[Amps] Safety grounding - was Mains Isolation Transformer

[Peter Chadwick]

Lou said:
> 3 insulated wires would be #6 and the bare bond wire would be #`10.<
This is an interesting one. Is it assumed that you can't get a fault such that the full fault current flows down the ground (i.e. the protection) wire? Such fault current being greater than the normal load current? Intuitively, I'd sort of expect the protective ground conductor to be of at least the same gauge, if not bigger, than the  current carrying conductors.
Also, do we assume that in the case of two lots of 110 volt appliances, the currents will be approximately in anti phase, and so cancel  in the neutral? This would fall down with bad power factors of opposite sign. (OK - opposite sine or rather, cosine, if you want a bad pun)
73
Peter G3RZP