Fitting a light...

[heather2008]

Hi everyone,

I've got a problem fitting a ceiling light and the wiring is really confusing me, can anyone help me?

Most lights I've fitted have one or two brown and blue wires coming from the ceiling (along with the earths) and I put both together into the light fitting. This light has four grey cables:

3 have: 1x earth 1x blue 1x brown
1 has: 1x earth 1x grey 1x black

What am I supposed to wire the grey and black to?

I've tried every combination but it doesn't seem to work! With the blue and brown wired in normally the light goes on and stays on when I try to switch it off! Should I wire the random grey cable into it somehow? I'm wiring the four wires into a connection box then having a single wire coming from that to the light as it's easier to work with.

Many thanks,

Heather

 

[Chappers]

Normally in the light fitting you have 4 connector strips. One has three terminals for the lives (live in, live out to next fitting on the radial, live out to switch), the next has three terminals (neutral in, neutral out to next fitting on the radial, neutral to bulb holder), the next after that also has three terminals (earth in, earth out to next fitting on the radial, earth to switch) and the final connector strip has two terminals (switched live from switch, and live feed to bulb holder).

If you have four flat, grey twin & earth cables, then I'd imagine that one is the supply in, two are supplies back out feeding other light fittings, and the one with grey and black is the cable to the switch, one being used as the live and the other the switched live which feeds the bulb holder.

I'd check by taking the switch off the wall and ensuring you have the black and grey conductors going there. Remember to work with the mains off, even when checking the light switch. If you're still unsure, I'd advise getting someone in to do it. Not worth taking risks.

 

[assured elec]

Is there a extractor fan in the room ?

 

[heather2008]

thanks for the reply,

i've had a look behind the switch and there's just one black and one brown wire connected to it (the brown goes into the switch next to it, then the brown wire from that switch goes into the wall and to the external light (does that make sense?!). so there's no grey wire to the switch that controls the problem light.
i'm sorry but i'm not technically minded enough to fully understand everything you put in the reply, i followed most of it though!
after re-reading my post i've made a mistake in my description-
from the ceiling is 4 cables- three of the cables have 3 wires, the normal green/yellow, brown and blue. the other cable has four wires- green/yellow, brown, grey and black.
at the moment, what i've tried, is all 3 blue wires into one connector strip and the 4 brown into another one with all 4 earths connected to each other and taped up. that leaves the black and grey doing nothing but dangling there! like i said this combination works but i can't turn the light off!
any ideas what combination of wires in which holes will work?!
thanks again,

heather

 

[assured elec]

the 3 core+ earth sounds like its running an extractor fan , tape this up safely , deal with that when your lights are on .

now you have 3 twin and earths , one of these will be a switch wire , did any of the blue cables have brown or red tape on them?

 

[heather2008]

thanks alot for the help, i really appreciate it.
there is an extractor fan in the bathroom, this light is in the hallway so it could be that yes.
sorry i don't understand what you mean by core and twin - is the twins the blue and brown wires? and the core grey and black? apologies about making as basic as refering to them as colours...!
no, none of the wires had brown or red tape on them. the black wire had a black sleeve on it, or may have been the grey wire.
heather

ps...
"the 3 core+ earth sounds like its running an extractor fan , tape this up safely , deal with that when your lights are on"
so the cable with grey, black, brown and earth should just be taped up and not wired into the light fitting at all?

 

[LukeScotty]

start from scratch in my opinion, take the 3 core outta the picture, find ur switch live (single cable running from switch to fitting) and perminate live,

 

[KFORDHUNTER]

If we are still talking about it know its probably better you contact an electrician, he should sort it out in under half an hour.

 

[heather2008]

kfordhunter - that's not going to happen, this light has made this personal and it will not defeat me...

good advice luke, i've started again. i'm assuming that one of the brown wires is the switch live, and i think i've found which one it is. what do i do with this now i've located it? how does it get wired into the fitting?

thanks again guys,

heather

 

[andyb]

Heather, the best advice you’ve had is from kfordhunter, I should pay heed to it.

Luke, you’ve taught Heather to identify the switch line, now what? I assume you are going to take her through the procedure for fitting the light. Ok, are you going to teach her how to test the earths that are obviously there to confirm that they are actually connected to the met. Are you going to take her through the relevant tests to establish Zs and every thing else that goes with such a simple job. I see also that she will be reconnecting a fan that is fitted in a special location. General advice is fine but to take an unqualified person step by step through an admittedly simple procedure like changing a light fitting is a little bit risky to say the least.

 

[actionjack]

Agree with andyb 100%

 

[jeremy]

What part of the country are you in Heather? I have an unpaid week off work , if you're local I might be able to help. I am so bored! Please don't do it yourself without at least understanding what each cable is doing

 

[mrloy99]

hello heather.If you are still determined to sort this out yourself--to me it sounds
like,as at your switch you have a brown wire and a black wire,this 3core+earth(cores refers to the number of cables inside the outer cover of the grey cable)is your live to switch and return to lightfitting,to bring your light on when then switch is on.So your black wire would then be the switched live and should be connected to the brown wire on the light fitting.If you look closely at the cable at the switch you will probably
see that the inner core grey wire has been cut off and is not being used at all,so at the ceiling position,this grey should be taped up out of harms way. Now this brings me to another concern.Your light fitting is in the hall,is it the only light in the hall or is there one that is supposed to come on at the same time.(If there is two lights on the same switch one of these brown wires could be a 'loop switch wire")So initially
I would connect the browns together.,the blues together,earths together.Let us know what happens.

 

[assured elec]

hello heather.If you are still determined to sort this out yourself--to me it sounds
like,as at your switch you have a brown wire and a black wire,this 3core+earth(cores refers to the number of cables inside the outer cover of the grey cable)is your live to switch and return to lightfitting,to bring your light on when then switch is on.So your black wire would then be the switched live and should be connected to the brown wire on the light fitting.If you look closely at the cable at the switch you will probably
see that the inner core grey wire has been cut off and is not being used at all,so at the ceiling position,this grey should be taped up out of harms way. Now this brings me to another concern.Your light fitting is in the hall,is it the only light in the hall or is there one that is supposed to come on at the same time.(If there is two lights on the same switch one of these brown wires could be a 'loop switch wire")So initially
I would connect the browns together.,the blues together,earths together.Let us know what happens.

Think you have this wrong mate , the poster has said there is one cable with 3 cores and earth , not mentioned a core being cut out.. the 3 core will be running the toilet extractor , the 3 twin an earths in new colours will be loop in loop out and switch wire.

not trying to catch you out as you obviously know your stuff , this is just the way i see it.....




cheers

ste

 

[sivoodoo]

its all getting a little confusing isnt it...
call an electrician, be safe!