That's what you'd call a "GFI" or ground fault interrupter at the local hardware
store. It is comparing current
in two of the three incoming lines (nothing "outgoing per se) and what probably is happening is that the inverter
or some other piece of equipment
has the ground/neutral line hooked up incorrectly so the GFI is tripping out.
There have been some extensive discussions about this recently, either here or on the Sailnet.com forums
. (Sorry, both have pale blue backgrounds and I have no idea which it was.) But the folks at Freedom should also be quite familiar with this, if you contact them they should be able to tell you exactly what to look for, and how to fix the neutral/ground connection that is causing the problem.
A galvanic isolator
or other equipment
to isolate stray currents may also do it--if you find that recent thread you'll find the real answers in it.