Odd wiring for ceiling light

snowangel_2

I have more wires than I expected when coming to change my ceiling light fitting.

From the ceiling I have one cable red/black/earth and another which is red/red/earth?! The new fitting simply has L/N/E.

The house was re-wired when I bought it 10 years ago, so I can't remember if junction boxes were involved. The upstairs lights are on their own ring and this is the only light operated by one standard switch.

I've done a lot of my own wiring during the renovation, so I'm not a novice. But I have to say, I don't know what to do here as none of the others are like this.

http://i243.photobucket.com/albums/ff283/TheSnowRider/Wiring.jpg

The diagram is a bit pants, but hopefully a help. Any advice would be very much appreciated.

Lisa :think:

espresso

snowangel wrote: »

http://i243.photobucket.com/albums/ff283/TheSnowRider/Wiring.jpg

The diagram is a bit pants, but hopefully a help. Any advice would be very much appreciated.

Lisa :think:

The right hand "Mains" in your diagram should say Switch.

weekendwarrior

This should make it easier to understand-

ceiling rose wiring

HugoSP

If you don't fully understand lighting circuits I would have a good look at the site that Weekendwarrior posted.

To the uninitiated they can be confusing, but they are actually designed to make the installation simple, and adding extra lights should be easy.

Ignore the earth for a while, then imagine the main red and black (old colours) as hopping from one light to the next. If you undo most roses in the house you may find two sets of red and black wires joined. These are your incoming and outgoing loops. The third set is going to your switch.

You may find a total of 3 reds joined together, then one black with a red sleeve on it (it should have one) joining onto the brown on your light fitting, then the blue wire from your light fitting will be connected to the 2 black wires that form the neutral part of your loop.

The third red and the black with the red sleeve form the part of the circuit that goes to and from your light switch.

If I've confused you please PM me.

snowangel_2

You may find a total of 3 reds joined together, then one black with a red sleeve on it (it should have one) joining onto the brown on your light fitting, then the blue wire from your light fitting will be connected to the 2 black wires that form the neutral part of your loop.

The third red and the black with the red sleeve form the part of the circuit that goes to and from your light switch.

Yes I'm still a little bit confused! lol (pm'd you too)

I had already looked at weekendwarrior's link, but my wires don't seem to match any of those configurations. Excluding the earth wires, the diagrams show three contact points. I'm assuming they represent live, neutral and loop as per my current fitting, but the new one only has live and neutral points. There's no option for a loop.

If we forget the earth wires as there's no question of where they go..... I only have four wires left.

None of my red's have a black sleeve or vice versa, and to be honest,I don't understand why the black wire currently goes to live, while 2 reds go to neutral. I thought the red/brown wires were always the live ones?? Oh dear, maybe I should concede and call in a sparkie!!

Ok, it's two hours after I first started to write this.... I've had a few glasses of wine, and it all seems very obvious to me now (if I think of the word "switch" instead of "loop" (thanks to esspresso)).....

I'm thinking I could put the black to neutral, the two middle reds together in a connector and stash them up in the ceiling, and then outer right red to the live. Thus completing a circuit....??

Although that appears logical to me right now, don't fret... I'm not planning to attempt anything until I'm sober again! ha ha
:beer:

I'll maybe give that a go tomorrow anyway (and stand well back!!). I'll post to say if it works or not.

Thanks
Lisa


Hmmmm..... if you don't hear from me, assume it didn't go well. Ha ha :A

ormus

the reason why some black wires are in fact live, is cause usually the switch cable (ie the cable from the rose to the switch and back again) has a black and red wire inside.
hence when you flick the switch on, the black wire then becomes live. hence it should have a red marker on it.
(ie a piece of red tape).

so when working on any live circuits (which you shouldnt) treat all wires as live, no matter what color they are!

believe me, you only get caught out once!
and it dont half hurt!!!

espresso

More information here which may help.

snowangel_2

Hey hey!!

So sorry I didn't let you all know how it went.

Well I woke up the following day and still thought my logic of the previous night would work. So I'm very pleased to say, YES IT DID..... YAY!!

I still have no idea why I had the wires that I did, but I've now put a black sheath on one of the blacks so it will make more sense to me if I need to change it in the future.

Thanks for all your advice. I know I worked it out for myself, but you all helped me think it through.

L