Circuit Breaker Tripping (Galvanic Isolator)

[Intifada]

Hooking up my new (to me) boat to shore power and plugging things in resulted in it tripping the circuit breaker, usually on the boat's main AC board but sometimes at the shore pedestal (see attached pics).. I think I've ruled out a DC leak from batteries on board (it still trips with all batteries disconnected). I've also tested the Galvanic Isolator and the results are within range: 1.284v and 1.266v

But, with the Galvanic Isolator completely disconnected I can plug in appliances without it tripping. There doesn't seem to be an self-test function on it which, from my understanding could cause the tripping.

I've reached my limit of where Internet research has brought me and not sure what to do next, although it seems to be working the Galvanic Isolator seems to be at least part of the problem. Any ideas of what I should do next?

P.S. Sometimes it would take multiple minutes with just a phone charger plugged in to trip, sometimes I'd have to add an extra appliance to make it trip and sometimes it would trip immediately something was plugged in.

[YANDINA]

You probably have the neutral and the ground connected together in the breaker box. First thing to do is remove that.

[smac999]

when you test with the galvanic isolator out, are you connecting the 2 green cables back together to reconnect the boats ground? or leaving them off, so you no longer have a ground.

I'm guessing the later. try with them connected back. if it trips again then it's not the isolator, it's just the fact that you disconnected the ground to the dock