Re: NewAir Model G73 heater. There is no wiring diagram in the owner's manual. Manual instructs use of 2 conductor cable with ground wire (I'm using 10-2 w/ground). I am wiring the 2 supply wires into a 30 amp double pole breaker. Question, should the third wire (green) be wired into the ground bar or the common bar in the circuit breaker box?