Christopher Spencer asks this question, which concerns whether PVC bedding will give sufficient mechanical protection to cable run from a home to a garage. It has been answered by BASEC (Theme – Cable, Wiring and Wiring Accessories):
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Question: I’m installing an electrical supply to a garage consumer unit via three-core SWA cable. I intend running twin & earth cable from the house consumer unit to a galvanised adaptable box some 500mm in length. Then I will gland the SWA cable and run it to the garage from the adaptable box.
As an alternative, providing the galvanised box is earthed, is it possible for the SWA conductors with PVC 'bedding' to continue the 500mm length from the galvanised box, clipping direct to a wall, and then enter the consumer unit?
Once entering the consumer unit, the PVC 'bedding' can then be stripped back before terminating.
Does the PVC 'bedding' provide similar and/or sufficient mechanical protection as that of the PVC sheathing of the twin & earth cable to allow it to be clipped direct?
Answer: No, the bedding layer does not provide mechanical protection.
Also, the armour needs to be effectively earthed. Note that the main earth connection may well be at the consumer unit.
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