Originally Posted by Mike Canter
GFI breakers do NOT trip because of high current flow. The trip because of an imbalance or a leak to ground. This is why you still have a breaker in the circuit. GFI stands for Ground Fault Interupt
Mike is 100% correct. The GFI breaker is tripped when the current on the neutral is different than the current on the hot lead. It has nothing to do with circuit overload.
If current is leaking to ground there will be less current on the neutral than measured on the hot wire. The imbalance can be very slight to trip that breaker.
Suggest you get a kill-a-watt meter and plug it into your power plug to see current draw as you power systems up. I recorded what each appliance, converter etc draws.