"Owain" wrote in message ...
Yes. You don't change the circuit arrangement when you derate a cable. You
still run a 6A lighting circuit, you just have to use cable rated at 12A in
the applicable method of mounting.

A quick glance at Table 4.7 in Whitfield's electricians guide shows that
1.0mm in wall in thermal insulation has a rating of 11A which is not big
enough, so you will have to use 1.5mm at 14A. There should be no problem
using that with most lighting fittings.

Looks like I might need a copy of this Whitfield's as well as the 'On
Site Guide' - or is there really not a lot of difference between them?