On Mon, 19 Oct 2009 13:57:51 +0100 someone who may be Jim
wrote this:-

We have a qualified electrician doing the specification and
commissioning.

Electricians come in variable forms. Some just want to stick to the
standard solutions and select cable sizes from a table. Others are
very good and happy to do calculations if you pay them enough.

Surely my "proposed circuit" could be considered as a radial with
multiple spurs? In which case it could have as many spurs as necessary
so long as the cable length limit from CU to socket wasn't exceeded.

I see from re-reading your posting that you are not proposing a
large cable leading to a ring, as I wrongly assumed.

You could use a standard 20A radial circuit, without the thick
cable, provided that the floor areas were complied with.

You could also set up an non-standard radial circuit with the thick
cable, but you would need calculations done to see that all the
cables were properly protected. It may be the case that say a 32A
protective device which protected the thick cable did not adequately
protect "normal" 2.5 mm cable. There are a number of conditions to
meet when sizing cables and protective devices.




--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000...#pt3-pb3-l1g54