I have a ceiling light that can be switched on via 2 switches. When I switch it on either one the main breaker trips. Its quite simple wiring inside so I thought that there might be a problem with the transformer inside. I took down the light and replaced it with a known working identical model but the same thing happens. There has been no drilling or any other work done that might affect the wiring so does anyone have any idea of where I could test next?
Light switch trips main breaker
- Thread starter 19nffc77
- Start date
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What is this breaker which is tripping - an MCB (probably labelled B6) or an RCD (with a test button)?
Kind Regards, John
Thanks for replying gents, it's labelled a residual current operated circuit breaker with a test button.
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Can you post a pic of the device that is tripping? A normal RCCB trips on earth leakage, an RCBO trips on earth leakage or overcurrent.
What is under the green tape?
Are the wires clear of the fixing screws?
You shouldn't have that much copper showing on the terminal block, the wire sheaths ought to but up to the terminal block so there is none showing.
What is under the green tape?
Are the wires clear of the fixing screws?
You shouldn't have that much copper showing on the terminal block, the wire sheaths ought to but up to the terminal block so there is none showing.
Firstly there is too much copper on show - there should be none.
Does the light trip the RCD when it is hanging down like it is now?
Have you checked that all the bulbs work - or have tried it without any bulbs in at all?
Have you checked that the other cables are not protruding from the green taped terminal strip?
Who actually wired the lights like they are now?
Does the light trip the RCD when it is hanging down like it is now?
Have you checked that all the bulbs work - or have tried it without any bulbs in at all?
Have you checked that the other cables are not protruding from the green taped terminal strip?
Who actually wired the lights like they are now?
It's the breaker furthest to the left that trips.
As it is now the breaker will trip if I flip the switch.
When I first moved into the house this is what it was like. Because I had a lot on instead of getting it fixed I just disconnected the wires and put some insulating tape on the ends then put the light back so that it is in place but didn't work and would not trip the breaker. I've just got round to attempting to fix it so I don't know who originally did the work. There is quite a lot of things wrong so I assume the previous owner did it as he appears to be a sub standard handyman.
The wires are clear of the fixing screws.
Underneath the green tape is a bare copper wire that is coming out of the same grey sheath as the red wire. What is it?
I have just taken all of the bulbs out and tried again and the same thing happened.
If I cut the copper wires back and try it again and the same thing happens could there be something wrong with the switches?
Do I take it that there are other lights on the same circuit (i.e. which can be switched off by the sme 'lights' breaker) which are working satisfactorily?
Kind Regards, John
Kind Regards, John
Yes there's quite a few others that work fine. I have just taken off one of the switches and although you can't see it in the photo the word 'top' is facing downwards. Am I right to assume this could be the cause even if the other light on that same switch works ok even being upside down?
Upside down, per se, does not matter. What matters is whether it is wired correctly, and we can't really tell that from the picture. Have you looked inside the other switch to make sure that there's nothing obvious awry?
Kind Regards, John
Yes I've looked in both but the only thing that seemed possibly wrong to me was the 'upside down' switch.
The single switch you can see where the wires go but on the double one there are red wires going in to top L2, bottom L2 and L1 and then a link between the 2 L1's. There is a black wire going in to the top L3 and nothing in the bottom L3.
The single switch you can see where the wires go but on the double one there are red wires going in to top L2, bottom L2 and L1 and then a link between the 2 L1's. There is a black wire going in to the top L3 and nothing in the bottom L3.
So you have connected the wiring to the light as it is?
Did you also connect at the switch?
Do you have a multi-meter and know how to use it - you might need it?
Have you tried disconnecting the conductors from the light, put each of them including the earth in their own terminal block and tried the light switch then?
You need to replace that connector. It is designed to have a cover over the front of it which is missing, and as it is now, it will allow the live screws to touch the exposed metalwork of the fitting.
It sounds like there is some damaged wiring somewhere on the installation, rather than an issue with the light or switch and associated connections.
It sounds like there is some damaged wiring somewhere on the installation, rather than an issue with the light or switch and associated connections.
Yes I just connected live-live and neutral-neutral.
The switch was never disconnected so they have always been in the state that they are in the pics.
I have a multimeter and know how to use it.
I have put each of the wires in some terminal block with the light disconnected and tried. All of the light stay on.
The switch was never disconnected so they have always been in the state that they are in the pics.
I have a multimeter and know how to use it.
I have put each of the wires in some terminal block with the light disconnected and tried. All of the light stay on.
Thanks all for your help, sounds like I might have to get the professionals in!
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