simple yet confusing light fitting change

williams83 · Oct 1, 2015

Sorry if this is in the wrong section, but I'm having a right mare with a new light fitting.

Forgive me if I'm being stupid but this is confusing me. (Possibly something simple)

So I have purchased a new light fitting to install (not usually a problem). However when taking off the old ceiling rose I have noticed three incoming cables. These are looped and feed the lounge and hallway.

I have 2 black/neutral, (into neutral) 3 red/live (into loop) and 4 earth. Nothing labelled as switch live. Two are standarf T&E, but the other has 1 live and 2 earth ?

On the new light fitting I have the normal L,N,E into connection blocks.

Based on wiring the new light how the old one was, I cannot get them to work.

Can someone advise the error?

Thanks I'm advance.

telectrix · Oct 2, 2015

identify the switch cable using a meter set on ohms. then work it out .

amlu · Oct 2, 2015

the one with 2 earths may be a twin and earth with insulation messed up.

williams83 · Oct 2, 2015

It's a new property I've just brought so didn't have a meter to hand.

The thing is, 3 lives were looped, two neutrals are in with the Neutral but there isn't a neutral/switch live. Looks as though there is a neutral missing, and the fact u have one imcoming with 2 earth's and and live is the confusing part.

The picture below is exactly how I removed the light (left) and how I wired the new light (right) only difference being the layout is like for like minus the switch live.

Marvo · Oct 2, 2015

The diagram above is correct for a standard wiring scheme but with lighting there's numerous variations that can occur so your wiring may be different. You're going to have to manually identify each cable and wire and work out the correct connections from there but without test equipment it's not going to be something you can do yourself. I'd strongly suggest it's a job you'd be better getting a sparky to help you out. If it all worked fine originally and you've not disturbed to upstream or downstream wiring it should only take s short time to sort it out with the right test equipment.

williams83 · Oct 2, 2015

OK thanks all for the reply. I'm just a trainee at the moment. However have spoken to a more qualified electrician that will assist with the correct tools.