Alan Dempster wrote:

Evenin' all,

Although a seasoned DIY sparkie, I would appreciate suggestions for adding
additional SWSOs (Switched Double Socket Outlets) in this scenario. This
particular install is to go behind a television, and power a chunk of AV
gear:

|| cabling (buried in plaster)
||
_______ _________ _________
| | | | | |
--------- ------------ -------------
existing new double new double

Now the cabling runs from ceiling to floor in the lounge of my 'well old'
property! The existing double socket is on a ring. I need to add two others.

IEE 16th Edition regs state that of course, you can only add one DSO (double
socket outlet) as a spur. So do I:

1) Make a joint with choc-block inside the metal box of the exising DSO,
then extend the ring to the new end socket, looping back through the middle
one to the first

or

2) Spur off the first socket using 4.0mm cable, then spur off that (so spur
cable is within spec for two double sockets)

or

3) Bugger the regs and simply add two spurs in daisy-chain format, like
you're not supposed to do!

I call the installation 'strip sockets' because the faceplate of each double
is literally within about 2mm of the next on the wall, allowing neat and
tidy connection of up to six appliances (TV, DVD, Playstation, Terrestrial
Digital (DVB) decoder, etc etc...

Of course, electrically I'd get away with 'spurring off the first spur' -
but I want to keep as close to the regs as possible. Breaking the ring and
installing 30 amp joint boxes is not an option here. Neither is running new
cabling - cables are buried in lime-plaster than is as hard as diamond!

Incidentally, I have installed 'strip sockets' to great effect in my
computer room, giving me a total of 12 sockets by way of six 13 amp doubles.
Only on that occasion, I was able to pick up both sides of the ring under
the floor, and connect one at either end, looping in and out of each new
socket with the requisite 2.5mm sq. T&E.

I'd be eager and grateful to hear suggestions from all who have experience
of doing this type of install in the past. I suppose I'm leaning towards
option (1), with a suitably earthed metal back box.

Many thanks

Alan


Best way is to extend one limb of the ring using crimps. Or a chick
block INSIDE a socket, and run a full ring to them.

Thats what I always do.