How to Install a 220v 50 Amp Outlet

Turn off the power to the cable at the appropriate circuit breaker. Use the voltmeter to ensure that power to the cable is off. Remove 4 inches of outer insulation from the cable using the utility knife. Cut off any excess packing material in the cable. There will be three or four wires in the cable. They are required to be 6-gauge or larger to accommodate a 50-amp load.

Strip off about 1/2-inch of insulation from the ends of each wire. Twist the wire strands on each wire between two fingers to prevent loose strands from contacting other terminals. Separate the outlet from its base with an appropriate screwdriver. Look for terminal markings embedded into the plastic next to each terminal.

Insert the wires into their appropriate terminals and tighten the terminals with a screwdriver. The green ground wire goes into the terminal marked "G." Insert the two black or red wires into the terminals marked "L1" and "L2" or "X" and "Y." The red and black wire locations are interchangeable.

Insert the remaining wire into the terminal marked "W," if the receptacle has a fourth terminal. This is for the white or neutral wire. The neutral wire provides 110 volts when the appliance has some function that requires the lower voltage. The voltage from the neutral wire to either hot wire will be 110 volts.

Route the cable through the recess in the receptacle and secure both halves together. Place the receptacle in the wall box and secure it with appropriate screws. Attach a cover plate over the receptacle to prevent electric shock. If the receptacle is a surface mount type, route the power cable out the back and secure the receptacle to the wall with appropriate screws. If necessary, use wall anchors to ensure a solid attachment.

Turn the power back on. Use the voltmeter to confirm that there is 220 volts between the two hot terminals, and 110 volts between each hot terminal and the neutral terminal if there is one.