Generator pops it's GFCI when I plug the rv into it after inverter install.

Sean Steele

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I recently, five minutes ago, finished the install of my Aims Power PWRIX200012SUL. It has an internal transfer switch and is hard wired into the breaker panel to power all of the general purpose wall outlets on the RV. I am dry camping and just did a test to see how the transfer switch worked. I fired up my generator and plugged in the camper. I heard the generator take a load and then the GFCI outlet on the generator popped. I turned off the inverter and tried plugging in the camper again. This time it instantly popped the GFCI as soon as the cord was plugged in. No hesitation or change in sound, just SNAP.

Before the install, I had no issues plugging the camper into this generator. The install is pretty straight forward. The power coming from the circuit breaker in the panel goes to the AC input on the inverter and the AC output of the inverter goes back to behind the panel and completes the circuit for the outlets. The inverter is powering the outlets just fine. Since it keeps popping the GFCI, I assume there is a ground fault somewhere. The only change to the routing of the ground wires is at the inverter and in a junction box where I connected the output of the inverter to the original wires for the outlet circuit. I ran new Romex to and from the inverter. The chassis of the inverter is grounded to the chassis of the camper. The generator is not grounded to earth. The 12V system in the camper is grounded to the chassis in a different location.

Im looking for some ideas on where to look for the issue first. Do I need to earth ground the generator?
 
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Bud Martin

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Are you having Neutral bonded to safety ground at more than one point? It should be bonded at the main power source only otherwise you will have load current flowing in the safety ground wire which is a no-no and that is why the GFCI will trip, it only take about 5mA of un-balance current on the L and N to trip the GFCI.
 

Sean Steele

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IMO the first thing to suspect is a new neutral-ground bond inside the RV.
I checked for continuity between the ground rail and neutral rail in the camper's breaker box and did not get anything. I also tested at the prongs of the plug.

I should probably check to see if the inverter is a floating or bonded ground type. The connections on the AC side of the inverter have a separate connection for each wire, H, N, G.
 

Sean Steele

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Are you having Neutral bonded to safety ground at more than one point? It should be bonded at the main power source only otherwise you will have load current flowing in the safety ground wire which is a no-no and that is why the GFCI will trip, it only take about 5mA of un-balance current on the L and N to trip the GFCI.
Please see my reply to Tigerwillow. I'm not sure if this answers your question. Admittedly, when it comes to AC power, I try to just match colors. Black to black, green/copper to green/copper, white to white. Etc.
 

Bud Martin

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Can you draw up the wiring diagram of the whole setup?
Do you have the manual of the Aims Power PWRIX200012SUL? I would like to see if it has grounding relay that ties the Neutral of the AC outlet to safety ground or not.
 

Pappion

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I checked for continuity between the ground rail and neutral rail in the camper's breaker box and did not get anything. I also tested at the prongs of the plug.

I should probably check to see if the inverter is a floating or bonded ground type. The connections on the AC side of the inverter have a separate connection for each wire, H, N, G.
Manual is not specific about floating or bonded ground types. Inverters can have a bonded ground. Off or Transfer switch should disable it.
manual
 

Tecnodave

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The GFCI in the generator is tripping because there is a neutral to ground bond in the inverter. This is a real common problem. There does need for there to be a neutral to ground bond but at one place and one place only.

Here is where the problem arises....when running on batteries and inverter alone the neutral to ground bond is done in the inverter, but when you plug into external power be it shore power...(the power grid)...or a stand alone generator the neutral to ground bond is done at the source of power...the utility connection or portable generator....

Solution....a proper transfer switch which handles the neutral ground bond. A home transfer switch does not transfer the neutral ground bond as you remain connected to the power grid.....BUT.....a real marine or vehicle transfer switch does transfer the neutral ground bond. Commonly used in Ambulances and Fire Apparatuses

Modern motorhomes with the built in Onan generator do the neutral ground bond in the generator control panel but if you add a inverter to the situation you must provide that neutral ground bond with a transfer switch or transfer relay.

Some inverters have this built in, My MagnaSine has a relay which switches neutral ground bond from internal to external if wired that way so if i plug into shore power the inverter shuts down, becomes a battery charger and does the ground neutral bond switching automatically.

Running on shore power, shore connection does bonding, Running on generator, generator does bonding, Running on inverter, inverter does bonding.

That may well not be an option on an inverter only or on some less high end inverters and inverter/chargers

In any case the proper place for ground bonding is done at the source....
 
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Pappion

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amazon review:

Kennaldo

3.0 out of 5 stars Almost perfect, but with a major flaw for me.
Reviewed in the United States on May 6, 2020
Verified Purchase
I like everything about it, save for one thing. If your shore power is GFCI protected It will trip the circuit. I Called tech support and they said yup it’ll do that, it’ll trip GFCI outlets. Unfortunately most of the places I’d plug it in are GFCI. :(

8 people found this helpful

IMHO: There may be resistive ground bond to keep it from floating. Transfer switch might be single pole, only switching the hot wire.

Another amazon review:

VaVet96

2.0 out of 5 stars Not recommended for RV use
Reviewed in the United States on December 30, 2020
Verified Purchase
Wish I had read the other reviews before buying this, particularly the one by Kennaldo in May 2020. Had it professionally installed this Spring and it worked well. Late this summer, we tried to plug the coach into a garage outlet that was GFCI. First time since the install of the inverter. Tripped every time. Spent weeks trying to track the cause of the current leakage down myself as I am not a professional. Neutral/ground bonding, voltage leaks, random resistance wiring issues can be hard to isolate. Finally hired a certified electrician who quickly isolated the problem to this inverter. It is wired correctly, but something internal is causing resistance that in turn causes the leakage and the GFCI problem. Disconnecting the neutral wire on the input side eliminates the issue. Ended up having electrician install a 2 pole switch for the input side to allow me to disconnect the inverter when we encounter a GFCI power source. Can still power appliance and plugs on the output side from battery power. Ridiculous to have to do this, but it works. Disappointed.

4 people found this helpful
 

Sean Steele

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Can you draw up the wiring diagram of the whole setup?
Do you have the manual of the Aims Power PWRIX200012SUL? I would like to see if it has grounding relay that ties the Neutral of the AC outlet to safety ground or not.
Manual says, "The ground terminal has already been connected to the ground wire of the AC output receptacle through the inverter."
 

Tecnodave

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Manual says, "The ground terminal has already been connected to the ground wire of the AC output receptacle through the inverter."
Right there is the problem.......You cannot neutral ground bond at the inverter if you are plugged into an external source of power

<EDIT> I did not read your reply good enough to understand what you said....Did you say the ground wire or did you mean to say the inverter neutral ground bond wire....not the same thing at all.

The frame of the inverter does need to be connected to the ground connection of the AC outlet but the neutral wire can be bonded here or left floating. My Exectech is wired that way as well as a lot of the Zantrex and other “utility class inverters”
 
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Bud Martin

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"Manual says, "The ground terminal has already been connected to the ground wire of the AC output receptacle through the inverter."

We are talking about inverter AC outlet Neutral being tied to the Safety ground or not by the inverter, if it is then it has established second Neutral to Ground boning point which is a no-no.
Is this the manual? very poor manual.
 
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Sean Steele

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Ok. Thank you all for pointing out the issue. Here I thought I was getting something good with the automatic transfer switch built in.

Sounds like everything is working as designed, just not compatible. I'll check in the morning but I suspect that if I flip the breaker for the outlet circuit that the inverter is tied into, I won't have the issue I am experiencing. I also suspect that when plugged into regular 30 amp shore power source, everything will work as it should.

Sound correct?
 

OffGridInTheCity

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The GFCI in the generator is tripping because there is a neutral to ground bond in the inverter. This is a real common problem. There does need for there to be a neutral to ground bond but at one place and one place only.

Here is where the problem arises....when running on batteries and inverter alone the neutral to ground bond is done in the inverter, but when you plug into external power be it shore power...(the power grid)...or a stand alone generator the neutral to ground bond is done at the source of power...the utility connection or portable generator....

Solution....a proper transfer switch which handles the neutral ground bond. A home transfer switch does not transfer the neutral ground bond as you remain connected to the power grid.....BUT.....a real marine or vehicle transfer switch does transfer the neutral ground bond. Commonly used in Ambulances and Fire Apparatuses

Modern motorhomes with the built in Onan generator do the neutral ground bond in the generator control panel but if you add a inverter to the situation you must provide that neutral ground bond with a transfer switch or transfer relay.

Some inverters have this built in, My MagnaSine has a relay which switches neutral ground bond from internal to external if wired that way so if i plug into shore power the inverter shuts down, becomes a battery charger and does the ground neutral bond switching automatically.

Running on shore power, shore connection does bonding, Running on generator, generator does bonding, Running on inverter, inverter does bonding.

That may well not be an option on an inverter only or on some less high end inverters and inverter/chargers

In any case the proper place for ground bonding is done at the source....
I have an MPP Solar 3048LV in my camper and if I use a house circuit with/GFCI as shore power it will trip the GFCI after a bit (10 or 30secs) - maybe the MPP Solar takes 'a bit' to recognize shore power and when it does it trips as described above?

I have the incoming (shore power) ground wire connected to the MPP Solar input and output and the 120v distribution panel - out to the plugs in the trailer.

I'm new to camping / only used campground power once so far - and it worked but I didn't see GFCI at the breaker box.

So I just use a different circuit (non GFCI) from the house for shore power as I don't think this is particularly dangerous... but I'm still learning.

Appreciate the discussion here.
 

Sean Steele

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Right there is the problem.......You cannot neutral ground bond at the inverter if you are plugged into an external source of power
Am I reading the manual incorrectly? I read it as the inverter chassis ground lug being tied to the ground terminal of the inverter's AC output. Nothing about neutral.
 

Tecnodave

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If that is what is said in the manual that is the way to do it.

What the problem is where is the neutral bonded to ground, you can have only one place where that can happen or you will have circulating currents between the neutral and ground circuits. If the Hot wire and Neutral wire are over 3 ma. difference in current this is seen by a GFCI as a ground fault which is exactly what it is.

The GFCI cannot function if there is any connection between the neutral and ground.

Im no specialist in off shore electronics but if this unit was built for a RV it “should have” neutral ground bond options.
 

Sean Steele

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https://photos.app.goo.gl/vcRBnUvj4nTYYfC56 at one point in time, I had the back panel off of the inverter but I was focused on the DC side of it and didn't get a clear picture of the AC side. It looks like the green and white wires are isolated but I can not see the end of all of them.

I guess I will just have to work around the issue for now and save up for the Victron multiplus that I wanted in the first place.
 

Tecnodave

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Am I reading the manual incorrectly? I read it as the inverter chassis ground lug being tied to the ground terminal of the inverter's AC output. Nothing about neutral.
So do you have a volt ohmmeter, any type, digital or analog, with the inverter off, no power check the resistance between neutral and, ground then between hot and ground. If neutral to ground is zero ohms then the inverter does have internal neutral to ground bonding. Opening it up you should see the bond. If both readings are the same then its unclear.

I was writing while you posted but this is fixable simply but the Victron is a real product where I would not say that about AIMS
 

Sean Steele

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I have a multimeter, used it to check continuity between neutral and ground on the camper as stated earlier. I'll add this check to my list for tomorrow. Thank you for the help.
 

Sean Steele

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SNIP:

I was writing while you posted but this is fixable simply but the Victron is a real product where I would not say that about AIMS
When I was researching, I saw that AIMS had a good reputation in the marine industry. I don't know if they have changed hands or mfg since then but I still see mixed reviews. Never saw the neutral/ground bond issue in any research before now. I had this thing in a box for almost a year because I changed campers before installing it.
 
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