On Wed, 02 Apr 2008 19:07:07 +0100, Owain
wrote:

I've forgotten what you're supplying but why don't you put in a 6 or
even 8 way consumer unit with plenty of spare space, and supply at 45A
with 10mm T&E? The additional cost now is marginal, and the spare
capacity could come in very usefuy later

Thanks; that's worth thinking about. Would 10mm^2 fit into 25mm
conduit?

I was interested in RCBOs until I saw they are about £40 each! At that
price I think it would be cheaper to buy two RCD'ed CUs and fit them
side by side in the garage: one for the external lights and sockets
and the other for the freezer so that if the RCD trips on CU1, CU2
supplies power to the freezer uninterrupted. Is this technically and
legally possible?

In the future I would like to add a motorised door to the garage.
There is no other door into the garage so if the RCD trips I will have
to wind the door by hand! Would it be better to put the RCD outside
the garage, i.e. under the stairs? Notwithstanding the freezer
problem, why can't I have the RCD inside the house, rather than inside
the garage? The advantage of that would be that the whole 6mm^2 (or
10mm^2) cable run would be protected from house to garage.