"Owain" wrote in message news:1070983973.25912.2@lotis...
"the yorkshire dalesman" wrote
| Is it permissible to have 13A sockets on 2 different ring,
| (or a ring and a radial) circuits serving the same area
| of the house?

I think it is a rather sensible idea actually;

many thanks for advice, Owain (& Christian) - part 1 of Q answered
100% - yes areas served by different ring may overlap, assuming single
phase supply.

as for part 2: your responses open a can of worms I fear:

first, in passing:
That is because there is the possibility they may be used for outdoor
equipment. Sockets which 'may' be used to power outdoor stuff MUST be RCD
protected.

that's what I understood, but if they are labelled 'indoor use by
computer/hifi/Tv only' & the sockets are a different colour (eg
yellow/blue/red) is that enough to make them 'not likely to be used
outside?




now you're ahead of me Orwain:

The best thing to do would be to install dedicated circuits for your outdoor
and workshop sockets which do not run through the same RCD as your house
sockets but have their own RCD protection.

If you have a split load CU, you could take a supply using a spare circuit
on the non-RCD side to individual RCD-protected sockets or a new RCD for
that circuit only.

The current set up is the front of house (including kitchen & HW) is
on a CU RCD: the rear (2 rooms & a workshop is on a fused CU (some
rewireable, some cartridge). Both connect into a single master
switch. (Don't ask why - reasons lost in the mists of time). Plan is
put it all on a sound footing asap, hence this post.

I've lost (open) files several times by running the computer off the
RCD circuit (eg Excel can corrupt files it has open if the switch is
thrown). Since moving it onto the fused ring there's never been any
trouble.

Both circuits test completely Ok for insulation & earth - neutral
short. Nuisance tripping comes mainly when certain tools (all double
insulated - so no earth) are run off the rear fused ring - only the
tools keep going but the front CU is the one that trips. Observation
suggests overload is the cause - an extra thick hedge twig or heavy
pressure on the hand sander.

So what's happening? & will Christian's solution of an RCBO for each
cct cure it?




If you have a whole-house RCD, this should really be replaced as it is
unsafe (a fault in your workshop could leave you without lights and with a
power tool spinning down).

Yes, It's not just the computer & the nuisance value of resetting
clocks. Having an RCD in the workshop perturbs me - a nuisance trip
could leave me in the dark with a powerful rotary saw still spinning.
So why is an RCD needed/recommended/required in a workshop? As for
distance from the supply source, most of the house is far further away
than the remotest cranny in my workshop.