I have stupidly taken down the light fitting in my hall and didn't note where the wires went. It has 2 lights and 2 switches. The wires are as follows 1, blue, brown, earth. 2, blue brown, earth. 3, blue brown, earth. 4 black wire with brown tape, brown, grey wire with blue tap, earth. The new light has live, neutral, loop and earth fitting. Any help is much appreciated.
You have 3 twin and earth cables and one 3 core and earth cable and no light fitting. I can tell you, of the 3 twin and earth cables, one is feed in, one is feed out, one is the switch cable. The question is which one is which and what is the 3 core and earth connected to? Without having a means of testing (Multi meter) all any one can do is guess, and since this will no doubt result in a large bang, I do not recommended it. Instead, I suggest you call in a competent person (It doesn't have to be an electrician) to do the job for you.
Thanks for your reply Mr White. If I get a multi meter to find out which is the feed in what way round would I connect them to the light socket. The light socket has earth, live, neutral and loop. Thanks
A multi-meter is not a magic wand. It is just at tool. With power off a bell and battery could be used to find out which cable goes to switch, in the same way as with a buzzer or ohm range on multi-meter.
I was really surprised when I went to do an 'A' level Physics, I wanted maths but if I did three it was £10 and just one over £100 so did three.
They provided the class with multi-meters, and the students were to measure volts and amps, and they managed to rupture 15 fuses in multi-meters. I thought the 'A' was for advanced?
And this is the problem as an electrician is seems easy, but clearly even advanced students could not follow what I thought were fool proof instructions, with a 12 volt power supply no problem, with 230 volt ac that is a different thing.
The forth cable can't help much, but first three likely one goes to the switch, and with the power off, and I mean total off at the consumer unit, then it is possible to put a meter/bell or other device across the brown and blue wires to test continuity and flick the light switch on/off until the switch wires are identified.
But forget to turn off power and then big bang is possible.
I worked out a truth table to enable testing without a meter, however make a mistake then again big bang, ionisation of the atmosphere is extremely dangerous and when I tried to relate how to use a truth table on here, I was banned for a time, as it is so easy to make a mistake.
I am concerned for your lack of understanding, things often look easy from afar, that is because the person doing the job is competent to do it, sadly you are not. I suggest you get someone in to do the job for you. Better safe than dead.
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