Mike wrote:

Andy - this sounds far too sensible for the IEE regs. Are you sure this is
correct as everybody else seems to think the wire is needed,

It's required in the circumstances where the earth (CPC) is supplied
_to_ the box first through metal conduit, etc. - otherwise I'll stand by
my interpretation.

including that apprentices thing on TV a few weeks back.

I saw that and it involved metalclad fittings and metal conduit. I
don't think the conduit was providing the CPC, but it and the boxes were
certainly accessible (exposed-conductive-parts) so needed to be reliably
earthed. Quite a different situation to what we're talking about here.

--
Andy