Wiring colours

slpxxxx

I have a cable in my loft which has the following colour cables inside, which wire does what, any ideas please? Colours are Brown, Blue, Yellow (and a bare copper earth wire). 

slpxxxx

BTW I was looking to tap into this were for a loft light....

Risteard

Sorry to say it but if you don't know what you're doing, then don't do it. 

Also I suspect you mean that it's red, yellow and blue. 

Carrot007

So 3 + earth (which should have shielding on when exposed). Not very normal and your (and tards colours do not make sense).

Either you are in a multi phase (3 + earth would be the old 2 phase not often seen) property  or it is some bodge.

However since you do not seem to be able to prod it with a multimeter and see what is going on then to oddlyu agree with get a electrician in guy I would say indeed get someone in! I did for my living room light as it was a mess on many wires and well without removing the ceiling too much effort for me. However lights in the loft. Easy. If it all looks good. Many quesions not answerd also. But if you had a clue you would have given the information yes?

fenwick458

i'm guessing it's actually red/ blue/yellow, the red may have faded a bit...
but I'm afraid I can't answer your question, there is no set rule for what to use each colour for when using 3 core + E in domestic, it'd be upto the electrician who wired it, i'd need more info. if you tell me where the cable goes between, I could "guess"

Carrot007

fenwick458 said:

i'm guessing it's actually red/ blue/yellow, the red may have faded a bit...
but I'm afraid I can't answer your question, there is no set rule for what to use each colour for when using 3 core + E in domestic, it'd be upto the electrician who wired it, i'd need more info. if you tell me where the cable goes between, I could "guess"

Or as I said test it like anyone doing such a job should be able to.

Owain_Moneysaver

Could be 2-way switching, or lighting circuit with interconnected smoke detectors on. 
You'll need to check at fittings or the consumer unit.
Warning - if you connect something wrongly to a smoke detector interconnect you could blow all your smoke detectors. They're expensive to replace. 

TELLIT01

If the OP doesn't even know which wire does what it would be insanity to do the job themselves.

452

Owain_Moneysaver said:

Could be 2-way switching, or lighting circuit with interconnected smoke detectors on. 
You'll need to check at fittings or the consumer unit.
Warning - if you connect something wrongly to a smoke detector interconnect you could blow all your smoke detectors. They're expensive to replace. 

How do you suggest the OP checks the consumer unit? Nothing will give any indication of what the wired is with the cover in place. 

fenwick458

Carrot007 said:
Or as I said test it like anyone doing such a job should be able to.

is that what you said? I honestly had no idea what to make of your post it just looked like a load of waffle. 

Carrot007 said:So 3 + earth (which should have shielding on when exposed). Not very normal and your (and tards colours do not make sense).

What? what sort of sheilding should be on it when it's "exposed"
what are "tards colours"

Carrot007 said:

Either you are in a multi phase (3 + earth would be the old 2 phase not often seen) property  or it is some bodge.

What? "Multi phase" in a domestic house. oh right then

Carrot007 said:

then to oddlyu agree with get a electrician in guy I would say indeed 

Oh yes this clears it up....

mwarby

if its near a bathroom, it could also perhaps be for the extractor fan