On 18 Jun 2006 01:37:17 -0700, "Terry" wrote:

I am in the process of getting a 220 boat. I am thinking that if it
takes it takes two phases to make 220 for boat wiring then I can run a
separate pair from the neutral and one phase and make that into 110 for
the boat. I can then install both 220 and 110 plugs on the vessel.
Would like to know if anybody can critique me on this as I am not 100
percent sure.

I have a boat that was originally owned by a European who lived in
Hong Kong and took it to Europe for a while. When it came to the US,
the previous owner added a 240-120 stepdown transformer and added US
110v outlets. The 120 feeds the battery charger/inverter that feeds
the 120 volt outlets. The stepdown transformer is also an isolation
transformer as there is no neutral leg on the 110 which allegedly
makes using 110 v tools safer and a GFCI unnecessary. (I still have
the GFCIs because when the 120 comes from the inverter, it forces one
leg to ground.).

You could do it as you suggested and indeed the owner just before me
disconnected the transformer and tapped between one phase and ground
for 120v. When an electrician spotted that, he told me that it would
throw unbalanced loads into the generator (240v, 60Hz) when it was
operating.

The 50 vs 60 thing only involves AC motors that might run faster than
expected. A transformer will run hotter on 50Hz than on 60HZ, so
running a 50Hz transformer on 60hz isn't a problem.

Just be sure to consider battery chargers, inverters and generators as
they make the issue more complex.