Pot Ending LV SWA PVC Sheathed Service Cables – Engineering Guide UKPN

Published 24 Nov 2020

• uploaded by | Chris Dodds (Sales Marketing Manager at Thorne & Derrick)

PVC Sheath Removal

• Clean the outer PVC sheath of the cable and abrade for 60mm with a rasp, to form moisture seal

• Remove 300mm of the outer PVC sheath
• Refer to the UKPN LV Manual Section 3.5.1 removing the outer PVC Sheath

Steel Wire Armour Opening

• Apply a wire binder around the steel wire armours 25mm from the outer sheath cut at both end of the cable
• Install the service temporary earth bond, consisting of a length insulated braid and two constant force springs, around the steel wires between the sheath removal point and the wire binders
• Using a plastic small wedge and insulated side cutters, cut the individual armour wires around in the centre of the cable joint

• Fold the wires back against the binder at both ends, so they are away from the working area of the cable joint
• PVC tape the cut steel wire armours to the PVC either side of the cable joint

PVC Bedding Removal

• Shroud the exposed armours and the continuity bond connections at both cable ends
• 25mm from the folded back armours, ring round the PVC bedding with a plastic Mini-Hepnyf
• Note: The Mini-Hepnyf needs to be new with a clean sharp edge to ensure that the bedding can be removed without causing damage to the insulation on the cores below
• Remove the bedding between the two bedding removal points, by applying gentle heat to the bedding
• Note: Excessive heat will make the bedding too soft and make it more difficult to remove. Refer to Section 3.5.1 of the LV Jointing Manual
• If the bedding layer is difficult to remove or if it is bonded to the core insulation, then the cable shall be made dead, prior to continuing with the bedding removal process

Core Cutting & Capping

• Refer to Section 3.7.3 of the LV Jointing Manual
• A PILC two or four core heatshrink pot end kit should be utilised depending on the number of cores in the SWA cables
• Once the cores are exposed, test the cores to prove live and neutral
• Insert a plastic cutting wedge between the cores and cut each live core in turn centrally and install a temporary cap

• Finally cut the neutral core and install a temporary cap

• Cut each of the live core(s) 70mm from the bedding and install the heatshrink cap provided in the joint kit, as per Section 4.10.4 of the LV Jointing Manual
• Cut each of the neutral core 70mm from the bedding and install the heatshrink cap provided in the joint kit, as per Section 4.10.4 of the LV Jointing Manual

Completing The Pot End

• Remove the temporary earth continuity bond and any temporary shrouding
• Allow the heat caps to cool, apply two half lap layers of PVC tape over the cores
• Fold the steel wires back over the previously applied PVC tape, trim them to the same length as the phase and neutral cores
• Apply two half lap layers of PVC tape over the wire armours and tinned copper mesh, make sure all sharp edges are covered

• Slide the mastic coated heatshrink tube over to the 60mm of sheath abrasion and shrink into place ensuring a good water seal. As per Section 4.10.4 of the LV Jointing Manual
• Slide the mastic coated large heat shrink cap over the previously shrunk tube and shrink in place, starting at the sealed end, before working towards the open end. To prevent the
  cap sliding off hold in place using an insulated wedge

• Allow to cool before fitting the yellow plastic safety bag in place

• Once the pot end has cooled, place the yellow bag over the joint, ensure that the hazard symbol is on the top and fix in place with PVC tape

LV HV Electrical Cable & Power Distribution Systems up to 66kV – we are highly customer responsive and absolutely committed to providing a world-class service.

Contact our UK Power Team for competitive quotations, fast delivery from stock and technical support or training on all LV-HV products.

Key Product Categories: Duct Seals | Cable Cleats | Cable Glands | Electrical Safety | Arc Flash Protection | Cable Jointing Tools | Cable Pulling | Earthing | Feeder Pillars | Cable Joints LV | Joints & Terminations MV HV