I am in process of having a 7KW 220 volt steam generator installed. I had a licensed electrician install a 40 amp GFI circuit using #8 4-wire (red, black, white, and copper) to location according to local code. However, the machine's wiring diagram only calls for two hot wires (black and red) a ground wire.

Will the GFI circuit still operate properly if we connect both the common (white) wire and ground wire to same connection? (My electrician says the machine will work, but doesn't know if this will defeat the GFI.)

Thanks.

Do not allow the neutral and ground to get connected together. The neutral just needs to be capped, the equipment ground needs to connect to the frame of the unit and the equipment ground bar in the panel, not the GFI.

This will leave the neutral of the GFI breaker unused, which is fine, the GFI will still detect a ground fault on either of the hots, should one occur.