"RichardS" noaccess@invalid wrote in message
. ..

"John" wrote in message
...
SWMBO wants me to change all the light switch plates and sockets in the
kitchen from White plastic to Chrome. I do not have a problem in doing
this
but would like some opinions on the following.

The earth cables in the wall boxes are all attached to the earth lug in
the
corner of the boxes. The Chrome plates all have an earth lug on them
(lights only). The earth wires are not really long enough to remove
from
their existing lugs and attach to the plate lugs. With me so far??

My question is, seeing as the wall boxes are all galvanised steel, the
plates are Chrome and the 3.5mm screws are metal, can I leave the earth
wires alone or do they *have* to be connected to the plates? My feeling
is
they can be left as incase of a fault developing there will be earth
continuity through all the metal bits touching each other. If not I
will
have to 'choccy block' some more earth wire to the earths in the boxes
first. Any opinions or advice greatly received.


Been tackled on a number of occasions in this ng.

Bottom line IIRC is that you can rely on the screw if and only if one of
the
lugs in the back box is NOT adjustable.

In any other case (and I would do this even if the above is true) then you
have to connect a conductor to the backbox and the earth terminal on the
face plate.

Just snip off sufficient length from some normal 2.5mm t&e, and strip it
of
insulation. Use that to make the connection, and the regs also require
that
this is sheathed with green and yellow insulation sheathing (you can buy
this in rolls and it's cheap enough). You also have to sheath the exposed
earth conductors from the cables.

It's all best practise anyway and even though the regs are not technically
a
legal requirement there is absolutely no reason not to follow them.

You only need to use the earth cable (CPC) (sheathed in green/yellow as
Richard said) from an appropriate cable. The 1mm earth from either 1mm or
1.5mm ^2 T&E cables will be fine to link the light switches to the earth
terminal on the back boxes. On the sockets you need only use the earth core
from 2.5mm^2 (ie1.5mm^2) to earth the chrome socket to the back box. If you
need to buy some cable to do this, buy a metre of 1.5mm^2 and use the earth
cable from this on the lights and strip the insulation off the red or back
before earth sleeving and using that for the sockets.

--
Adam