Installed Generac Transfer Switch and still getting ground fault

[sabot37]

Hoping the community can help here. I've read tons of similar forum posts but having trouble finding a code-compliant solution. Got the Generac 6852 Transfer Switch installed by my electrician, and we're still getting a ground fault as soon as we switch over to Pro Power. Has anyone run into this issue on the install and care to share what the cause & fix was?

• I know we can end this nightmare by disconnecting the ground but I want to do this the code compliant way if we can
• To test the truck outlet, we plugged Sawzall into bed via nema outlet, works fine (I have a nema extension cable that splits into 4 12v outlets)
• We shut off Main, switched off every breaker in Generac panel except for one outlet with that same Sawzall plugged in, and truck ground faults as soon as we use the same tool

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[Maquis]

You have an unintended ground to neutral connection (or Generac neutral to house panel neutral) somewhere. You did move all neutrals to the Generac that are associated with the circuits now in the Generac, correct?

 

[sabot37]

Yes we ran hot and neutral wires over. Came across this helpful thread just now, going to try order of operations and if not that, sounds like we gotta chase down a neutral touching ground somewhere...

 

[hturnerfamily]

is one of the outlet/circuits a GFCI circuit?

 

[EVpower]

I understand the Generac panel has a ground to neutral bond screw. It might be green on the neutral buss (I have not seen the panel first hand) Double check that it has been removed.

Steve

 

[Henry Ford]

Here's the answer. It's from the thread you linked to above.

I've had this exact issue. I'm going to do my best to go through the steps to identify the problem below but it's possible I miss a step since I'm going by memory, which is not good. Be safe. Don't test a hot panel. Assume it's hot until you confirm it's not. You are testing for continuity, not current. Anyway...

The problem is there's a neutral touching ground somewhere when the switch is in the Generator Power position. It's that simple. You need to figure out where that is happening.

1. Make sure you lifted the correct neutral wires from your main panel. It would be an easy mistake to make to reroute the wrong wire, especially if your panel was full, like mine was.

2. Test continuity between the neutral bus and the ground bus in the switch panel with the switch in the Generator Power position. There should be no continuity.

3. If there's continuity between the ground bus and neutral bus in the switch panel, lift individual neutral wires from the neutral bus and test continuity between the individual neutral wire and the ground bus. There should be no continuity.

4. If you identify a circuit with continuity to the ground bus you have isolated the circuit where neutral and ground are touching. Figure out exactly what outlets/lights/etc. are on that circuit and start investigating. Unplug everything on the circuit and test again. If you still can't find it start inspecting outlets, light hookups, and whatever else is hooked up to that circuit. That's how I discovered a miswired fireplace fan.

If you are brave enough to face internet scrutiny, post photos of your installation here. If there's something that's screwed up it will be identified and you can address it.

Good luck! It's frustrating but if you are methodical, thorough, and safe you'll figure it out and be happy with the switch when it's put back together.

 

[Maquis]

I understand the Generac panel has a ground to neutral bond screw. It might be green on the neutral buss (I have not seen the panel first hand) Double check that it has been removed.

Steve

Only panels labeled as “Suitable for use as service equipment” will have such bonding capability. Generac subpanels are not and do not.

 

[BhamDCam]

Here's the answer. It's from the thread you linked to above.

Just want to second this. I used this exact post to chase down the ground fault issue I was initially experiencing with my setup. This helped me think through it methodically and eventually (with patience) I found the problem circuit, and even more specifically the problem outlets causing the ground fault.

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