Regulations for Leaving Dead Wires in Walls

[Timmmm]

I have two lights on the wall. They are controlled by a standard switch on the wall. The wires are protected in the plaster by metal capping.

I intent to remove the lights, plaster over the wires and also disconnect them in the switch. I'll either leave the switch in place or possibly plaster over it.

Do the regulations have anything to say about leaving protected cables in the wall, and leaving disconnected 'dead' cables in an installation in general?

The only vaguely relevant section I can find is BS7671 section 522.6.101 which gives exceptions where *unprotected* cables are allowed (basically near corners and the ceiling).

I can't find anything at all about disconnected cables.

[kbrownie]

The regulations will only require the cables are to be made dead.
This would include live and neutral cables. I would disconnect ever thing upstream of the switch and then terminate all conductors at the wall lights and at the switch together.
You cannot plaster over the switch if conductors going to it are still connected to the live supply all live cable routes must be identified as per permitted safe zones. Standard metallic cable capping, does not qualify as mechanical protections.

[Timmmm]

Makes sense, thanks!

[kbrownie]

Indeed it does make sense. The aim is to make sure it cannot accidentally come live. Plus with the any RCD installation in circuit, they can trip even if the circuit is isolated. So you are best disconnecting the neutral as well at supply side. As earth-neutral trips do occur.