Battery Charger tripping GFCI

Mkwirsch

New Member
I just completed an upgrade to a lithium battery on my travel trailer. As part of the upgrade I abandoned the original charger that was part of the WFCO 8735 power center and replaced with a Progressive Dynamics 45 amp lithium charger. Everything worked great when I powered the new charger direct to an outlet on my house with an extension chord but when I hooked the trailer to shore power and plugged the new charger into a 20 amp GFCI protected circuit it trips at the outlet. The 20 amp breaker at the trailer panel is fine.

Is this just an issue with the sensitivity of the GFCI and the answer is to use a non-GFCI circuit? My understanding is the 45 amp charger will run on a 20 amp circuit? This is my first system so want to be sure I am not doing anything stupid.

Thanks in advance for any help.
 

FilterGuy

What, me worry?
The most common cause of unexplained tripping of CGFI on mobile systems is that there is a double Neutral-Ground bond.

What Inverter are you using?
 

Mkwirsch

New Member
The most common cause of unexplained tripping of CGFI on mobile systems is that there is a double Neutral-Ground bond.

What Inverter are you using?
I am using a Giandel 2200 watt pure sine wave invertor but its output is not tied into the AC side. I only have some basic tech needs that I just plug directly into the invertor.

Your comment has me wondering if I made a grounding mistake. The stock battery negative was grounded to the chassis so I currently have a chassis ground run from the DC negative bus bar. Not sure if this is the cause of the current tripping issue but the more I think about this the more I think this may be wrong.
 

HRTKD

Boondocker
Do you have room on the AC panel for another breaker? If so, install a new non-GFI breaker that is dedicated to the converter.
 

Mkwirsch

New Member
May be you should draw up the wiring diagram so we can easily how they are wired up together.
The following is the system. Still questioning if the DC bus should go to chassis?

The shore power to the charger is the charger plugged into an outlet on the 20 amp GFCI circuit (AC).

fyi...the charger is 45 amp (30 amp listed below is outdated). Also the DC - DC is not wired in yet so not the issue.

1614570569997.png
 

Mkwirsch

New Member
Do you have room on the AC panel for another breaker? If so, install a new non-GFI breaker that is dedicated to the converter.
That is my plan if this is just due to a sensitive GFCI outlet. Just want to be sure I have not made a mistake somewhere else.
 

Bud Martin

Photon Sorcerer
That is all for DC side, the GFCI works by detecting the imbalance of the current flow on the Holt and the Neutral wires, for example, if 1A of current is flowing from Hot to the laod and return back to the power source through Neutral wire, if the return current is the same as source current then the GFCI will not trip, but if the return current is 5mA less than the source current then teh GFCI will trip.
So we need to see the wiing of the AC power.

"The shore power to the charger is the charger plugged into an outlet on the 20 amp GFCI circuit (AC)" So are you saying the shore power outlet is GFCI outlet? I do not understand.
 

Bud Martin

Photon Sorcerer
You may also try having the device connected to the GFCI one a time and see what is the last added device causes the GFCI to trip.
But we still need to see AC wiring.
 

HRTKD

Boondocker
House breaker panel -> GFI breaker -> outlet -> RV shore power cord -> RV breaker panel -> GFI breaker -> converter

In the above circuit, there are two GFI breakers. From what I hear, that's a no-no.
 

Mkwirsch

New Member
That is all for DC side, the GFCI works by detecting the imbalance of the current flow on the Holt and the Neutral wires, for example, if 1A of current is flowing from Hot to the laod and return back to the power source through Neutral wire, if the return current is the same as source current then the GFCI will not trip, but if the return current is 5mA less than the source current then teh GFCI will trip.
So we need to see the wiing of the AC power.

"The shore power to the charger is the charger plugged into an outlet on the 20 amp GFCI circuit (AC)" So are you saying the shore power outlet is GFCI outlet? I do not understand.
I just mean that the charger is plugged into an existing 20 amp AC circuit and not hard wired.
We need a diagram of the AC side.
I do not have a AC diagram but this is a very small/basic trailer and the AC side is still factory. @HRTKD has it correct...

House Breaker Panel -> GFCI outlet - > RV shore power chord - RV breaker panel ->GFCI outlet -> next outlet/charger
 
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HRTKD

Boondocker
Easy answer: Cut off the plug on the converter, install new non-gfi breaker in the trailer's AC panel, wire converter directly into the new breaker.

Less easy answer: Install new outlet within the cabinet where the new LiFePO4 converter lives. Install new non-gfi breaker in the trailer's AC panel. Run 14/2 romex from the new breaker to the new outlet. Plug converter into new outlet. This is the solution I did for my new LiFePO4 converter. But not because of GFI. I needed two converters to potentially be active at the same time, so a new breaker was in order. Cutting off the plug of your new converter would likely void your warranty, so consider not doing that.
 

FilterGuy

What, me worry?
House Breaker Panel -> GFCI outlet - > RV shore power chord - RV breaker panel ->GFCI outlet -> next outlet/charger
So the inverter is not plugged into the RV AC at all?? (Neither Hot or Neutral)

Which GFCI breaker is popping? the one in the RV or the one at the house?


I highly recommend figuring out why the GFCI is popping. You can make the symptom go away by not using a GFCI.... but there is most likely a ground fault problem in the RV that needs to be addressed. Going to a non GFCI just masks it.
 

Bud Martin

Photon Sorcerer
So the inverter is not plugged into the RV AC at all?? (Neither Hot or Neutral)

Which GFCI breaker is popping? the one in the RV or the one at the house?


I highly recommend figuring out why the GFCI is popping. You can make the symptom go away by not using a GFCI.... but there is most likely a ground fault problem in the RV that needs to be addressed. Going to a non GFCI just masks it.
+1 better to be safe and find the root cause.
 

Mkwirsch

New Member
So the inverter is not plugged into the RV AC at all?? (Neither Hot or Neutral)

Which GFCI breaker is popping? the one in the RV or the one at the house?


I highly recommend figuring out why the GFCI is popping. You can make the symptom go away by not using a GFCI.... but there is most likely a ground fault problem in the RV that needs to be addressed. Going to a non GFCI just masks it.
Correct...invertor is not connected to AC side in any way, just trailer battery.

The GFCI outlet in the RV is the only thing tripping. If I disconnect the charger I can run other items (heat gun, etc) off this same outlet and it does not pop. The charger is the only thing causing a problem.
 

HRTKD

Boondocker
The GFCI outlet in the RV is the only thing tripping. If I disconnect the charger I can run other items (heat gun, etc) off this same outlet and it does not pop. The charger is the only thing causing a problem.

That's an interesting wrinkle. I don't know how to explain that.
 
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