MegaSack DRAW - This year's winner is user - rgwb
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Evening,
I've just come to replace the old ceiling mounted light fitting in the bathroom. It's an old house, most wiring is still red/black colours and solid copper.
The wires poking out the ceiling are doubled up, i.e. two outer sheath, both red twisted together, both blacks and both earths. Is this normal? Do I need to keep both wires wired into the fitting?
I've just left them like that and replaced with a new fitting. On turning the consumer unit back on, the lights came back on, all good, but trips the breaker when I turn them back off. If I turn the consumer unit back on again with the lights off, it trips. Any ideas?
Cheers,
Ed
http://www.ceilingrosewiring.co.uk/
Are you 100% they were paired up colour for colour ?
Id check another light fitting to see how they are wired up.
Iirc my red and black wiring wasnt paired red red black black and reading it was a common mistake to make when replacing the light fitting.
If it's anything like my house, the colour code in use is "whatever we had most of at the time."
Get an electrician in before you electrocute yourself.
Oh god.
Single light fitting so didn't think It'd be quite so complicated.
Lives were definitely twisted together, as were earths. Neutrals might not have been. No idea which is the switch wire.
check the switch; if there is a red/black pair in there then the way you've got it wired the switch is effectively shorting out the whole lighting circuit and the bulb is permanently connected from live to neutral.
It should be connected with the two reds together (not connected to the bulb at all) and the bulb connected between the two black wires.
Although; without seeing it I can't guarantee it; but that's the most likely configuration from what you've described....
It doesn't really matter which one the switch wire is tbh; though if you can identify it might be worth putting a piece of red heatshrink / electrical tape on it to mark it as so.
See now that sounds more plausable to me.
If was me id pop switch off wall and do a continuity test between the neutral in switch an each on the roof to figure it out
If that sounds like gobbledy gook then get a spark
How ever as pointed out long as they on seperate sides of lamp itll be good
who needs a continuity tester; that's what neon screwdrivers are for 🙂
*don't follow all my advice unless you promise not to sue 😉
OK,
I've connected the earth to the light fitting earth, left the two lives twisted together, and connected one each of the two neutrals to the live and earth of the light fitting.
This works fine and doesn't trip but "shouldn't" be right. If it works does that mean it's ok? Pretty sure this wasn't how it was connected before.
It's fine; it means your light is the last connection on the lighting circuit. live and neutral in from the previous ceiling rose; then a red and black pair to the switch. The returning black from the switch is a switched live.
So both reds are permanent live (hence connected together)
one black is permanent neutral
one black is switched live
hence bulb across the blacks.
Great.
Thanks guys, brilliant and timely advice as always!
Ed