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[TimLouth]

I moved house last year and replaced the fuse box with a consumer unit. The socket rings and garage, shower and cooker circuits are all protected by an RCCB.
Every now and then the RCCB trips, it has happened about 8 or 9 times now. It happens every 10 days or so, though there is no real pattern to it. None of the MCCB's trip, except once when the socket ring went with the RCCB but this may have been a coincidence.
The last time the RCCB tripped was last night between 1 and 4 in the morning.
Have I got a duff RCCB, or is there anything I can do to try and track down the snag.
Any help or advice would be gratefully recieved.
Many thanks.

[sparx]

In a lifetime in the trade I have only ever had 2 out of spec RCCB's, an rcd tester will confirm if connected with all outgoing mcb's off, or an Earth leakage clamp meter around live & neutral tails, (not including Earth ). If niether available An insulation tester 'Megger' with all accessories in house UNPLUGGED should show a low I.R. fault which is what the RCCB is seeing, good luck, Sparx