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Wiring a 120 Volt 20 Amp Male Plug

Phil Altshuler

Most household plugs and receptacles have a rating of 120 volts and 15 amps. They are suitable for household appliances, including televisions, lamps and computers. Equipment that requires additional power typically has a rating of 120 volts and 20 amps. Devices that require 20 amps include window air conditioners, large electric heaters, air compressors and office equipment for commercial applications. Twenty-amp plugs are available with straight prongs that push into a mating connector. They are also available with curved prongs that push in and twist-lock into a special mating connector.

Step 1

Open and separate the plug housing to reveal the terminals. The electrical cable consists of three wires. One wire should be green, one should be white and the remaining wire is usually black or red. Strip the insulation from the wires about 1/2-inch from their ends.

Step 2

Lay the cable into the slot in the plug. One of the terminals should be marked "G." This is for the green ground wire. Another terminal is marked "W." This is for the white or neutral wire. The last terminal is usually not marked. It is for the remaining colored, or hot, wire.

Step 3

Insert the ends of the stripped wires under the appropriately marked clamping nuts and tighten the screws securely. If the plug has screw terminals, wrap the wires around the appropriate screws and tighten them firmly. Make sure all of the wire strands remain under the screws as you tighten them.

Step 4

Assemble the plug with the portion you removed previously and tighten securely. Check to be certain that no wire strands are visible on the assembled plug. Turn off the power to the mating receptacle. Insert the plug into the mating connector or receptacle, turn on the power and confirm that the equipment is working.