Robert,
I'm amazed at what's being sold at RV supply stores. Like the adaptor that lets you plug any old extension cord into a 30-amp receptacle. Or that 4-wire to 3-wire adaptor you mentioned... I hope none of those 120/240-wired RVs have multiwire branch circuits with common neutrals!
Yes, there is currently a distribution panel with 15 and 20 amp branch circuit breakers and a 40-amp 2-pole breaker as a backfed main (408.36(F) violation already noted). Since the supplies are only 30 amps, I assume the main was intended as a disconnect only.
My concern about matching the main breaker rating to the power cord comes from 551.45(C): "A main overcurrent protective device not exceeding the power-supply assembly rating shall be provided where more than two branch circuits are employed." ("Power-supply assembly" is CEC-speak for "power cord".) Even if the main breaker was dual 30A, I just can't see how this requirement is met when using an adaptor to power both phases from a 120V 30A cord set. If I just ignore this article and depend on the breakers at the genset and at the shore-power outlet to protect the cord, life is certainly easier.
I should probably stop worrying about it and just do what's reasonable. I don't even know who the AHJ would be for something like this, anyway.
Thanks again...
Regards,
John
