On Fri, 24 Nov 2006 21:43:55 -0500, "mortond"
wrote:

Hi,

Sorry, I guess I wasn't as clear as I thought!

The marina only has a 50 amp receptacle.
I wanted to avoid the cost of buying a second 30 amp or a single 50 amp
isolation transformer.
Basically, I wnted to hook-up the convection oven and fridge to the 50 amp
shore power receptacle, like an extension cord, except, the extension cord
would be routed via a 30amp breaker on the boat (revised that from a 50
amp) to one leg of the 'Y' branch of the shore power cord.
The appliance grounds would not be connected to the boat at all. I assume
the shore power ground would be isolated from the boat by the existing
isolation transformer on one leg of the "Y" and because there is no boat
connection on the other "Y" leg.

Thanks for the interest.

David

David
Either do it right - 1 or 2 isolation transformers, or do it wrong as
above.
Any system design must consider how it handles any fault condition not
just the run-time conditions. The above scenario is a no-no. Just
sketch your circuit, think about what wires are ground referenced and
apply some faults. (Shorts to hull etc).
Tip. - The hull going live or people dying should force a rethink!

Richard

Nb "Pound Eater" Parkend G+S