The real problem, that no one has yet mentioned, is inrush charge current.
If the transformer is sized correctly for maximum shore load, the initial
inrush will most certainly pop the breaker at most marinas. The solution I
use works very well, if anyone is interested.

Tie in series with the primary coil of the transformer a standard light bulb
socket. Insert a 100 watt light bulb of the appropriate voltage and connect
a switch capable of handling the maximum current of the transformer in
parallel across the lamp socket. In use, open the switch and connect the
transformer to shore power, then close the switch before applying secondary
load. Initially the bulb will light and then fade out. Anytime after that
bright phase, it is safe to throw the switch shorting out the lamp.
Steve


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