I'm planning to add an extra socket to the ring main in our flat.
The exisiting socket is on one side of a solid wall in bedroom 1,
the intended location of the new socket will be on the other side
of the wall in bedroom 2. I've already replaced several sockets
so I know that the exisiting socket is definitely part of the ring
and not a spur.
As I intend to put the new socket into the ring main I am imagining
that the cables will have the following routing:
A. Exisiting mains cables enter exisiting socket 1
B. New mains cable (and earth) is added to go from existing socket 1
to new socket 2 (on other side of wall)
C. New cable (and earth) is used to connect new socket 2 back to
current ring main
My questions are:
1. What is the best way to join the cables back together - I've read about
crimping, plastic joinning blocks, insulating tape etc. The cables will be
beind/inside the brickwork so once the sockets are screwed back on
they won't be moved etc.
2. Should I drill two distinct holes though the wall for the cables
in points B and C? or is it safe to have them next to one another? - I guess
they are insulated so it's probably ok?
If the above is too complex I'll resort to disconnecting socket 1 and
connecting the exisiting wires to the new socket 2 instead. The exisiting
socket has a 70kg wardrobe in front of it so I can't get to it.
How will you do (B) above without moving the wardrobe?
If you are going to move the wardrobe, the whole thing is too complicated -
if socket 1 is on the ring, socket 2 can be fed by one cable as a spur from
socket 1 with a single cable.
(anti-spam is as easy as 1-2-3 - not)
The wardrobe will be moved by parnter and his dad. I've seen the telewest
engineer shift it whilst full of clothes so I know it can be done but it's
sort of task I wish to perform to get to the socket on a daily basis. If we
budge it then I'll empty it as it was possible to move it (empty) last year
we built it.
There is already a spur connected to the ring so I need to include the new
socket on the ring and not as a second spur.
I suspect the thinking is that a ring circuit is usually initially
installed with no spurs (or very few at most). If you start reaching
the point where you have as many spurs as original outlets, then
you should be rewiring the ring to meet your current requirements,
and not continuously extending one which obviously falls far short
of your current requirements.
Strictly, this is just a recommendation in the On-site guide.
It was removed from the wiring regs, IIRC when 16th edition first
There is no such restriction. In practice, getting 4 wires into
a connection on the back of a socket can be a challenge, but it's
not impossible given a good quality socket and a deep back box
for the extra wires.
You should avoid adding large loads near one end of a ring circuit.
In this case, take the spur from the ring circuit fuseway.
OK, but you might need to do calculations! I presumed that the
recommendation to do this was to prevent loads of spurs being taken off the
same area of a ring causing lopsidedness. If you don't follow the
recommendation, you still have to find an alternative method of not doing
I don't think this is actually in the regulations is it, it's sort of
grown up from the "no more spurs than sockets on the ring" rule. It
can be quite difficult to get four sets of wire into one socket back
box in a decent fashion though.
You can have more than one spur on a ring. You just can't have more
than one (double) socket on each spur. There is also a nominal limit
on the total number of spurs allowed, there shouldn't be more spurs
that there are sockets on the ring.
So the simple (and perfectly acceptable) solution for you is to wire
the new socket as a spur.
However if you are ever likely to want to add further sockets in the second
bedroom then overloading problems could occur.
If it is possible, then the best way to avoid this future problem is to
proceed as you originally described, but instead of trying to connect back
into the ring (step c), work out where it goes and decide if it is practical
to pull a new length of cabling through so that your new socket is cleanly
linked to the next socket in the ring.
Danger is that if you 'loose' the cable whilst pulling through then things
start to get more difficult so ensure that you take all precautions for a
good mechanical lock between the new and old cables (eg folded back and
twisted, with a dab of solder to stop it coming undone) and some tape
wrapping to ensure no sharp edges to get snagged !
No reason why cables B and C shouldn't pass through one hole on brickwork,
just ensure edges are protected or rounded to stop the sleeving from getting
Don't bother putting it on the ring properly. Run it as a spur. If the
original socket is definitely not a spur and has only two cables into it,
just run a short length of 2.5mm T&E from the existing socket to the new
I don't get this. You need access to the socket to do your original plan
too, so you'll have to either move the wardrobe, or intercept the cable
further down the wall and install a junction box (usually in the form of an
additional double socket!) or crimps.
new socket wanted -> ****
...****......................... <- ring cable
| WARDROBE | ^
+----------+ | cut cable here to insert socket
new socket wanted -> ****
WALL new cable-> . . <- old cable, rerouted
With careful planning, it isn't necessary to extend any cables, just to add
a new section between the two new sockets. You get the bonus of an
additional double socket in the original room. This looks neater than a
junction box and requires less equipment than crimps.
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