Hi,
Since yesterday afternoon, my RCD has been intermittently tripping. It did it just now, and all I have on are my laptop, printer, external hard drive and the fridge, nothing else in the entire house is on. I've been isolating circuits one or two at a time, and when it tripped just now, the upstairs lights and sockets were off on the board. I've recently (3 months) had a new fuseboard fitted and inspected as I'm about to rent out my house. The house was re-wired 4 years ago.
Is anyone able to shed any light on what the problem could be? my best guess is faulty fuse board, theres no way it can be an overload.

Mark, April 2010

An RCD controls all the circuits - it compares the curent between live and neutral and if there's a difference of (usually) 30mA then it trips out as a safety precaution - the assumption being that the "missing" current is passing through a person and may be electrocuting them.

From what you say it may be the fridge motor cutting in and out from time to time - I don't know fridge electrics well enough to hazard a guess beyond this - some motors have a motor start/run capacitor. Capacitors don't always last as long as you would wish - but not sure if fridge motors have caps...

RCDs often have an overload trip rating of 60+ Amps - your trip is more likely to be earth leakage than overload.

Good luck...

Peccavi, April 2010