"Christian McArdle" wrote in message .net...
What I should like is to put sockets for electronics (computers,
TVs, clock radios etc) on separate circuit(s) to those used for
kit which is likely to trip RCDs.

You can. However, if your current installation is prone to tripping, then
something is wrong. You may find you have an appliance with a latent earth
fault, or a neutral/earth short somewhere.

many thanks for all replies - I see there is a parallel posting
running

OT - Fitting RCD in household mains supply

which goes into these issues in some depth.


Whilst I appreciate the benefits of appropriate fitting of RCDs, I'm
unconvinced that they are always appropriate. Safety is something
that has to be managed & you have to weigh up the pros and cons of the
different options.


Agreed, my elec installation is overdue for update - but that's how
this post started & renewal work is in slow progress. Nevertheless
what happens poses some curious Qs. eg:

1. The front of house RCD (30mA) CU CAN trip when a light bulb
blows or it can be the MCB in the lighting cct: both happen, though
perhaps the MCB trip is the more common.

2. The Hedgecutter fed off the rear fused cct (with or without an
in-line RCD socket) usually makes the front RCD trip - while the
in-line RCD stays on. ditto for the B&D sander & other m/c tools (but
less often). All these are double insulated with 2 wire cables - so
where is the earth leakage?

Some time ago I queried all this with an elec engineer who made the
helpful(?) observation that 'loops sometimes do funny things'

I'm far from convinced that there's a fault of the simple
shorting/leakage type. Seems to me more likely that the tripping is
due to

a) the L-N imbalance detected by the RCD must be something to do with
variations in power factor & not earth leakage - ie capacitances &,
perhaps, inductances in the motors & suppressors:

(b) the peculiar design of elec hand motor tools - which are not
straight forward inductance or synchronous motors - more some *******
style of ac commutator motor (I've only a very rough idea on these
things). Still leaves the mystery of why fusing light bulbs trip the
RCD (but answer may be in the parallel post).

Lastly I'm still slightly paranoid about maintaining supply the the
electronics around the house especially this computer which is on most
of te time, even if I'm out. The fitting a UPS would be 1 answer but
that is expensive & would still leave sockets (on the UPS) which are
effectively unprotected.