In article ,
Robert wrote:
I have a 30ma earth leakage trip that is tripping every time a
significant load (about 3KW) is applied to the "downstairs" ring main.
The immersion heater will always trip it, the dishwasher in heat mode
will usually trip it and I have seen daft things like the fridge trip
it. Note that if the dishwasher is plugged into a different circuit
but with all other appliances remaining 'as-is' the device won't trip.
This doesn't make any sense to me as the trip is seeing the same load
(and fault) regardless of which circuit is carrying the load.

It's earth leakage from the heating elements in the immersion and or
dishwasher - fairly common, I'm afraid. The fridge may have a small amount
due to RF interference suppression, and might just top up the amount
needed to trip the ELCB.

Changing to an RCCD might well cure the problem, or could you re-wire the
immersion to a non protected circuit - there's no need for it to be so
protected, IMHO.

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*Parenthetical remarks (however relevant) are (usually) unnecessary *

Dave Plowman London SW 12
RIP Acorn