I want to change my light - my new light only has 1 neutral and 1 live wire but I have 2 neutral and 2 live as I have a pull cord switch. Do I need to keep both live wires separate, is this what shorts the fuse when I turn the light off
I presume one pair is the supply, the other pair goes to the switch. You should be able to work out the rest.
I guess that if the "fuse" is blowing it's possibly the "nuetral coloured" wire is the switched live from the switch and should have had the appropriate sleeving to indicate Live.
Beware that two red (or brown) wires and two black (or blue) wires are *NOT* two lives and two neutrals.
Some questions ...
Is this a single light in a ceiling rose?
Is this just switched by one pull-cord, and not switched from a wall-switch (sounds like a bathroom)
What colour wires do you see? (means we can stop referring to red/brown or blue/black if we know that).
Can you post some clear photos somewhere and send us a link here?
Depends on how your house is wired, by the sound of it, you have one cable with live and neutral coming in to the ceiling rose, then another cable that takes permanent live down to the switch, and has switched live coming back.
In that case the black/blue wire should have red/brown sleeving over it to indicate this, but it's common for this sleeving to be missed and if you connect both black/blue wires together thinking they're neutrals, you will get a fuse (or circuit breaker) that blows every time you turn on power.
Sounds like it, but best way forward is with a couple of photos ...
I can't see the OP, but I suspect you are right - this is the last light on the circuit, and so only has a cable in and a switch wire. Hence one of the neutrals will be lice or switched live.
This diagram should make it clear for the OP:
I simply did away with the whole problem when I rewired the house. All connections are made in junction boxes, accessible either in the loft or by lifting a floor board in each bedroom. Then a single piece of T&E comes through to each light fitting - no ambiguity and can simply be left in a piece of terminal block and pushed up out of the way, when decorating.
Probably because, at a glance, it all looks self evident. It's easy to overlook the over marking on the switch wire (if it is even present, which frequently it is not).
It's only when you then do the "obvious" thing of rejoining all the wires matching colour for colour that it goes bang :-)
Supposing the OP does not have a meter, can he sort this out?
(Sorry, I mean she. I promised someone that I would stop writing he and start writing she. I refuse to use they to refer to just one person.)
Given they are posting from HoH, chances are they will never be able to find the thread again anyway :-)
But yup, you can use the lamp itself. In this case there are only two "ends" the live feed from the circuit, and the drop cable to the switch. So turn the circuit off at the CU, and wire the lamp across the line / neutral conductors on one cable. Power the circuit back on. If the lamp lights, then you have connected it to the feed cable, and if it doesn't light, you have connected it to the switch.
Well with a name like Rach, it could be either, so I will stick with the Original Poster (OP) :-)
I guess it fuses when the light switch is turned into the on position and stays on when in the off position.
Good lateral thinking. :)
I guess that the OP is a bit confused. To be fair, if it's a pull switch, it must be unclear which is on and which is off.
Clearly, if the op wired a switch across live and neutral feed, then switch it on, the fuse will blow.
I guess that the switch is wired across the mains - and the OP is confusing the on and off positions. That way, in the real Off position, the lamp would be on, and in the real On position the switch would cause a dead short and blow the fuse.
Whenever I've put right people's mistake, it's because they've connected all the reds to one terminal, and all the blacks to another, so in this case the problem will be the switched live is connected to neutral.
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.