RCD tripping issue (again) - Earth Leakage?

[Milleniumaire]

Instant tripping won’t de detected by an Earth leakage test ……,

It doesn't always trip instantly, sometimes it takes a while, sometimes turning on something else in the house e.g. the garage lights, causes the trip.

The randomness of the tripping seems to indicate it is an earth leakage issue.

 

[Murdochcat]

You need continuity , then IR tests

Nothing else will help you

 

[ericmark]

putting 500V through the house wiring is not something I would want to do as I'm almost sure I will damage something and then I'm in a worse situation!

As said there is a 250 volt range.

If not tripping all the time, then clamp-on may help, but I went all RCBO, seemed a better option, as my consumer unit I need to go outside and down steps to get to.

 

[333rocky333]

"You’ve probably inadvertently connected lighting L-E or something similar"

Definitely not. I've checked this. On some of the SWA the earth is Grey and on other the earth is the usual yellow/green, so I'm 100% sure I didn't connect the wrong wires. Besides, the 2 new light fittings I originally added, which seemed to start this issue, have been removed. Even after removing some of the other circuits e.g. unplugging the festoon lights (C6) and/or disconnecting the wall lights (C5), the remaining lights will work but will eventually cause a trip, either after a length of time, or when a light etc. connected to the same RCD is turned on. I say "after a length of time", but it is possible someone switched something on!

you sure grey is the earth, convention these days is black earth and grey neutral however in the early days either way was often used
edit just see pics and some are different

 

[CountryFan]

There doesn't appear to be any pattern as to what causes the RCD to trip, except that the garden lights are on.

Have you checked for moisture ingress? Those wires that are loose in J3 - any connected to earth/cpc?