How to Use a 110 Extension Cord for a 220

You can easily convert an extension cord from 110 volts to 220 volts.
Modify 110-volt extension cords for use with 220-volt equipment.Modify 110-volt extension cords for use with 220-volt equipment.
The wires inside any medium- to heavy-duty extension cord are insulated to handle voltages up to 600 volts. As long as you don't exceed the ampacity of the wires by forcing them to carry too much current, the extension cord modification is safe and easy to do. Make sure you purchase plugs and receptacles that fit your equipment and existing 220-volt outlet.

Step 1

Cut off both ends of the extension cord with the wire cutter. Disassemble the 250-volt plug by removing the two screws that hold it together. Determine how much sheathing on the extension cord to remove and cut it off with the wire stripper. Only remove as much sheathing as necessary. The sheathing should fit into the plug's strain relief and end just before the wires attach to the terminals.

Step 2

Strip 5/8 inches of insulation from the ends of all three wires and gently twist the strands on each wire. Loosen the three terminals with a screwdriver. Insert the stripped wire ends into the plug through the strain relief.

Step 3

Wrap the green ground wire around the ground terminal clockwise. Tighten the ground terminal firmly. Ensure no loose strands of wire are free to move around inside the plug.

Step 4

Wrap the remaining two wires clockwise around the two terminals. The order does not matter. Tighten the terminal screws firmly.

Step 5

Reassemble the plug with the two screws. Tighten the strain relief to securely hold the cord in place, but not so tight that it crushes the cord. Repeat all these steps at the opposite end of the cord with the receptacle.

Things You Will Need

  • Wire cutter
  • Screwdrivers
  • Stranded wire stripper
  • 250-volt cord plug
  • 250-volt cord receptacle

Tips

  • Modifying the cord is the best solution. You could also make two adapter cords following this same procedure. Make one adapter with a 110-volt plug on one end and a 250-volt receptacle on the other end, and another adapter with a 110-volt receptacle and a 250-volt plug. Plug the 110-volt extension cord into both adapters and it will work the same way.
  • Only use medium- to heavy-duty cords with 14, 12 or 10 gauge wires that include a ground wire.

Warnings

  • Ensure the wire ampacity will handle the equipment you are operating. Use a 10 gauge cord for 30 amp equipment, a 12 gauge cord for 20 amp equipment, and a 14 gauge cord for 15 amp equipment.
  • If the cord gets very warm while you are using it, the wire ampacity is too low and you should use a cord with larger wires -- step up from 14 gauge to 12 gauge, or 12 gauge to 10 gauge.

About the Author

Michael Logan is a writer, editor and web page designer. His professional background includes electrical, computer and test engineering, real estate investment, network engineering and management, programming and remodeling company owner. Logan has been writing professionally since he was first published in "Test & Measurement World" in 1989.