Can some one school me on how to use the by pass 120 ac volt switch on the galvanic power supply unit?
When boat is powered up with 120 shore power, & by pass switch is on, the display unit displays (no ground - fault).
Any info on how to use the system would be helpful.

When in the water you want the boat to be isolated from earth ground, otherwise many of the stay currents will be attracted to your boat. As a non-expert, the only reason I can ever see using a by-pass (which by passes the isolator) is when the boat is out of the water and plugged into shore power. Even then I probably wouldn't use it. When the by pass is switched it would remove the isolated ground and ground it to shore

Thanx for the response. Yeah I did some research last night & learned a lot about isolator systems. Today I hooked up a number of different ways. With the by pass switch on you could plug in to the shore gfi outlet & it worked with out popping the gfi all the time. But I went out later & shore power was off & gfi was tripped. So I m not sure what happened there? So now I m turning off the breaker for isolator & that seems to work @ the moment. I m still checking different scenarios when turning on power. I do not know if I agree that it does not have a Isolated ground when 120 switch is by passed & 12 volt power supply breaker is off. I do not see that as an issue because its still grounded to ground & out of the water through gfi circuit. Not a safety issue. I think i m getting gfi circuitry confused with relationship to galvanic grounding.
The way I understand this is the dock shore power Hot or neutral will open as soon as the isolated GFI circuit senses a path to dock or water for what ever cause. And or boat hot or neutral will open with same situation. Plus do the dc current protection.
Not fully understanding concept.

It wouldn't be the first time there was an issue with shore power.

What model isolator is it?
https://www.outbackmarine.com.au/dei...vanic-isolator

I talked to tech support at formula. Scott said that he has had probably 50 calls related to shore power issues. He said since marinas have been updating their power supplies they've had a lot of issues with the monitors and GFI circuits popping.

Scott is a great guy, been very helpful through the years