tough one

[monty66]

can anyone help me please .im needing to put a new light in the ceiling.ive got 3 grey wire sticking out of the ceiling .how do i identify which is which.ive got one wire that is live and the other 2 are dead...i know one is the switch and one is the wire going to the other room....i have one of those testers where you touch the end with your thumb and it shows the live wire...ok where does the wires go..any help or some form of a pic would help a lot.. just the switched wire has no red sleve on it so im stuck..thanks monty

 

[kevplumb]

there is a diagram in the reference section at the top

 

[Adam_151]

The tester you have will be no help here, purchase a multimeter

Use continuity/resistance setting, with the power off, hold the multimeter probes onto each of the three cables in turn, get a helper to flick the switch back and forth a few times, when you have got the multimeter on the switch cable, it will read low resistance when the switch is closed, infinate resistnace (usually just displays digit 1) when the switch is open

 

[breezer]

the fact you have identified the 3 cables does help, now all you have to do is to discover that as mentioned there is a for refernce section

 

[Shammy]

This may help and i had a simular experience.

I had slightly thicker than normal grey wires in a wall socket (Not the big grey that holds all three) and I found that if you gentle split the end of the grey sleeve the coloured sleeve was underneath this grey sleeve.

 

[dingbat]

Yeah, but don't be fooled by the colours. Whoever wired it might just have used what was available and it's common to use black as the switched live; it should be sleeved in red, but more often than not it won't be.