Locate the outlet less than 200 feet from the circuit breaker box. Choose the correct wire gauge based on the current draw of the appliance to be run on the circuit. Use four-conductor wire for new installations. Two conductors are hot and have approximately 110 volts each.
220-volt appliances must be run from a double-pole circuit breaker. This device is essentially two 110-volt breakers in parallel, and one hot line is run from each breaker. Ensure that the breaker is turned off, and install the wires into it.
Cut the wire to the appropriate length, and strip approximately 2 inches of the insulating jacket. When cutting the jacket, ensure that the insulation on the conductors has not been lacerated. Strip about 1/2 inch of insulation from each of the conductors using wire strippers.
Install the junction box, and thread the wires through the box, installing strain relief clamps if necessary. Connect the wires to the appropriate terminals on the 220-volt-rated receptacle, and screw the receptacle into the junction box. Power the circuit by turning on the breaker, and test the outlet using a multimeter. The voltage across the left and right terminals must read 220 volts, while each terminal to ground must read 110 volts. The voltage between neutral and ground must read zero.