Off-the-grid Bonding

[BMacky]

Can anyone direct me to an off-the-grid Code provision for bonding at the first panel in a system where the PV generation system is in a separate structure, and feeders from the inverters terminate in a (sub) panel at the house? I'm not sure if the first panel in the residence would be considered the main panel, or if the inverter section is considered the "main" panel. I have no off-grid experience, and was looking at a panel where all grounds and neutrals were on the same bussing. The GFCIs in the residence were constantly randomly tripping. Since separating the grounds onto a new ground bar in the first panel, no GFCIs have been tripping as before. Looking forward to replies. Thank you!

 

[petersonra]

I am not real sure that off the grid applications are covered by the code.

 

[jaggedben]

Off grid applications are absolutely covered by the code as long as they are installed on a premises and not portable.

The typical code provisions also apply.

Presumably, the PV generation system has the neutral bonded to ground at the structure where it is installed. In this case, the feeder that is run to the house should be installed with an EGC and the panel at the house should have had grounds and neutrals separated like in any subpanel. I'm not quite sure why separating them should affect GFCIs but broadly speaking it's not too surprising. It's possible from what youve said that the neutral isn't properly bonded and by separating neutrals and grounds you've masked a deeper and potentially more dangerous problem. In any case, I'd wager that the GFCI issues would be the same if the house were connected to a regular utility service which was grounded and bonded (or not) the same way.