On 27/05/2018 13:07, Roger Hayter wrote:
I brief thought experiment involving connecting a generator frame and
neutral output to an earthing stake (about 100ohm if lucky) and then
opening the main service isolating switch to the house and connecting
the house electrics to the generator leads to the possibility, with an
external neutral fault in the supply system, the generator live being up
to 750 peak wrt real earth. Is this a danger that should be prevented,
and if so, how? It would seem to involve isolating the house
protective earth from the utility supply while the generator was
connected?


If you have an external neutral loss on a PME them you have also lost
the earth.

--
Adam