Concession trailer

mastertech22 · Dec 19, 2023

Legends, need some advice. I am a 12v automotive electrician, but have had a side project building a concession trailer for my dad. We have an interior GE panel inside the trailer where each side, or leg, is powered by a leg of the single phase generator..... so it's essentially two panels with a shared ground and neutral, backfed from two generator plugs. Generator is unbonded and trailer is neutral bonded.

When he is at home he wants to plug into house power to backfeed power to each leg of the panel with 2 separate extension cords and home circuits.

The home gfci immediately tripped with the trailer panel neutral bonded. With the neutral bond disconnected, I can power each leg of the panel individually just fine.

My problem comes when I try to connect both plugs at the same time from the house. One or the other gfci's will trip. Can I plug into one gfci and one non gfci protected circuit safely?

Also, I have 1v on the ground side under load at the trailer panel.... I don't think this matters.

westward10 · Dec 19, 2023

With the neutral bonded it is bound to trip the gfci.
When you trying plugging it in the plugs need to be on the same gfci because of the shared neutral in the trailer.

mastertech22 · Dec 20, 2023

westward10 said:
With the neutral bonded it is bound to trip the gfci.
When you trying plugging it in the plugs need to be on the same gfci because of the shared neutral in the trailer.

Any workaround to this? My gfci circuit can't handle the amperage needed. Can I plug the other leg into a non gfci protected circuit?

westward10 · Dec 20, 2023

mastertech22 said:
Any workaround to this? My gfci circuit can't handle the amperage needed. Can I plug the other leg into a non gfci protected circuit?

It won't make any difference.

mastertech22 · Dec 20, 2023

I think I figured out what I'm going to do. On the line out of the panel going to the device I need on that leg, I am going to put a disconnect. I will tie into the appliance side another line to an outlet box, with a knife switch/light switch in between. I will then disconnect from the main panel, switch the switch to the outlet box, and connect my extension cord from my house to the box. Then hook another circuit from the home into the other side of the panel. The one appliance on the other leg will be completely isolated by the disconnect.