How to Wire a Welder Plug

A welder can use the same electrical source as that of a clothes dryer with a three-prong plug.

Many welders use a plug wired into a 240-volt power source.Many welders use a plug wired into a 240-volt power source.
For this to work, the welder needs to wire into a plug with prongs shaped and spaced the same as the dryer. Many welders designed for residential use require a 240-volt 30-amp power source, the same as a clothes dryer. A three-pronged 240-volt receptacle contains one ground wire and two 120-volt wires phased 180 degrees from each other. To understand phase, think of one 120-volt wire as positive and the other as negative; the difference between them equals 240 volts.

Unscrew the welder plug's base from its cap with the correct type of screwdriver, usually a slotted screwdriver. Most replacement plugs use three screws, located between each prong, to hold the cap in place.

Push the welder's wire through the hole in the plug's cap. The part of the cap that tightens against the base should face the end of the wire. Some caps have wire clamps surrounding the hole. If so, loosen the wire clamp's screws with a slotted screwdriver before attempting to push the wire through.

Strip 1/2 inch from each wire with wire strippers.

Examine the welder plug's base. Wire retaining screws connect to wire terminals on the side opposite the prongs. The two side-by-side terminals connect to the 120-volt wires with silver and gold colored screws. The other terminal connects to the ground wire with a green screw.

Loosen the wire retaining screws with, depending on the plug's brand, either a Phillips-head or slotted screwdriver.

Wrap the stripped end of the green insulated wire around the green screw. Tighten the screw with the correct screwdriver.

Wrap the stripped end of the white insulated wire around the silver colored screw. Tighten the screw with the correct screwdriver.

Wrap the stripped end of the black insulated wire around the gold colored screw. Tighten the screw with the correct screwdriver.

Slide the plug's cap to its base. Align the base's screws with the cap's screw holes. Tighten the screws with the correct screwdriver.

Tighten the cap's wire clamp, if equipped, with a slotted screwdriver.

Things You Will Need

  • Screwdriver set
  • Wire strippers

About the Author

Based out of Central Florida, Robert Sylvus has been writing how-to and outdoor sports articles for various online publications since 2008. Sylvus has been a home improvement contractor since 1992. He is a certified HVAC universal technician.