How to Install a 3 Pole 4 Wire Outlet for a Dryer

Run a length of 10-gauge, 3-conductor electrical cable between the service panel and the location of the dryer. Turn off the main breaker in the panel and feed one end of the cable through the side or the bottom. You may be able to feed it through an existing hole that has other cables. If not, punch out a new knock-out with a screw driver and hammer and install a cable clamp. Feed the cable through the clamp, giving yourself enough slack to make connections, then tighten the screw to hold it.

Strip the plastic sheathing off the end of the cable with a knife and separate the wires. Expose 1/2 inch on the end of the white one with a wire stripper, find a vacant slot in the neutral bus, and insert the end in the slot. Tighten the lug with a screwdriver. Install the ground cable, which is bare, into a vacant slot on the ground bus in the same way.

Expose the ends of the black and red wires and feed the end on the black one into one of the circuit breakers of a double-gang, 30-amp set. Feed the red wire into the other breaker and tighten the lugs to hold the wires. Snap the double-gang breaker into a slot on the panel large enough to hold two breakers, then label the breakers on the panel door. Turn off the breakers, then tun on the main breaker.

Install an electrical box at the dryer location by screwing it to a stud with 1 1/4-inch wood screws. If the wall is covered, you may have to cut a hole with a drywall saw and repair it after you install the receptacle.

Feed the cable through the clamp on the back of the electrical box and tighten the clamp to hold it. Prepare the end of the cable by removing 6 inches of sheathing, separating the wires and stripping 1/2 inch of insulation from the ends of the black, red and white ones with a wire stripper. Crimp ring lugs onto the ends of all four wires with a pair of pliers.

Remove the two brass screws on the back of a NEMA-14P receptacle, insert one through each of the lugs on the black and red wires and tighten the screws back onto the receptacle. The hot terminals are interchangeable, so it doesn't matter to which terminal you attach either wire.

Remove the silver screw, feed it through the lug on the white wire and tighten the screw back onto the receptacle. Attach the bare wire to the green screw in the same way.

Push the receptacle flush against the electrical box, bending the wires if necessary to get them to fit inside, then screw it to the box with the machine screws that came with the receptacle. Screw a cover plate onto the receptacle, then turn on the 30-amp breakers in the panel to energize it.