Inverter’s GFI Trips when battery switch goes to 1, 2 or both position.

[GordMay]

Originally Posted by Maine Sail

The key to all this is that the neutral to grounding “bond” is broken by the inverters internal or external transfer switch, when it is not actually “inverting”. This is a common problem when owners choose an inverter not ideally intended for use on a boat.
Simple test:
#1 Unplug from shore power
#2 Make sure invert function is off
#3 Test for continuity between your AC Neutral bus and AC Grounding bus

Originally Posted by Maine Sail

...The only point where they vary is that the ISO does allow an exception to the AC/DC grounding bond, if a whole boat RCD is fitted. The ABYC requires an ELCI plus the AC/DC bond.
... So in Europe ISO 13297, and the rest of the ISO standards, are law that requires the AC/DC grounding bond, (with an exception) but yet the voluntary standards of the ABYC seem to always the bad guys on this point??

Indeed. Thank you.

[boat driver]

Originally Posted by smac999

Connecting the white to ground makes the white grounded. Not hot.. that is what decides which wire is hot or not. Instead of floating. In North America.

You know every house and every dock and every marine generator also has the green and white bonded right?. As well as every marine inverter.

If you are running off shore power, on-board gen, or on-board inverter. The green and white are always connected at the source.

That is how the power system is.

If you are getting current or voltage on the green. You either have a wiring or appliance problem.

This is not correct any more and is the issue with the GFCI trips on docks-
The ground (green) and neutral (white) must kept separated until back to the master (source) panel. The boat must be treated as a sub panel if downstream of the GFCI.
The misconception is creating a boat owner and marina frustration because the electrician may not have had a clear understanding on a vessel what is the master panel.

For simplicity- the dock is a master panel when on shore power and the boat ac is a subpanel- so 3 (110 volt, 4 wires 220 vlt) wires must return to the dock or the (grounded to boat) neutral will show easier/alternative path to ground.
when the transfer switch reverts to generator- then the generator becomes the master panel.
when the transfer switch goes to invertor- the invertor becomes the master panel.

The invertor internally (on the master side of the gfci) will ground to the vessel ground.
The issue most likely based on this discussion and information will show that inside the boats ac distribution panel downstream of the gfci the neutral and grounds are combined on the neutral bus bar. The correction should be remove and combine the grounds separate- then wire the grounds directly into the transfer switch to ground terminal- this will then make the ac panel a sub panel and the transfer switch will then direct the three wires separately to the above defined power sources.

[undercutter]

You have a bad neutral back to the inverter (GFI) from the panel or a device which is wired directly to the panel. When you connect the B+ you are introducing current flow somewhere on the DC side.



Bad neutral connections will do funny stuff.


I recently had a bad neutral connection and only discovered it when I was on the hard and I grabbed hold of a handrail that is bonded to the grounding system. Quite a lift, I will tell you. The problem wasn't noticeable when I was in the water as the current had a good path to ground other than through me.

[Jarana]

Hi again,
I made the diagrams of the connection from the inverter to Ac and the proposed change since CharlieJ advised (and hes was not the only one) that ground can not be switched.
I am also attaching the AC diagram form the boat manufacturer.
I will double check again all the neutral connections.


Regards

[mitiempo]

The only error I see after a quick look is in pic 2. The galvanic isolator should be immediately after the shore power inlet, not after the inverter ground joins the incoming shorepower green wire.

Has the problem occurred since the change?

[Jarana]

Hi everybody!
I am not 100 percent sure but the reason why all this is happening is because of the monitoring system associated with the Galvanic Isolator from ProMariner that is installed. it seems that it send a "short" to test the ground and this trips the inverter's GFI continuously.

I spoke to the manufacturer and they advise to disconnect the monitor until I can replace the Galvanic isolator for a new one that does not need to be tested.

Of course, I am taking all the grounds out from the changeover so there is a permanent bond no matter if the changeover is active or not.

I will confirm that this was the mystery we were trying to resolve.

[smac999]

The active galvanic isolators will blow gfis. Yes.

You can hook the sensing wires up before the switch so it’s only on the shore cable.

The unit itself also needs to be moved to the shore ground only.

And it will be fine untill you plug into a dock gfi...


Are those units dc powered? I can’t recall. That would explain why it trips with house switched turned on. Weird.

[Maine Sail]

Originally Posted by Jarana

Hi everybody!
I am not 100 percent sure but the reason why all this is happening is because of the monitoring system associated with the Galvanic Isolator from ProMariner that is installed. it seems that it send a "short" to test the ground and this trips the inverter's GFI continuously.

Yes, that would certainly be the cause. We have had to remove those from every boat we've installed an ELCI on or on boats in marinas that are now NEC compliant and have shore based ground fault protection. Testing type GI's have long since been replaced by "Fail Safe" galvanic isolators.

[millsie]

The ac selector switch needs to be double pole

ie hot wire and neutral switched from both shore supply and inverter supply.