On Wed, 15 Feb 2006 17:25:13 -0000 someone who may be "Andy Pandy"
wrote this:-
It doesn't go through an insulated wall (it's an internal wall).
It was just an illustration. You will need to consider the rating of
the cable when it has thermal insulation on one side.
It looks like the cooker cable and a few light cables go in at the bottom. The cooker
is almost directly above the CU so the cable won't go very far till it branches out
of the conduit.
Unless it is somewhat less than a metre you will need to consider
the grouping factor, assuming that the cooker cable feeds an
electric cooker.
I guess (as per fig 5.15 in the link below), this means that bonding the metal cases
of appliances like the washing machine and the dishwasher is not required.
It is not required. Where equipment is connected by short cables
this is enough.
I would imagine the wiring was done correctly for the extension, but the conversion
of the en suite and installation of the showers was a separate project.
Quite possibly.
The fact that
two electric showers are installed when the supply fuse is only 60A and the meter is
only 40A does not inspire confidence.
That depends on the assessed maximum demand and diversity, but it is
certainly not ideal. Do you have an overhead line or cable supplying
the house?
Is bonding the copper pipe just as it enters the shower sufficient, or should the
bonding be attached to the actual shower metalwork/earth terminal?
That depends:-)
With bonding one needs to understand what is required and what is
not. People not understanding come up with horrors from time to
time; such as metal window frames, radiators and the metal in a sink
strainer all being bonded with little green and yellow wires that
will soon be broken off. Fortunately such things are pointless
anyway.
If pipes are made out of metal and there is reliable metal to metal
contact between pipes and fittings then little is gained by bonding.
The pipes and fittings are more conductive than any bonding cable
one will see in a house anyway.
One reason for supplementary bonding is to ensure that things people
are liable to be in contact with are at the same potential. Taps are
turned off with wet hands, lowering the insulation resistance of dry
hands. People touch towel rails with wet hands to get a towel. If
the metalwork of a shower was to become live then it is a good idea
if the bath is at the same potential.
--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54