On 20 Oct, 23:24, "nightjar" cpb@insert my surname here.me.uk
wrote:
"Andy Dingley" wrote in message

There's also the issue of the workshop being near to, but separate
from, the house itself. Some "workshop" "sheds" are inbetween them
(connected to the house, if anything). One of them is a place I'd
particularly like to have robust sockets (physically and electrically)
to drive welders. What are the issues about supplying this either from
the house or the workshop incomers?

Make sure it is from one or the other, but not both, to avoid the
possibility of having some circuits live when you think the supply has been
isolated.

Is there a formal definition of "it" in the regs? The main workshop
and garage is free-standing and has the 3 phase entry through the rear
of it. There's another workshop which is "attached" to the house (via
a row of outbuildings) and that's where I'm likely to want to weld.
Now for the effort of running SWA under the concrete path, I'm happy
to power this entirely from the workshop 3 phase and can easily have
physical separation of a wall, exterior door or 6' spacing between
that and any house-fed outlets. However this would mean I'm running
two supplies into one connected "building" and I was wondering if that
was the point that "nearby" would be regarded as starting to apply.


As already mentioned, you also need to decide whether you are
going to export the earth or have a local earth.

Not sure on that either. I'm not thinking about local earths so much
as the two separate ones supplied by the 'leccy board, entering from
different directions (and quite likely, different substations). Do
these need to be deliberately bonded, deliberately isolated or what?