DIY portable power with EG4 48V 100ah battery and EG4 3kW Off-Grid Inverter | 3000EHV-48

[Dennawayne]

I’ve got a little problem the GFI in my Airstream tripping only when I plug in my portable power station up to the trailer. The GFI does not trip when hooked up to shore power nor when I am on house batteries only. In the trailer I have a Victron MultiPlus 12V/3000W/ 120amp providing the pass through. My portable cart has an EG4 LL 48V 100ah battery coupled to an EG4 6000 EHV off grid inverter. When I connect the portable to the trailer it trips the GFI, not immediately but only after the MultiPlus starts chattering and making some strange clicking sounds for at least 30 seconds then trips.

The portable works fine producing 120ac that can any 15 amp load I hook it up to.

This is annoying because I’m relying on my portable station to act like a 30amp pedastal to charge my house batteries. Could it be that the MultiPlus is not accepting the inverted power from the 6000 EHV and consequently tripping the GFI? I’m stumped!

 

[sunshine_eggo]

I’ve got a little problem the GFI in my Airstream tripping only when I plug in my portable power station up to the trailer. The GFI does not trip when hooked up to shore power nor when I am on house batteries only. In the trailer I have a Victron MultiPlus 12V/3000W/ 120amp providing the pass through. My portable cart has an EG4 LL 48V 100ah battery coupled to an EG4 6000 EHV off grid inverter. When I connect the portable to the trailer it trips the GFI, not immediately but only after the MultiPlus starts chattering and making some strange clicking sounds for at least 30 seconds then trips.

The portable works fine producing 120ac that can any 15 amp load I hook it up to.

This is annoying because I’m relying on my portable station to act like a 30amp pedastal to charge my house batteries. Could it be that the MultiPlus is not accepting the inverted power from the 6000 EHV and consequently tripping the GFI? I’m stumped!

The most common reason for GFI tripping is the presence of two N-G bonds.

Your 6000EHV is limited to 3000W/120V leg, so if you're pulling more than 3000W in charging and loads, shit will happen.

Do you have the MP properly configured to only draw the correct amount of current from the portable?

 

[Dennawayne]

I’ve set the MP to allow14.5 amps.
When I did make the connection to the portable there were no loads in the trailer.

 

[sunshine_eggo]

Input unit can handle 15A sustained?

Did you try disabling UPS mode?

PowerAssist enabled?

 

[Dennawayne]

Input unit can handle 15A sustained? Did you try disabling UPS mode? PowerAssist enabled?

 

[Dennawayne]

UPS is disabled and PowerAssist is enabled. I originally disabled the UPS because my generator power wasn’t acceptable to the MP

Can the input handle 15A sustained?

The trailer has a 3000 watt inverter. The portable puts out 120V and I’ve limited the input amperage to 15 amps at the MP.

Are we talking about the portable with 6000EHV and an EG4 48V 100ah battery, I’m not sure if it can sustain 15A but it should for more than a few minutes.

Thanks, I’m still stumped.

 

[sunshine_eggo]

UPS is disabled and PowerAssist is enabled. I originally disabled the UPS because my generator power wasn’t acceptable to the MP

Can the input handle 15A sustained? The trailer has a 3000 watt inverter. The portable puts out 120V and I’ve limited the input amperage to 15 amps at the MP.

Are we talking about the portable with 6000EHV and an EG4 48V 100ah battery, I’m not sure if it can sustain 15A but it should for more than a few minutes.

With powerassist enabled, you can go as low as 7.5A on the AC input current limit. I would try that simply to establish if it exhibits the same behavior.

 

[Dennawayne]

Tried 7.5V still trips

 

[sunshine_eggo]

Tried 7.5V still trips

Yet the MP performs fine on grid-based shore power?

 

[Dennawayne]

Yes but after I tried 7.5vV I reset to 15A and went back to shore power. It only trips the GFI when connected to my portable unit.
Ground?
The hand truck ground is not connected or bonded to the trailer. I did jumper grounds between the cart and trailer but to no avail either.

 

[sunshine_eggo]

Yes but after I tried 7.5vV I reset to 15A and went back to shore power. It only trips the GFI when connected to my portable unit.
Ground?
The hand truck ground is not connected or bonded to the trailer. I did jumper grounds between the cart and trailer but to no avail either.

The noise you describe the MP as making is very concerning, so I was exploring that one.

The main cause of GFI tripping is multiple N-G bonds. Have you tried disabling the N-G bond in the EG4? You will have floating ground and a potentially hot skin, but it's worth trying as long as you're careful.

Have you altered the default behavior of the MP ground relay?

 

[Dennawayne]

I will check in the AM, thanks for the help.

 

[Dennawayne]

Just want to make sure I understand, you want me to disconnect any grounds I’ve made to both the inverter and battery on the cart then reconnect to the trailer. True?

 

[Dennawayne]

To the question of whether I altered the ground fault relay in the MP, No.

 

[sunshine_eggo]

Just want to make sure I understand, you want me to disconnect any grounds I’ve made to both the inverter and battery on the cart then reconnect to the trailer. True?

I want you to disable the N-G bond in the EG4 with the cart completely isolated from the trailer with the exception of the L1, N and G wires to the shore power connection.

 

[Dennawayne]

Some good news. I disconnected the ground from the grounding lug on the inverter.

The battery and the inverter were not bonded.

I connected the 30A RV plug back to the trailer from the inverter.

Set the MP to accept 7.5A.

The MP chatter cleared up just a familiar hum.

The GFI has not tripped yet. I say yet because when I bumped the MP up to 9.5A it tripped but it didn’t trip for a few minutes unlike before when there was MP chatter as well.

I’m including a few pictures the tester in the duplex would show good circuit with only the middle led lit. But I’m suspicious because the top led flickers but very very dimly.

I show in one photo the chassis ground disconnected.

Can I call you? I’m at 360-607-167

 

[Dennawayne]

Well….it took at least 40 minute but it dip finally trip. It’s certainly an improvement but it still tripped after all.

Should I bond the grounds of the battery and the inverter?

So I blew it I said my Klein tester RT210 showed a correct circuit when in actuality was indicating an open ground. A correct circuit would have two yellows lit and no ed lit. My mistake. The tester shows normal when I’m connected to my house by way of an extension but shows open ground when connected to my hand truck portable

 

[sunshine_eggo]

Well….it took at least 40 minute but it dip finally trip. It’s certainly an improvement but it still tripped after all.

I probably should have asked earlier, but where is this GFI circuit? Is it powering something in the trailer, or is it involved in the delivery of the power to the multiplus?

Should I bond the grounds of the battery and the inverter?

The trailer DC and AC systems should be grounded to the chassis.

So I blew it I said my Klein tester RT210 showed a correct circuit when in actuality was indicating an open ground. A correct circuit would have two yellows lit and no ed lit. My mistake. The tester shows normal when I’m connected to my house by way of an extension but shows open ground when connected to my hand truck portable

With the N-G bond of the portable broken, that's the correct reading.

Again, GFCI typically trip because of multiple N-G bonds. This creates a path where current can return over the ground wire. GFCI typically trip at some very very low detected current on the ground, IIRC, it's 5mA. Some GFCI adhere to a different standard and allow something like 10 or 20mA.

When connected to your house power, the only N-G bond is at the house.

When the MP is inverting, it supplies the N-G bond in its ground relay. When passing through, it releases its ground relay and assumes the incoming AC has the N-G bond.

I can't really provide any guidance, and the issue appears to be tied to the portable.

 

[robbob2112]

Link explains GFCI and how it works -- requires a ground - a N-G bond (only 1), and your L1

Post in thread 'Yet another grounding question - Off grid only double shipping container setup panels on roof'

Dec 17, 2024

The fix in that thread was he didn't have an EGC from his main panel to the container and the panels were not bonded to the EGC. He attached the EGC to all the electrical boxes, the container shell and to the panel frames and the problem was solved.

Seems like he also had a metal box with 240 in it and one of the wires was crosses up so it was 240 between the ground pin and L1, while it was 120 between L1 and L2 ... I am not sure on this detail other than he had multiple things going on. If he had the EGC connected it would have popped the breaker and lead to the discovery of the...

• robbob2112

As @sunshine_eggo has said several times - it sounds like your N-G bond is screwy - there can be only one.

When you are in the airstream do you also have a generator hooked up when you are off-grid? If so there is very likely a N-G bond inside that and if the inverter also does a N-G bond it would cause the GFCI to trip. This may be in place even when a generator is not running.

You should absolutly have the ground wire from the portable tied to the ground on the trailer -

 

[sunshine_eggo]

As @sunshine_eggo has said several times - it sounds like your N-G bond is screwy - there can be only one.

I should have posted this earlier: