Double Insulated Singles

[Benny_Boy]

Not that simple Benny Boy, maybe my explanation didn't make it clear. The earthed conduit only runs within the wall, then the single double insulated will run on its own in the ceiling void to the lamp ceiling rose, approximately 4 metres away. The ceiling rose already has a line, neutral and earth supply, however the conduit was of insufficient width to accommodate the usual twin and earth switch wire. As I mentioned, the householder does not wish to disturb their beautiful wall.

Ah I see.

 

[Risteard]

I presume by "double insulated" you mean insulated and sheathed.

 

[Pinto Baz]

I presume by "double insulated" you mean insulated and sheathed.

Thanks Risteard, I've been going purple trying not to say that!

In a public building where there may at some time be a hearing aid induction loop fitted single cables can cause inteference if not run with their neutral or opposing flow live (return switch etc) Other than that I can't think of anythink that makes single sheathed cables any different to twin.

 

[Pinto Baz]

Just thought of something that might have prompted your original question. If you do run a seperate earth cable, that should be run adjacent to the cable that it protects. It's just for traceability

 

[topcop999]

Thanks Pinto Baz.... I think that was along the lines that I had read, at some point in my obscure studies! I don't recall what I had read stating why it should be run adjacent, but you have clarified that. Any idea what reg this is under?

Thanks

 

[Pinto Baz]

Sorry, No, just dragged it out of the grey matter, but I have come across it several times over the years. I doubt it will have a regs number, probably comes from a good practice guide. I'll let you know if I spot it again sometime soon.