Light started tripping circuit

[noidea1]

Hello

Just looking for any advice on an issue that has started occurring at my daughters house

Over the last week the downstairs lights have been tripping the circuit breaker to the point where she has had to leave it off, i went and had a look today and narrowed it down to the kitchen light, this has had an LED fitting in for 3 years or so without any issues

I took the fitting off and checked the wiring , refitted just to make sure, there are only two as this is not earthed, switched the power back on , turned on the light and it worked fine, turned off the light and it began flashing and tripped the circuit, tried again just to confirm and the same thing happened.

I swapped the LED out with a standard light , wired up and earthed and that tripped immediately the power went back on, tried again with the switch in the off position and the filament light blinked a few times and tripped the circuit

Checked the switch itself for loose wiring, this is a 3 gang , two way switch operating as one way only , one for the kitchen and two for external security lights that are wired up but no lights fitted, been that way since she moved in 5 or so years ago, no loose wiring i could see but the only thing i can think of is the switch itself is now faulty.

Would appreciate any other opinions or possible solutions as i can easily fit a new switch myself before having to call out an electrician

Thanks

 

[endecotp]

tripping the circuit breaker

What exactly is the thing that trips? MCB? RCD? RCBO?
Post a photo of the consumer unit if you’re unsure.

 

[noidea1]

Hello

Thanks for the reply

It is only the RCD for the downstairs lights that trips

There are 5 lights on this circuit plus the two external security lines mentioned

 

[ericmark]

Most likely water has got into the outside lights and you have a neutral to earth fault.

However since lights only tend to have line switched, to test needs equipment, trial and error is unlikely to find it. Insulation tester costs around £35 for cheap one, so big question is if worth buying and learning how to use safely, they normally use 500 volt, or is it better to employ an electrician?

Can also use clamp-on ammeter, with a 0.001 amp increment scale, but same problem, not cheap.

It seems likely some capacitive or induction linking as well, hence the flashing, I would disconnect outside lights first and see if that works. I mean fully disconnect both line and neutral.

 

[crystal ball]

My first thought is water, although you say there are no outside lights fitted how are the cables terminated, JB or taped up

 

[terryplumb]

Hello

Thanks for the reply

It is only the RCD for the downstairs lights that trips

There are 5 lights on this circuit plus the two external security lines mentioned

Unlikely that you have an RCD just for a lighting circuit. Show us a pic of the consumer unit and indicate what breaker trips.