RCD tripping problems

[gavin.sibley]

Hello all,

I'm having a problem with a nuisance tripping RCD, ran an RCD test on a board and results showed that RCD was knackered, swapped this out for new and tester again failed to trip the RCD, however customer is telling me of nuisance tripping 6-7 times a day whenever they try to use an appliance.

Is there any fault in a system that could cause an RCD not too trip under test, but yet trip whenever an appliance is being used. I have done all other tests on circuit and all show reasonable results for age of installation.

Thanks,
Gavin

 

[Darkwood]

Just seen this thread ...... yes no doubt we have a poor insulation resistance and wont effect the rcd until circuit is loaded had this myself with any load plugged in trips rcd and the fault was found on a lighting feed that had been trapped ..... best way to quickly find it is if you are lucky enough to obe able to repeat the tripping yourself by using the shower or plugging in a load then do this and one by one disconnect all the other circuits in the board repeating the load test.... if it still trips with all other circuit fully disconnected then the issue is your circuit your loading.

To note! This problem can also be brought on by a circuit not on the rcd or even on another rcd or rcbo. It sounds counter-intuitive but took me 3hrs first time i came across this but only 10mins now to source offending circuit if of course you have the same problem, the last time i resolved this issue the customer had used 3 other Electrical companies who all failed to isolate the problem but experience is key here as i went in and left within half hour and fault resolved.

 

[markythesparky]

Yes that's exactly what I meant, problem is, it trips with every appliance in the house and the shower, that's why I was wondering whether there was any sort of wiring fault that could cause this problem?

Is it wired backwards. I remember a sparks wired a Crabtree on the wrong way round once and it stayed on until any appliance was turned on.