On Monday 01 April 2013 12:56 Roger Mills wrote in uk.d-i-y:

I have a dual 13A socket under my kitchen sink - powering the dishwasher
and waste disposal device. I need power for an additional appliance and
would prefer to install an additional socket rather than use a 2-way
adapter.

The current socket has 3 x 2.5mm T&E cables connected to it - which I
assume to be two for the ring main plus a spur. The cables all disappear
behind the cabinets (I didn't install them!) and there's no easy way of
knowing which is the spur - other than separating the 3 and finding out
what doesn't then work, etc.

That might be worth doing - at least when you do the wiring - just to verify
it is sane.

If there were only two, it would be easy to wire the new socket into the
ring by diverting one of the two to it and then having another short
cable between the two sockets.

If I randomly pick one of the three to divert, I may well achieve the
same thing. But I may instead end up with two daisy-chained spurs. [This
probably wouldn't matter in practice, even though it's not in accordance
with the regs].

However, if I could get FOUR wires into the existing socket, I would
have a ring plus two separate spurs - which would presumably be ok? I
wouldn't then need to worry about which one is the spur.

Is this likely to be possible? Any other relevant comments (ignoring
Part P, of course!)?

It would not be compliant - either with the regs or (I believe) with the
terminal capacity of a standard accessory.

The correct way to do this would be to try to cut out a new flush box next
to the existing socket *around* one of the ring cables (not the spur).

Then incorporate into the ring.

If your additional appliance is not power hungry, and given one load is tiny
and the other is heavy but very intermittent (dishwasher - only heavy for
the short time the heater runs) could you use one of the triple faceplates
over the old double backbox?

I would not like to have 2 or 3 heavy power users in those, but for your
scenario it seems reasonable - and better than an adaptor. But not as good
as a new socket.

Cheers,

Tim

--
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