Hmm. I've been looking at our wiring diagram (we're using an interlocked contactor rig) and thinking about this. You certainly want the neutral between the generator and the crossover switch isolated when you're on mains power. Which means yes, run the neutral through the cross-over switch.

Whilst I'm about it, I read an article this morning where the ECA had commented on generators. A few points from that:
  • A COC has to be issued when wiring a generator into an existing installation that also has mains supply.
  • There has been one death by electrocution by a generator in Durban already. (I see the main problem being they don't have earth leakage units.)
  • The "plug generator into a plug point to power your house" is very dangerous.

I think I'm going to get my guys to point out to me anything in the SANS electrical installations code to do with generators. Murdock mentioned there was very little in a previous post. This could be interesting.