GFCI Breaker

[Bob NH]

I hooked the GFCI up with the pump ground going to the ground bar in the panel and red to load and black to load lug and coiled white to neutral bar, which left the load neutral on breaker unused the breaker worked and did not trip. The test button works and also when I pull one load wire loose either red or black it trips immediatly. Is wiring the breaker this way with neutral lug on breaker open giving me protection i am looking for, more so than a normal breaker.

It is giving you the protection of a normal breaker because if the load exceeds the breaker rating for enough time to trip on overload it will trip. It will also trip "immediately" with a high current such as would result from a short.

It will also trip on the GFCI function if a ground fault in the motor causes an unbalance between the two hot leads to the motor.

I suspect that it tripped in your system when you connected the ground lead to the "load-neutral" terminal because there is some current in the grounding system caused neutral currents associated with the utility system. Following is an explanation of why that can happen.

The power company (POCO) connects the neutral of their transformer to a ground somewhere nearby, and you and others on the same transformer also have grounding systems. Any unbalanced currents on your hot lines are trying to get back to the transformer neutral and the unbalanced currents will divide among all available paths (neutral wires and ground circuits). The wire to the motor in the aquifer is a good (low resistance) path back to the POCO neutral, so some of the current will return via that wire, causing the GFCI to trip.

There is not supposed to be any normal current on the ground wires in your system. That is why the National Electrical Code prohibits connecting the neutral to ground at any point other than at the service point (usually the main disconnect panel).