Inverter 12V to 240 V AC How to earth?

[JOHNPEET]

The research that I undertook during my build led me to the configuration as per my previous comment - AC earth connected to the Neg Bus and a single bonding cable connecting the Neg Bus to the hull. I have a steel hull with isolated DC systems throughout. By connecting the AC earth to the Neg bus, should a fault occur resulting in 230v being present on the DC circuitry, the RCD will trip without relying on any human contact to force to do so. Thus avoiding the small risk of the RCD not operating with the required disconnection time.
Bonding the DC Neg bus to the hull in one location only, protects the hull against corrosion (galvanic?) should a DC fault occur connecting the DC pos to the hull - this will result in a final circuit fuse operating. This arrangement then allows the accessible single hull bond to be disconnected periodically, to allow a continuity test to be carried out between the Neg bus and hull to ensure that the DC circuitry remains isolated from the hull. Thus preventing current flow through the hull.

Just to complete the picture - I have an isolation transformer on the shore power supply with the incoming earth left disconnected at the transformer. For the generator - one leg of the generator winding is connected to the earth terminal at the generator thus providing a common neutral earth point