Rcd tripping

[Fender]

Hi all, Got a tt system and rcd trips when all circuits are on after a couple of minuites. Only trips when the garage mcb is on with this isolated all other circuits seem ok but turn on garage and 5 minuites later rcd (which is main switch) trips and wont reset without turning all circuits off first. There are no loads on in garage except lights. Any ideas would it b garage circuit (on its own) causing problem perhaps a phase to earth fault. There is an outside halogen on the circuit but with the switch to this off in the house rcd still trips. Have not yet tried insulation test. Thanks for reading.

 

[telectrix]

water ingress in halogen light is a possible. suspecy N/E leakage somewhere in or around garage. you really have to IR test

 

[telectrix]

sorry can't edit. go logically and IR test supply cable to garage with loads disconnected. then if that's ok break it down till you find the culprit.

 

[Fender]

Hi telectrix thanks for quick reply. Would the halogen still affect garage if its swiched off?

 

[paturback]

echo tel IR test & check the lights

 

[Engineer54]

Really need to get those IR tests done, to eliminate or confirm circuits statuses. This is another of those occassions where a mA leakage clamp meter would be well worth having to hand!!

 

[telectrix]

halogen will cause tripping when off if it's a N/E fault. disconnect both L and N. then see if it still trips.

 

[Fender]

Thank you for your replies i will check it out.