RCBO tripping

[bus-nut]

Hi There just had to go and do a quick check on a suspected RCBO tripping.

Tested the RCBO and am satisfied it is ok and working fine, customer is complaining that only the wall lights in the lounge keep blowing lamps and trip keeps going but it is only the wall lights none of the other lights on the circuit.
SO not wanting to get to involved straight off as not getting paid at this point.
I done a insulation resistance test live/neutral together and to earth 13.40M ohms
With all lamps in place sitches closed etc. so trying to explain that this is technically satisfactory. any way they are also saying that it trips of its own accord with nothing turned on. SO i went to the switch plate Feed and neutral are at the switch so from the switch i seperated the circuits and tested out to the centre light (switch wire and neutral then both to earth with lamps removed is between 11 and 13 M ohms) done the same to the wall lights (with lamps removed and just switch wire, neutral and to earth all seperate) same figure. so then tested the neutral and earth of the out going feed to the rest of the small extension same figuer and they have the same style lights fitted throughout. Could this be cheap light fittings?? any advice would be welcome.
I did also explain that using cheap lamps is also a common problem as they dont last but they argued back with that its on the wall lights that do it in that room none of the others go?

I have not gone to far into it as Im am getting over the back operation and shouldnt be working anyway and it was a free test just to try and establish if it was something simple or not.

Thanks

 

[Sparky Ninja]

Tested the RCBO and am satisfied it is ok and working fine,

Did you do a ramp test etc?

customer is complaining that only the wall lights in the lounge keep blowing lamps and trip keeps going but it is only the wall lights none of the other lights on the circuit.

OK, could be rubbish lights. Could be rubbish lamps. Could be rubbish connections. Could be one of many other things.

SO not wanting to get to involved straight off as not getting paid at this point.

You're as bad as me

I done a insulation resistance test live/neutral together and to earth 13.40M ohms
With all lamps in place sitches closed etc.

Did you do any continuity tests?

so trying to explain that this is technically satisfactory.

Good luck with that

any way they are also saying that it trips of its own accord with nothing turned on.

Doubtful There must be something pulling current for the RCBO to detect the leakage CURRENT, otherwise it could be N-E but that would most certainly always trip.

SO i went to the switch plate Feed and neutral are at the switch so from the switch i seperated the circuits and tested out to the centre light (switch wire and neutral then both to earth with lamps removed 13.40 is M ohms) done the same to the wall lights (with lamps removed and just switch wire, neutral and to earth all seperate) same figure.

Neutrals at the switch? Are these wall lights on the lighting circuit?

so then tested the neutral and earth of the out going feed to the rest of the small extension same figuer and they have the same style lights fitted throughout.

Did you then repeat the test on the supply to that point, with the outgoing side you've measured that figure on disconnected?

Could this be cheap light fittings??

Maybe, I doubt it.

any advice would be welcome.

Carry out some continuity tests first, between the conductors, then break down the circuit into different stages and obtain reading for those sections. Remove accessories and fittings if deemed necessary.

I did also explain that using cheap lamps is also a common problem as they dont last but they argued back with that its on the wall lights that do it in that room none of the others go?

Most likely that one fitting may be faulty, and may blow cheap lamps more regularly. Which may also trip RCBO. I'd rather find out more information first before saying stuff like that as it appears a little bit like guessing.

I have not gone to far into it as Im am getting over the back operation and shouldnt be working anyway and it was a free test just to try and establish if it was something simple or not.

Sounds like it's not.

 

[tenheads]

faulty rcbo???

 

[bus-nut]

bugger didnt do a ramp test, my bad!! If it carries on and when im well enough to work ill do a more thourough test for sure just wanted a bit of info to try and advise them as best as possible thats why i went in for a quick check that turned into an hour and half anyway.. I agree if it was a neutral earth fault tripping it when no power is drawn then it would have shown up on the tests and be tripping constantly. Yes they are wall lights and neutral at the switch but in a wago connect not just a choc block..

I have said to them that if it carries on let me know and ill give them some sort of price to investigate further, to be honest the woman is so vague and then she started saying the out house goes as well so i said oh so your power sockets have gone as well (because the out house is on that circuit) she said oh no its just the lights, think they were a bit confused.

 

[rocker]

Hi there, welcome to the forums!

If it's going when nothing is turned on could damp or moisture be an issue?

Are we certain we aren't having landing light borrowed neutral issues, always the first thing I check on unexplained lighting circuit problems.

I would say as well without doing a ramp test you can't really be sure about the integrity of the RCD.... you may be getting brilliant times on your RCD test, but the thing may be tripping at 1mA! I'd recommend this first if you have the facility to do it.

 

[nick611]

how do you know rcbo trips on earth fault? could be tripping as lamp blows like mcb.are lamps on their sides?if so fit low energy and problem will stop.dont look too deep

 

[buzzbar4]

Are they candle bulbs? heat dissipation comes to mind, and these are terrible for this, and will blow taking dimmers and the main main fuse with them, I have had this time and time again, change for lower wattage 30s instead of 60s check this out, if its a delayed blow could be damp.