On 15 July, 15:40, "Spike" wrote:
It seems that the accepted method of earthing the metal back-box when wiring
a ring main socket is to terminate the two T&E cable earth cores (suitably
sleeved Gn/Y) into the 13A socket earth terminal, and then to run a separate
earth wire from the 13A socket earth terminal back to the earth terminal on
the metal back-box.

I don't know if it is mandatory to specifically wire the earths in this way,
or not. *I have been unable to find anything conclusive on the Internet, or
in the IEE 17th Edition Wiring Regulations.

In the past I have used this alternative procedu

Sleeve the first section of the two T&E cable earth cores (Gn/Y) and take
them directly to the earth terminal on the metal back-box. *Do NOT cut the
earth cores - instead fold them back on themselves, so they enter the
back-box earth terminal doubled-over. *Now sleeve the trailing ends of the
two T&E cable earth cores (Gn/Y) and connect them into the 13A socket earth
terminal. *The T&E cable earth cores remain continuous and uncut from where
they exit the stripped T&E cable, all the way to the 13A socket earth
terminal, but they pick up the back-box earth terminal on the way.

My thoughts on this method a

* 1. * The metal back-box would always be earthed, even if someone
disconnected and removed the 13A socket.

* 2. * If the earth wires became loose and fell out of the 13A socket earth
terminal, the continuity of the earth would remain whilst the 13A socket was
screwed into place on the metal back-box.

* 3. * If the earth wires became loose and fell out of the metal back-box
earth terminal, the13A socket would still be earthed, as the earth cores are
continuous (uncut).

* 4. * This wiring *method does make the earth core wiring tidy and more
compact. *It also avoids the problem of terminating three earth cores into
one earth terminal on the 13A socket (although I accept that many 13A
sockets now have two earth terminals). *IMO, three cores into one terminal
is a recipe for a loose core.

The only downside I can see would be if the earth terminal on the metal
back-box was a bit crude and behaved more like a guillotine, cutting through
the earth cores.

Is there any reason not to wire the earth in this manner?

Any thoughts, comments, criticisms anyone?

--
Spike

I also use method 1, simply because the backbox terminal is rather
crude.