Generac 6853 trips truck GFCI

[Hardlanding]

had the Generac 6853 installed by an electrician

When I use the little rocker switch on the front of the transfer switch to change to generator mode (when truck's Pro Power Onboard is powering the 240 outlet and the truck is connected to the house), the truck GFCI trips.

However, if instead of using the rocket switch on the outside of the transfer switch, we use the insulated yellow lever that came with the Generac to manually move to generator mode, the truck is happy and the GFCI doesnt trip

Electrician trying to get help from Generac support but no insight from them yet

Ideas?

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[RickLightning]

Have you watched the truck's display to see if it surges over 30amps?

 

[Hardlanding]

I will try that

thanks

 

[Hardlanding]

come to think of it, the GFCI tripped even with all the transfer switch circuits turned off, so presumably not an excessive current issue?

 

[The Weatherman]

It may be related to the bonded ground issue that has been discussed here for the past two years. Wonder if the switch throw is bypassing the ground?”

 

[MountainAlive]

It may be related to the bonded ground issue that has been discussed here for the past two years. Wonder if the switch throw is bypassing the ground?”

Yeah it sounds like maybe it wasn’t wired for a “bonded neutral” generator, which I’ve read is what the Lightning is. Probably an easy fix for the electrician.

 

[Hardlanding]

the 6853 explicitly claims to work with bonded neutral generators like the truck, and the electrician claims to have wired it as per the installation manual

it has to be something related to that rocker switch cuz the GFCI doesnt trip when I physically switch to generator mode using the insulated lever

 

[carys98]

I’ve seen that too. I suspect it is an induced current in the ground from the magnetic field in the solenoid. The truck is extremely sensitive to ground currents. When it’s happened I just reset the breaker in the truck and it works fine. If resetting it doesn’t fix it then you have a bonded neutral problem. It’s easy to get the wrong neutral in a crowded breaker panel so if that‘s the case then you need to get the electrician back.

 

[Hardlanding]

that worked

Embarassed I didnt of resetting the GFCI while everything was still hooked up

thanks all for the help

 

[chl]

I had the same problem - I thought it might be because I had a load breaker on the GENERAC in the ON position and maybe it was the load current when switching, but it was a small load and the GFCI should not pop just because you turn something on.

The first time it happened, it was my fault - I discover one neutral was mis-wired - I grabbed one from the wrong circuit, a circuit that was on utility power so there was 120V between the Neutral and Ground pins on the input box to the GENERAC when in standby (generator) mode, which I found when I was checking continuity, it popped the light bulb in the tester, lol.

But it happened again even after I fixed that mistake when using the rocker switch.

I can use the rocker switch with my gasoline generator without popping that generator's breaker even with the full load. I used a bonding plug (connects the neutral to the equipment ground) in the gasoline generator to test it with a bonded generator.

Bonded generators (like the Lightning) are supposed to be earth grounded "near the generator" per code and also the GENERAC manual mentions that. I didn't ground the gasoline generator with a ground rod since I was just doing a test, but its breaker did not pop.

I haven't put it a ground rod for the Lightning yet to accomplish that, but I wonder if you had the truck earth grounded, maybe the truck is more sensitive to not having a nearby ground - if you didn't ground your truck nearby, maybe that is the problem?

The GENERAC should be a break before make switch so the neutral(s) should not be grounded even for an instant when switching from utility to standby (generator).

Anyway, at least we have a work around by just resetting the truck GFCI.
I don't want to have to use the yellow rod to switch the GENERAC every time.

If GENERAC has any input let us know.

 

[chl]

I’ve seen that too. I suspect it is an induced current in the ground from the magnetic field in the solenoid. The truck is extremely sensitive to ground currents. When it’s happened I just reset the breaker in the truck and it works fine. If resetting it doesn’t fix it then you have a bonded neutral problem. It’s easy to get the wrong neutral in a crowded breaker panel so if that‘s the case then you need to get the electrician back.

Yes, I grabbed a wrong neutral when wiring my GENERAC - I had 120V at the neutral wrt ground on the input box pins, OMG, which clued me in that that was the problem.

I wonder if grounding the Lightning body "near the generator" as the code says would solve the issue if it is an induced current. I didn't put in a ground rod for the Lightning before testing it. But my gasoline generator also has a GFCI and it didn't pop when testing in bonded mode without a ground rod.

Like you said, maybe the truck GFCI is more sensitive.

 

[chl]

It may be related to the bonded ground issue that has been discussed here for the past two years. Wonder if the switch throw is bypassing the ground?”

The switch SHOULD be break-before-make.

The truck neutral should never be connected to the utility (bonded and grounded) neutral, so that shouldn't be happening.

But I wondered that myself.

 

[chl]

Have you watched the truck's display to see if it surges over 30amps?

The truck tells me it is a ground fault - is there a message that says overcurrent?

I wondered if it was a sudden spike in current, but then I tried the rocker switch with no loads ON in the GENERAC and the same thing happened - GFCI pop "ground fault" message.

I would have to se up a video camera to see what happens to the draw when throwing the switch since the truck is in the driveway and the switch is in my basement. But there should be no currrent draw with no load breakers on.

 

[chl]

UPDATE: SOLVED! I used the rocker switch and got no ground fault from Lightning when the GENERAC breaker in the main service panel is OFF.

Before I pressed the rocker switch to transfer to the Lightning, I turned off the 50A breaker in the main service panel that feeds utility power to the GENERAC transfer switch and it did not pop the Lightning GFCI when the transfer was made with the rocker switch.

Perhaps there is a momentary connecting of the utility neutral and the lightning neutral AND when switching if the GENERAC service panel breaker is closed there is a small moment of load current when the two bonded neutrals are connected.

Should not be this way, but that seems to be what happens.

[EDIT: Note I wrote HOTS when I should have written neutrals now corrected]

 

[chl]

FURTHER UPDATE:

After running on the Lightning for a while I turned the service panel 50A breaker for the GENERAC feed back on - did not trip the Lightning, but...

With the 50A GENERAC feed breaker ON, when I used the rocker switch to switch back to utility, the Lightning reported a ground fault.

So now I am wondering if the solenoid switch is a make-before-break switch?

That would make for a smoother transition from utility to standby generator and back, but it will trip the GFCI in the Lightning.

I haven't tried manually switching with the yellow rod between utility and Lightning when the 50A GENERAC feed breaker is on and the Lightning is connected.

If that trips the Lightning breaker then the answer is it is a make-before-break switch.

I'll try that another day - I closed everything back up and need to do other things today.

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