Should I bond ground and neutral in this unusual case?

[jar349]

I am installing an offgrid solar system that is not attached to the utility grid - except that the offgrid system's ground electrode conductor is connected to my house's ground electrode conductor via a bonding jumper.

Obviously, my house's main service panel has ground and neutral bonded there and nowhere else. However, as I am wiring up my offgrid equipment, I bonded ground and neutral in the offgrid system's main service panel (that is, the panel that is backfed by a circuit breaker fed by a standalone inverter and has the breakers for the AC loads).

Realizing that my offgrid system is now sharing a ground electrode conductor with my house's and that my house's ground electrode conductor is bonded to neutral in the house's main service panel... I am confused as to whether the offgrid system's main panel should also have its ground and neutral bonded.

But if you tell me that I should NOT bond my offgrid system's ground and neutral, then how will my offgrid system's circuit breakers open/trip in the event of a ground fault in my offgrid equipment?

And if you tell me that I SHOULD bond my offgrid system's ground and neutral, is it possible that a ground fault in my offgrid system could harm circuits and equipment connected to my house's utility-connected system (or vice-versa)?

 

[Dennis Alwon]

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