33kV Cable Terminations – Raychem Heat Shrink Terminations (VSLP9 Switchgear)

Published 26 Jan 2018

• Application: 33kV Cable Terminations –  XLPE Cables Into VSLP9 Type Switchgear
• Cable Jointer: Craig Kilkenny – EHV Cable Jointer / Fitter
• Product Category: MV HV Power Cable Terminations

• by Chris Dodds T&D - estimated reading time 5 minutes   

33kV Cable Terminations Installation

Here, high voltage substation cables are shown connected and terminated into switchgear using 33kV cable terminations.

The copper earthing tapes are used to bond all of the cable glands together which are providing mechanical retention to the 33kV high voltage power cables.

The earth tapes are clamped and attached to the substation earthing system as they are insulated from the 33kV cable box and high voltage oil-filled switchgear. The whole bank of HV switchgear is insulated from the ground and has its own earth which runs through a Current Transformer (CT) for protection reasons – the separate ‘frame earth’ is painted green in the photograph below. The stand for the cable cleats was also bonded to the substation earth. As there is a steel sandwich plate fitted to the front of the wooden cable cleats the threaded bar used is stainless steel to avoid circulating currents.

Sealing Cable Ducts 33kV

Client specified expanding foam has been used to seal the substation cable ducts within the high voltage substation – outside the substation the 33kV cable ducts were effectively sealed using a specified system to provide certain protection against water ingress and gas migration using recognised systems such as the CSD RISE duct seal or Filoform Filoseal re-enterable cable seals.

The insulating oil is usually heated before the high voltage cable box is dismantled by venting it above and heating with halogen heaters.

Stripping & Terminating 33kV Cables

The 33kV cables were stripped using the correct cable jointing tools – the PVC cable sheath was thoroughly stripped from the high voltage power cable using the Boddingtons “plough” type sheath stripper. The cable jointer then removed the XLPE insulation cleanly and without damaging the cable using Alroc LH2 tool suitable for cable stripping HV cables up to 60mm.

Finally, Alroc CWB 18-60 tool was used to remove the bonded semicon from the cable – the “blue tool” manufactured by Alroc is preferred by jointers for working on medium/high voltage power cables where a clean square cut of the semicon without jagged finish is vital to the long term reliability of power cable performance.

Poor cable jointing skills with respect to MV-HV cable preparation can create future cable failure potential – it is critical a skilled jointer uses the correct cable tools to prepare MV-HV cables before installing joints, terminations or connectors up to 33kV.

Comments from fellow HV cable jointers:

Jimmy Nicklin: “Nice job Craig Kilkenny. I did a nine bank of these 15 years ago and is quite the breakdown and remake to do.”

Dean Wilson: “Nice neat work Craig Kilkenny and yes I agree Jimmy Nicklin it’s getting the old oil out that’s a job in itself!”

Andrew Brezovszky:  “Very neat 33kV cable terminations !”

Thorne & Derrick International

Should you require any assistance with the selection or specification of heat shrink terminations to suit 33kV high voltage power cables please do not hesitate to contatct us.

T&D distribute the most extensive range of MV & HV Cable Joints & Terminations, Cable Installation Accessories & Cable Pulling Equipment – we service UK and international clients working on underground cables, overhead lines, substation earthing and electrical construction at LV, 11kV, 33kV and EHV transmission and distribution voltages.

• Key Products: MV-HV Cable Joints & Terminations, Cable Cleats, Duct Seals, Cable Transits, Underground Cable Protection, Cable Spikers, Cable Jointing Tools, Feeder Pillars, Cable Ducting, Earth Tapes, Electrical Safety, Cable Glands, Arc Flash Protection & Fusegear.

• Distributors for: 3M, ABB, Alroc, Band-It, Catu, Cembre, Centriforce, CMP, Elastimold, Ellis Patents, Emtelle, Furse, Lucy Zodion, Nexans Euromold, Pfisterer, Polypipe, Prysmian, Roxtec.

LV – Low Voltage Cable Joints, Glands, Cleats, Lugs & Accessories (1000 Volts)

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