BigWallop wrote:

To comply with the 30mA RCD ruling, you won't be able to run a fan heater or
anything else of that nature on the final ring. In fact, one PC may be
enough to trip a 30mA RCD because of the feedback to earth from the
switching PSU. Try it, though.

Rubbish. My whole house is on a 30mA RCD. I wouldn't do it like that if
I were rewiring, but it is there and it doesn't give me nuisance trips.

Pete