Date   : Fri, 04 Sep 2009 01:14:04 +0100
From   : andrew.hancock@... (Andrew Hancock)
Subject: [OT] RE: Leccy @ Acorn World '09

>If it's 32A, it's probably a MCB or RCD. If it's a RCD, then that
>operates by monitoring the current on the phase, neutral and earth
>conductors. If phase<>neutral or earth>0, then it trips. You can
>get erroneous trips because of the power-on or power-off
>characteristics or certain appliances. The earth/neutral monitoring
>can be a right bugger if you're working on a final circuit with the
>circuit break switched off, if you happen to touch the earth to the
>neutral, an RCD earlier on in the circuit will trip - even though
>the final circuit is isolated.
 
I don't think it's a MCB or RCD, it's a Wylex circuit breaker, just a posh
fuse

see picture

http://andysworld.org.uk/house/images/fusebox.jpg

Andrew