Hi Andy,

Andy Wade coughed up some electrons that declared:

Tim S wrote:
John Rumm coughed up some electrons that declared:
I can't see the need for a RCD at the switchfuse position.

Me neither, but [...]

It would of course be essential if the earthing were TT. It may be
required to get 5 s disconnection time with Ze ~ 0.8 ohm, which doesn't
appear to apply in your case (and hopefully DNO's network alterations
would only reduce Ze, not increase it).

[...]
When (if) I get a reply from EDF Technical, I'll post a summary here.

You can be 100% certain, IMHO, that they will require a fuse (or cct
breaker) and not just a switch-disconnector, regardless of
discrimination (lack of) and however nonsensical it may appear from a
purely technical point of view. Demarcation of design responsibility is
the issue, see my previous comments he

Demarcation - yes that seems a good point.

http://groups.google.co.uk/group/uk....n&dmode=source
and

http://groups.google.co.uk/group/uk....n&dmode=source

Just read them - most informative, thank you.

BTW are you sure the main fuse is 100 A? TN-S suggests an older supply,
likely to have a 60 or 80 A fuse fitted, perhaps.


No, it's really 100A by all indications. There's a sticker on the cutout
that says BS1361 100A. Haven't looked at the fuse, obviously... An early
conversation with EDF on the phone, they managed to dig up the records. The
supply connection was replaced and a new head and meter fitted within the
last 10 years and they confirmed the supply was good for 100A max.

They also told me the local network was suitable for TN-S and TN-C-S
possibly explains the excellent Ze readings I'm getting?

Cheers

Tim