Originally Posted by sailcrazy
Based on what I've been told....do NOT use the US 220v (a 4 wire system, 110, 110, neutral, ground)) into a European 230v (a 3 wire system, 230v, nuetral, and ground) by bypassing the neutral wire in the US 220v system. By doing that you are using the ground wire for return current
and not for the safety
purpose it was/is intended for. Yes....it will work, but if there is a fault/short in the system......it's called FIRE! While the cycle difference needs to be addressed(motors-yes, resistance appliances-no, electronics-??) if the marina can not supply you with a 230v (or 240v) 3-wire supply, then you need to use a transformer to convert the 120v (3-wire) to 240v(3 wire) to use.....and keep the ground wire for safety-as it was intended.
It's reasonable to caution against using US 240v split phase into a EU 230v boat, but the condition you describe is not correct. The danger
is someone screwing up the connections to the proper wires, as when done properly, the US ground wire would not be the return path for the EU wired system, the return path is the US L1/L2 (as that's where the 240v potential lies). The ground wire would still function as a safety
wire, the difference being it would not be at neutral potential. This would only matter in EU appliances
that are expecting neutral and ground to be the same potential, and that type of appliance design has not been used for many years. If the EU appliance has the 2 prong plug
and plastic case, it implies internal shielding from the case and it wouldn't care that neutral and ground are at different potential. It's the older metal case appliances
(if anyone remembers such things) that *could* be a problem. In reality, there is more protection with this design as IF either side of the circuit, being EU L/N or US L1/L2 (whatever you PoV), touches ground, it'll blow the circuit breaker, which is the job of the ground safety wire.
So, if wired correctly AND the appliance is capable of operation on the different frequency, connecting a EU 230v to US 240v split phase works fine.