Need some ideas - RCD tripping but everything tests fine....

[Deleted member 9648]

TBH if I have these sort of problems with a single RCD install I don't waste a great deal of time if IR tests with everything connected are good. Advise to change to RCBO's. Whatever you do nuisance tripping is almost inevitable with such an install, even if you find a problem chances are something else will trip it before long and then you'll be back again for SFA because "I've already paid you once to fix it". A single RCD don't comply any more anyway!

 

[D00DY_T00DY]

Could be anything. Gremlins I bet.

Once had the moulded plug on an oven extractor being the cause of the problem once.

Eliminate the impossible whatever's left; how ever improbable must be the truth.

Better get your deer hunting cap on OP

 

[The Ghost]

Just a wild stab in the dark here. Found by changing the switch/strapping cables around on the two way lighting this cured such a problem as the earth was close to the permanent live when I swapped it to the other side of the three core + E problem disappeared. So it was two cables away so to speak, hope that is clear?

 

[Rpa07]

Just a wild stab in the dark here. Found by changing the switch/strapping cables around on the two way lighting this cured such a problem as the earth was close to the permanent live when I swapped it to the other side of the three core + E problem disappeared. So it was two cables away so to speak, hope that is clear?

Did you hear a little voice in your head to do that @Vortigern? Stab in the dark but nice result!

 

[The Ghost]

I hear the singing in the wires @Rpa07

 

[bigspark17]

Id go for accumulated leakage, if youve tested the rcd then changing it wont do anything unless you put a faulty one in. Id price for a board change 100ma TDelay main switch and all 30mA rcbo's. The current design is no good for the modern day electrics with circuit discrimination required and so many leaky electronic devices, the system needs an upgrade.

 

[weevilward]

with rcd tripping do you know what circuit it is tripping the rcd !

Hi Buzz, no I don't, it's not happening often enough to see. I've IR'd the circuits individually and the RFC sockets shows 8M so it's most likely something on this circuit.

 

[weevilward]

Wonder if the OP has an earth clamp meter? Could just be accumulated leakage!

I don't have a clamp meter but ramp testing with and without everything on shows a cumulative leakage of 4mA difference - this is effectively doing the same as a clamp meter in this case?

 

[weevilward]

Just a wild stab in the dark here. Found by changing the switch/strapping cables around on the two way lighting this cured such a problem as the earth was close to the permanent live when I swapped it to the other side of the three core + E problem disappeared. So it was two cables away so to speak, hope that is clear?

That is a niche fault, Vortigern! I'll have a look at the strappers, but I can't make it trip by operating the 2 way switching, and it has no effect on the ramp test in either position.

 

[weevilward]

Id go for accumulated leakage, if youve tested the rcd then changing it wont do anything unless you put a faulty one in. Id price for a board change 100ma TDelay main switch and all 30mA rcbo's. The current design is no good for the modern day electrics with circuit discrimination required and so many leaky electronic devices, the system needs an upgrade.

You are right Bigspark, it is a pants installation at the moment, I will recommend this but she is on a budget, so 5 RCBOs and a Type S main switch (plus labour) is most likely not going to go down well.... I'll see what she says.
So far the 'swapped' RCCB hasn't gone again, but I am not holding out great hopes!
Cheers for the advice & opinions everyone.