paperorstringfillers.
•
Innerandoutercorepapers.
•
Immersethebasketcompletewithpapersintheparaffinwaxbathandnotetheresults.
•
Ifthereisnoreactionfromthewaxoritfrothsslightly,thepapersaredryandthecableisfit
tobejointed.
•
Ifthewaxfrothsexcessivelyandacracklingnoiseisheard,thepapersarewetandthe
cableshouldnotbejointed.
U
N
C
O
N
TR
O
LL
ED
•
•
Removetheheatfromcontainerandleavetocoolbeforemoving.
•
hewaxcanbere-useduntilitstartstodiscolourandthereisnoneedtodisposeofitafter
T
eachmoisturetest.
Section3IPage28
UK POWER NETWORKS 33KV JOINTING MANUAL I 2012