Pro power GFCI issues

[DoneWithIce]

Had my electrician wire in my Generac 6852 transfer switch along with a connected Reliance controls PB-30 Power inlet box. Had 8 circuits moved from the main panel over to the manual transfer switch/panel. Total load was approx 12-13 amps. When main service was disconnected and the truck was powered up, once a cb for one of the circuits was place on it it popped the gfci in the bed and I got a ground fault message. I know I seen some discussion of this, can anyone point me in the right direction to give my electrician some knowledge regarding proper wiring of this switch to prevent this from happening. Thanks so much.

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[Runaway Tractor]

The 6852 is a subpanel with an integrated transfer switch. That transfer switch does switch both hots and the neutral from both main and gen sources. However, if your electrician was lazy and only wired the branch circuit hots to the subpanel (leaving the branch circuit neutrals on the main panel), this is what will happen. The hot and neutral for each branch circuit needs to be moved to the sub-panel. That way the circuits on the sub-panel have no bond except that which comes from the truck (or bonded portable generator), or the main.

 

[Maquis]

If it only happens when switching on 1 of the 8 circuits (others work) there is a wiring problem on that circuit. Likely a neutral - ground connection.

If it happens with any of the 8 circuits, I agree with @Runaway Tractor . That or he didn’t bother to run the feeder neutral to the transfer switch.

 

[DoneWithIce]

Thanks guys, I appreciate the good info. This company is recommended by Qmerit one of the two in my area, but first time wiring a transfer switch that is powered by a generator or battery that incorporates a GFCI. I’ll start with bringing all the neutrals over to the transfer switch. Thanks again

 

[tls]

That sounds wrong. The Generac 6852 should switch both the neutral and hot for all circuits connected to it, meaning there is no bond for the truck's GFCI to "see" when the neutral is switched to the generator inlet.

More likely is a situation further downstream with two neutrals tied together that should not be. Happens a lot in device boxes with multiple switches or outlets on different incoming circuits, where someone gathered all the neutrals together in one wire nut for convenience.

 

[Henry Ford]

This thread will point you in the right direction.

 

[chl]

The 6852 is a subpanel with an integrated transfer switch. That transfer switch does switch both hots and the neutral from both main and gen sources. However, if your electrician was lazy and only wired the branch circuit hots to the subpanel (leaving the branch circuit neutrals on the main panel), this is what will happen. The hot and neutral for each branch circuit needs to be moved to the sub-panel. That way the circuits on the sub-panel have no bond except that which comes from the truck (or bonded portable generator), or the main.

Exactly.
All the neutrals for the circuits you are backing up need to be disconnected from the neutral bus in the main service panel and connected to the individual white neutral wires provided by the transfer switch. It is in the instructions that come with the 6852, but maybe not as clear as it should be.

I saw a couple YouTube videos where the electrician did what yours did.
With an unbonded neutral generator, it would work.

But with a bonded neutral generator, there will be two paths to ground and the GFCI will detect a difference in the current on the Hot lead and on the Neutral lead and assume there is a ground fault and open the circuit.

I have also seen electricians say to lift (not connect) the ground. Yes, that will stop a GFCI trip, BUT it is very dangerous and could result in a shock if you touch the chassis of the truck.

I drew a diagram to explain how there could/would be a path to ground through your body - something you want to avoid. I actually read a post where the owner got a shock from touching the frame and I drew this to explain why what the electrician did, lifting the ground, was bad practice.

The transfer switch, when connected properly, will disconnect the neutrals from the ground bond at the service panel and ground them to the generator/Lightning ground when using the generator/Lightning - they will remain grounded through the service panel bond when using utility power.

BTW, like when powering a sub-panel in an out building like a shed, having ground rods at both ends is good practice. There are already ground rods at your main service panel. Having a ground rod connected to the frame at the generator/Lightning as well, which is the source when in use, would be a good idea, in my opinion. As long as the neutrals are switched, there will not be a problem with GFCI tripping. Ground rods at the generator/source provide an extra degree of protection for the operator.

 

[DoneWithIce]

So I had the electrician back today to finish up the wiring of my Generac 6852 Transfer switch, when they left 10 days ago the trucks GFCI was tripping when hooked up thru the reliance controls gen inlet box into the transfer switch. Back today, I spoke to him requesting he move the neutrals of the 4 moved circuits from the main panel to the transfer switch leaving no bond with the main panel. We tried several times once hooked up to pro power but tripped when the first circuit was put on line. We tried different circuits finding that the two ganged cb"s that protect the soft start ac units air handler and outside compressor did not trip the truck when put on gen line first. No neutrals with those circuits. When reg 15 amp circuits where put on line, again the truck tripped.
The electrician's plan was to disconnect the ground from the gen inlet box, not connecting it to the transfer switch ground bus bar. This arrangement allows the truck to power the 6 moved circuits without tripping the GFCI, but it gives me major heartburn. I believe the guy did not move all the neutrals over or bonded two somewhere which is causing the trip. I am not an electrician, but I believe that a hell of a lot of wattage passing thru while having the ground disconnected and wire nutted. Gonna have talk with the owner of the company tomorrow to try to convince him that the neutrals need to be properly moved. Any thoughts would be greatly appreciated. I read all the posts I can find on the transfer switch, moving them appears the way to solve the tripping issues.
Thank you.

 

[shelnian]

This video explains why you can't just plug your Lightning into a generator outlet on your house

 

[Maquis]

So I had the electrician back today to finish up the wiring of my Generac 6852 Transfer switch, when they left 10 days ago the trucks GFCI was tripping when hooked up thru the reliance controls gen inlet box into the transfer switch. Back today, I spoke to him requesting he move the neutrals of the 4 moved circuits from the main panel to the transfer switch leaving no bond with the main panel. We tried several times once hooked up to pro power but tripped when the first circuit was put on line. We tried different circuits finding that the two ganged cb"s that protect the soft start ac units air handler and outside compressor did not trip the truck when put on gen line first. No neutrals with those circuits. When reg 15 amp circuits where put on line, again the truck tripped.
The electrician's plan was to disconnect the ground from the gen inlet box, not connecting it to the transfer switch ground bus bar. This arrangement allows the truck to power the 6 moved circuits without tripping the GFCI, but it gives me major heartburn. I believe the guy did not move all the neutrals over or bonded two somewhere which is causing the trip. I am not an electrician, but I believe that a hell of a lot of wattage passing thru while having the ground disconnected and wire nutted. Gonna have talk with the owner of the company tomorrow to try to convince him that the neutrals need to be properly moved. Any thoughts would be greatly appreciated. I read all the posts I can find on the transfer switch, moving them appears the way to solve the tripping issues.
Thank you.

He either didn’t get all of the neutrals moved correctly, or you have a pair of neutrals incorrectly connected together somewhere in your house. Turning on the 120V circuits one at a time and observing which one(s) trip(s) is the way to begin troubleshooting.

 

[Runaway Tractor]

So I had the electrician back today to finish up the wiring of my Generac 6852 Transfer switch, when they left 10 days ago the trucks GFCI was tripping when hooked up thru the reliance controls gen inlet box into the transfer switch. Back today, I spoke to him requesting he move the neutrals of the 4 moved circuits from the main panel to the transfer switch leaving no bond with the main panel. We tried several times once hooked up to pro power but tripped when the first circuit was put on line. We tried different circuits finding that the two ganged cb"s that protect the soft start ac units air handler and outside compressor did not trip the truck when put on gen line first. No neutrals with those circuits. When reg 15 amp circuits where put on line, again the truck tripped.
The electrician's plan was to disconnect the ground from the gen inlet box, not connecting it to the transfer switch ground bus bar. This arrangement allows the truck to power the 6 moved circuits without tripping the GFCI, but it gives me major heartburn. I believe the guy did not move all the neutrals over or bonded two somewhere which is causing the trip. I am not an electrician, but I believe that a hell of a lot of wattage passing thru while having the ground disconnected and wire nutted. Gonna have talk with the owner of the company tomorrow to try to convince him that the neutrals need to be properly moved. Any thoughts would be greatly appreciated. I read all the posts I can find on the transfer switch, moving them appears the way to solve the tripping issues.
Thank you.

I suggest a different electrician.

If electrician numbnuts put the branch circuit neutrals on the ground bus bar instead of the neutral bus bar (or added his own bond between both bus bars), you will keep tripping as soon as you turn on a branch circuit. Neutral current will flow on both the neutral and the ground back to the truck and cause it to trip. The reason your heat pump isn't tripping out is because it is a 240v only device with no neutral. So turning that one does not create any neutral current to piss the truck off.

 

[DoneWithIce]

Making a change is the best place to start. I checked all his work today, all neutrals associated with the 4 circuits moved to the transfer switch were properly routed to the neutral bus bar in the transfer switch. I reattached the ground from the gen inlet box to the ground bar, never a fan of lifting the ground in any application. Tomorrow I'll disconnect the circuits and see if I can isolate a neutral issue somewhere downstream in the house. Thanks for weighing in.

 

[Runaway Tractor]

If it's indeed installed as you describe, and the truck does not trip until the branch breakers are closed, then I agree there must be a "fault" downstream. I use the term fault loosely since it could even be a device plugged into an outlet. Recommend unplugged everything from all the outlets first and see if it doesn't trip. Go from there on devices.

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