On Fri, 13 May 2005 18:12:20 +0000 (UTC), Dave wrote:

Should an earth spike be used when a generator is used to power
class 1 equipment that normally needs an earth?

Yes, and bond the generator chassis to that spike and to which ever
phase from the alternator you decide to call "neutral". ie replicate
the sort of supply that the equipment is designed to be plugged into.
A protective earth wire connected to real ground via a spike, neutral
bonded to that earth at the supply source (generator).

On one side it would be good to tie the gen and neutral down to
Earth, but on the other side it would seem sensible to let the whole
lot float.

Letting the neutral float is not good. One fault and that phase
becomes as near as damn it earth potential but the other is now 240v
away from earth. If that fault is in the live side the neutral is now
sitting at 240v WRT earth. Single pole switches and/or single pole
fuses, some thing looks off but is still very much live.

... and how would an RCD cope?

An RCD doesn't care about earths or lack of. All it cares about is
that the same amount of current going to the load comes back (within a
few tens of mA). If there is a current inbalance the difference must
be going somewhere else which is probably A Bad Thing.

So put in a spike at the generator bond that to the generator chassis,
bond a phase from the alternator to the chassis and earth spike and
use an RCD.

--
Cheers
Dave. pam is missing e-mail