Ceiling light fitting


Postby FlyingWolf » Sun Jun 07, 2009 5:17 pm

Hi guys (and Doreen),
Came across this forum today and hoping someone can help - I'm at my wits end. Doreen - sorry to piggy-back your post, but mine's a similar problem. Just about to call in the professionals before I kill someone (or myself more likely...). The scenario is this - I'm not an expert, hence the Jack and Jill terminology, sorry:

- I'm attempting to replace two hallway pendant ceiling light fittings, which involves re-wiring the ceiling roses.

- I'm pretty sure the problem involves the switch wire!

- Only one light circuit in the house seems to be affected, ie the downstairs lights.

- There are FOUR separate grey cables feeding [b]Lamp 1[/b]; THREE of these grey cables each contain THREE copper wires - one red, one black and one naked (no sheath). ONE cable contains only one red and one naked wire. Each of the grey cables appears to have a function - one is 'Power In', one is to/from Lamp 2, one is to/from lounge and dining-room lights, and the two-wire cable seems to be connected to the main landing light upstairs.

- For Lamp 1 I've connected via a (very small!) plastic junction box as follows: For each of the THREE grey cables - red (live) wires together, naked (earth?) wires together and black (neutral) wires together. The clear plastic flex down to the lightbulb contain TWO wires and I've connected one of these to the Live junction, the other to the Neutral junction. For the remaining two-wire grey cable, I've connected the red wire to the others - the naked wire is unconnected!!

- There are THREE separate grey cables feeding [b]Lamp 2[/b]; ONE of these cables contain THREE copper wires as before, the remaining TWO cables contain only one red and one naked copper wired. I haven't yet managed to work out what these cables go on to supply, if anything.

- For Lamp 2 I've connected the three red wires together, the three naked wires together and the one black (neutral) wire is on its own.

- I have TWO separate (but probably connected somewhere!) downstairs wall-mounted light switches: Switch 1 has two switches, one controlling the two hallway lights, the other the upstairs landing light. Switch 2 controls just the hallway lights.

- When I switch the main downstairs lights circuit on at the mains box, all downstairs lights work as normal, with the exception of the two hallway lights which are permanently on!!!

I'd appreciate any help anyone can give on this. The 2-wire/3-wire grey cabling is worrying - perhaps I just need to throw in the towel and get an electrician in.

Anyone got any ideas??

Cheers,

FW
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Postby bd3cc » Sun Jun 07, 2009 9:31 pm

Normally you would have 3 pairs(red and black), but you have four because you have 2 lights operated by the same switch, which I think are your hall lights, so this is not a problem.
The cable with red and earth, I suspect has had the black cut out because it was not needed. In terms of getting the lights working, ignore the earths,(unsheathed) as they must all go in the brass terminal at the side of the rose, nowadays they should be greenand yellow sleeved.
Have a look in the downstairs switch and see if the 2core cable appears there. If it does proceed as follows:
On your ceiling rose you should have 3 banks of terminals, connect the single red to the terminal with the brown flex wire, connect all blacks to the terminal with the blue flex wire, both are outer terminals. This should leave 4 red wires. You now need to identify which one goes to the other light fitting, (some form of continuitytester/multimeter helps here and is cheaper than a sparks call out). If you cannot identify it, trial and error comes into play, but essentially the red wire which goes to the second light fitting, needs to be in the terminal which has the brown flex, and all other red wires should be in the centre terminal, which is a dummy terminal, just used for connecting live in/ live out/ live to switch.
This will only work if my initial assumption about the single red is correct.
If it does not work, or if the light stays permanentl on, then you have the wrong reds in the dummy.
If this is the case post again, letting us know what cables you have at the switch on the ground floor,and we should be able to help further.
Remember to TURN OFF and stay safe.
HTH
bd3cc
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Joined: Wed Jan 30, 2008 8:02 pm


Postby FlyingWolf » Mon Jun 08, 2009 9:42 pm

bd3cc, sincere thanks for taking the time to reply :D I probably won't get a chance to look at this for a couple of days as I work long hours (the clue's in the username...), but I'll have a go and report back. Thanks again.

FW
FlyingWolf
Posts: 3
Joined: Sun Jun 07, 2009 4:18 pm


Postby FlyingWolf » Sun Jun 14, 2009 8:48 pm

Hi bd3cc,

Few questions if I may before I proceed further:

- when you mention 'the single red', which red do you mean? I've got four grey cables sticking out of the ceiling hole - all have red wires in them, just that three grey cables are three-wire and one is two-wire (as per the original post).

- all that came with each of the new lamps is what I think is a tiny 3-terminal junction box, ie bit like like a letter 'H', but with three top terminals and three bottom.

- I've removed the two-gang switch plate, and there are four grey wires inside it: two of the four grey wires each appear to comprise red (live), green/yellow (earth) and black (neutral) copper wires; the remaining two grey wires appear to only comprise live and earth wires, ie no neutral.

- using your advice and also the diagram here: http://www.diydoctor.org.uk/projects/li ... itches.htm I was proposing to proceed as follows:

- red wire (inside two-wire grey cable) connected to brown lamp wire via one of the three top/bottom junction connectors;
- three remaining red wires all joined together into middle top junction (dummy) connector - nothing connected to middle bottom;
- three neutral wires (each inside three of the four grey cables) connected to blue lamp wire via the last top/bottom junction connector;
- four earth wires (in each of the four grey cables) connected independently (ie outside of junction box) to earth wire supplied with rose.

Should this work do you think? No responsibilty on your part at all if I blow all the upstairs and downstairs circuits (!) but thought I'd check first to see if this sounded about right.

Sorry it's all so long-winded - the problem I guess with trying to describe and rectify problems via the web Many thanks though for all your help thus far.

Cheers,

FW
FlyingWolf
Posts: 3
Joined: Sun Jun 07, 2009 4:18 pm


Postby bd3cc » Tue Jun 16, 2009 10:19 pm

Very complex!
Dont assume that all black wires are neutral, particularly at a switch as they are often used a a switch live, and should be identified as such(red/brown tag, although this often wasnt done).
You really need a continuity tester to identify where each wire from the switch terminates.,
and in discussion only ignore earth wires as they must all be connected together for continuity.
bd3cc
Posts: 323
Joined: Wed Jan 30, 2008 8:02 pm


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