Ground fault on shore power trips

[smac999]

Originally Posted by Panacea2183

Question is if the selector switch is turned to OFF how can any power flow into the boat to trip the GFI?

if the N and G wires were swapped in the dock wiring. nothing normally would be noticed. (unless you clamped the green wire in the panel) but then current can flow from the N of the dock panel into the boat ground and into the water. even with his double pole main breaker off.

if everything is wired correctly. when his double pole breaker is off. no current can flow on either the N or H and you can't blow a GFI if there is no current. there is obvisouly an issue. with a clamp meter, volt meter, and knowledge it wouldn't take long to find.

[Panacea2183]

Problem solved!
The inverter has a relay that switches the neutral wire when the inverter is switched on,
When there is no power to the inverter I.E.: no shore power, it defaults to "inverter mode" which connects ground and neutral (as it should) the problem occurs when the shore power is first connected the transfer relay is in inverter mode which immediately blows ground fault.
We isolated all the inverter load neutrals to a separate bus and no more problems.
Thanks for all the in put.

[smac999]

is your inverter before or after the main switch and breaker which you said was off?

I have seen this happen but an inverter / charger should be after these. and therefore shouldn't have happened when off.

[Panacea2183]

Originally Posted by smac999

is your inverter before or after the main switch and breaker which you said was off?

I have seen this happen but an inverter / charger should be after these. and therefore shouldn't have happened when off.

Inverter is after main but neutrals were tie together so when no power to inverter the inverter grounds the neutral as it should

[DotDun]

Originally Posted by Panacea2183

Inverter is after main but neutrals were tie together so when no power to inverter the inverter grounds the neutral as it should

This implies your main is a single pole breaker, might want to look at a double pole.

[Maine Sail]

Originally Posted by Panacea2183

Inverter is after main but neutrals were tie together so when no power to inverter the inverter grounds the neutral as it should

Inverter should only Earth the neutral when it is in operation and inverting. When passing shore power, not inverting, neutral and ground should be unbonded by the transfer switch.

[mitiempo]

Originally Posted by Panacea2183

Inverter is after main but neutrals were tie together so when no power to inverter the inverter grounds the neutral as it should

Which neutrals are tied together?

The neutral going to the inverter should not join with the neutral leaving the inverter.

[Panacea2183]

Correct!
That was the problem
Fixed now.