Boiler Wiring

[seftonbarn]

I have had a new boiler fitted today. One of the cables used is a 3 core and earth. They have put a red sleeve on the CPC and used that as one of the cables. Is that allowed? I thought all cable runs had to have a connected cpc.

 

[davesparks]

No that is not allowed because the cpc is not insulated. The only material surrounding the cpc is the outer sheath of the cable which is not designed or intended to be electrical insulation.
Also, although it won't affect this scenario, the earth core is often smaller than the live cores.


Strictly a green/yellow insulated conductor forming part of a multicore cable may be oversleeved and used as a live, but most people consider it bad practice.