Yes, it's me again!

When I wire my new extractor fan in the bathroom, I will be installing a fan
isolator switch outside the bathroom.

I will need to bring the following both in and out...
Permanent live
Switched live
Neutral
Earth

The only three core and earth I can find has the colours
Brown
Black
Grey
(Bare earth)

This, I understand is the colours for three phase wiring?
(Although Screwfix suggest it is used in two way lighting)

My house has both the old colours (Red/Black) and the new (Brown/Blue)
(With the appropriate sticker on the consumer units, of course)

Can my new circuit use both the old and the new colours in the same cable,
like this...
Brown - Permanent live
Black - Neutral
Grey - Switched Live, sleeved in red or brown

If not (and I expect not) do I just sleeve with blue and brown each end of
the cable?

Ta!

--

Sparks...
(Not an electrician)

Sparks wrote:

The only three core and earth I can find has the colours
Brown
Black
Grey
(Bare earth)

This, I understand is the colours for three phase wiring?

Correct, just as old-colour 3&E cable had red, yellow, blue (the old
3-ph colours).

(Although Screwfix suggest it is used in two way lighting)

Also correct, all cores sleeved brown, of course.

Can my new circuit use both the old and the new colours in the same cable,

No, you shouldn't be using old colours at all now. In particular you
should use the grey core (sleeved blue) for neutral, not the black.

like this...
Brown - Permanent live
Black - Neutral
Grey - Switched Live, sleeved in red or brown

So no, like this:

- Brown - Permanent live
- Grey - Neutral (sleeved blue)
- Black - Switched live (sleeved brown)

If not (and I expect not) do I just sleeve with blue and brown each end of
the cable?

Sleeved at the ends and any intermediate connection points.

--
Andy

"Andy Wade" wrote in message
...
Sparks wrote:

The only three core and earth I can find has the colours
Brown
Black
Grey
(Bare earth)

This, I understand is the colours for three phase wiring?

Correct, just as old-colour 3&E cable had red, yellow, blue (the old 3-ph
colours).

(Although Screwfix suggest it is used in two way lighting)

Also correct, all cores sleeved brown, of course.

Can my new circuit use both the old and the new colours in the same
cable,

No, you shouldn't be using old colours at all now. In particular you
should use the grey core (sleeved blue) for neutral, not the black.

like this...
Brown - Permanent live
Black - Neutral
Grey - Switched Live, sleeved in red or brown

So no, like this:

- Brown - Permanent live
- Grey - Neutral (sleeved blue)
- Black - Switched live (sleeved brown)

If not (and I expect not) do I just sleeve with blue and brown each end
of the cable?

Sleeved at the ends and any intermediate connection points.

--
Andy

Thanks Andy - It just seems so wrong using a black wire for a live!

Sparks wrote:

It just seems so wrong using a black wire for a live!

Yes, it does go against the grain, but it's exactly what they do in much
of the rest of the world, and we're just going to have to get used to it.

--
Andy