You need to read the relevant section of BS7671 which I don't
have to hand, and I don't remember that section off the top of
my head, but I've guessed some answers below.

"Dave" wrote in message
...
Should an earth spike be used when a generator is used to power class 1
equipment that normally needs an earth? (thinking of safety and ignoring

Yes.

EMC). I should know the answer to this but can see two sides of the coin
and can't choose between the two.
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.
.. and how would an RCD cope?
The particular case is using a gen to provide power for an outdoor PA
system (and maybe a band).

If the generator was supplying only one appliance, you could regard
it as an isolated floating supply or an IT earthing system. However,
as soon as you are driving multiple appliances (particularly something
like an outdoor PA/band), it's not isolated anymore, and you probably
need to make it a TT earthing system. In either case, the wiring regs
still apply to the whole installation.

--
Andrew Gabriel