I am installing an electric line for a washer/dryer. I have a 4 prong plug (30Amps)and a 3 line (plus ground) 10 Gauge wire. I am installing a 30 Amp breaker. I have a red, black, white and ground wire coming into the circuit breaker box. My box has to large screws on the top of the box on either side of the grounding bar, one screw has existing red wires screwed into it and the other has existing white wires screwed into it. (The ground bar has the existing ground wires screwed inot it.) My question is do I connect the red and black wire to the two screws on the 30 Amp breaker and the white and ground to the ground bar?