Mains cable behind wall
 

Hi all,

I want to add a couple of mains sockets to my ring, both next to an
existing one, so that I have three double sockets in total. The mains
cable currently comes from the ceiling and down the wall between the
plasterboard and brick. It is covered in a metal cover, obviously to
avoid anyone drilling into it etc.

My question is - from a regs perspective - as I have to extend the ring
to add these sockets, do I have to cover the cables in a similar way or
can I just run them between the brick and plasterboard with no metal
cover? (I know not to run them diagonally.)

Antony

antgel wrote:

I want to add a couple of mains sockets to my ring, both next to an
existing one, so that I have three double sockets in total. The mains
cable currently comes from the ceiling and down the wall between the
plasterboard and brick. It is covered in a metal cover, obviously to
avoid anyone drilling into it etc.

My question is - from a regs perspective - as I have to extend the ring
to add these sockets, do I have to cover the cables in a similar way or
can I just run them between the brick and plasterboard with no metal
cover? (I know not to run them diagonally.)

No need to cover (there wasn't even a need to cover the original run,
but it does offer useful protection while the place is being built).
Your new cable runs will be horizontal between visible accessories (the
sockets), which is where wall-drillers should Officially Allow For Them
To Be.

Do try to keep all your new sockets as a ring - extending two doubles
from one existing socket by daisy-chaining is a no-no, and taking two
spurs (to left and right) off one socket is permissible but hard in
practive to get all 4 conductors into the socket tunnels and into the
backbox (therefore hard to meet the 'good workmanship' requirement of
t'Regs). If you've only enough slack to reach a little further, take one
cable to the middle, rather than the end, position, leaving the shorter
one at the current edge - then run new lengths existing-edge to new-edge
and new-edge to middle, if you see what I mean.

HTH - Stefek

It certainly does. However, I have a little problem with slack. I'd
like both new sockets to be to the right of the original. This means
that of the two cables entering the existing socket, the cable on the
right will have to enter a socket quite a distance from where it is
now. I can't run it diagonally. There's no room between the
plasterboard and brick for a junction box. Is the best way of doing
this to sink a junction box into the wall above the existing socket and
run a new cable from there to the right-most one? And does it matter
that this cable will be just _above_ all three sockets, not
horizontally between them? Surely nobody would drill _there_. :-P

antgel wrote:
It certainly does. However, I have a little problem with slack. I'd
like both new sockets to be to the right of the original. This means
that of the two cables entering the existing socket, the cable on the
right will have to enter a socket quite a distance from where it is
now.

No it doesn't.

You wire one existing cable to the existing socket, from the existing
socket wire to new socket 1, then to new socket 2, then *back* to the
other existing cable, using chocolate block to connect back to the
remaining original cable.

That means that all three sockets are part of the ring, not spurs.

Owain

"antgel" wrote:

It certainly does. However, I have a little problem with slack. I'd
like both new sockets to be to the right of the original. This means
that of the two cables entering the existing socket, the cable on the
right will have to enter a socket quite a distance from where it is
now. I can't run it diagonally. There's no room between the
plasterboard and brick for a junction box. Is the best way of doing
this to sink a junction box into the wall above the existing socket and
run a new cable from there to the right-most one? And does it matter
that this cable will be just _above_ all three sockets, not
horizontally between them? Surely nobody would drill _there_. :-P

To avoid all wiring problems stack the sockets vertically (sockets are
still aligned above one another in conventional horizontal alignment)
, one existing ring cable comes into top socket, one goes into bottom
socket, new cable links top socket to middle socket and middle socket
to bottom socket. No slack problems, no wire physical protection
problems, ring remains complete, no spurs, diagonal wiring or junction
boxes, simple wiring with two cores per socket terminal, lots of space
for cables to emerge from plug tops too (surprisingly). Might look
strange but I've doubled up sockets like this for years - never done a
triple though.


--

I think what you are saying is the same as what I suggested. I never
suggested wiring them as spurs, but did suggest using a sunken junction
box, whereas you suggested chocolate block. Is there any reason to use
chocolate block over a junction box apart from the hassle of chiselling
brick to sink it in?

Is a chocolate block in a dry-lined wall regs-compliant? Seems crazt
if so as the metal terminals are "on show".

Antony

Antony

"Owain" wrote in message
...
antgel wrote:
It certainly does. However, I have a little problem with slack. I'd
like both new sockets to be to the right of the original. This means
that of the two cables entering the existing socket, the cable on the
right will have to enter a socket quite a distance from where it is
now.

No it doesn't.

You wire one existing cable to the existing socket, from the existing
socket wire to new socket 1, then to new socket 2, then *back* to the
other existing cable, using chocolate block to connect back to the
remaining original cable.

That means that all three sockets are part of the ring, not spurs.

Owain

To avoid chocolate blocks which I don't like on "heavy" loads having seen a
lot of them heat damaged, I have in the past been known to swap the old
"twin" socket box for a "double" and using two single sockets broken into
the ring and extended it that way

John wrote:
"Owain" wrote
You wire one existing cable to the existing socket, from the existing
socket wire to new socket 1, then to new socket 2, then *back* to the
other existing cable, using chocolate block to connect back to the
remaining original cable.
That means that all three sockets are part of the ring, not spurs.
To avoid chocolate blocks which I don't like on "heavy" loads having seen a
lot of them heat damaged, I have in the past been known to swap the old
"twin" socket box for a "double" and using two single sockets broken into
the ring and extended it that way

Another option would be to put a single socket and FCU onto the ring,
and wire additional sockets downstream of the FCU as a *fused* spur.

Owain