How to Convert 4-Pole Wiring to 3-Pole

Changing the Device

• 1

  Turn off the power to the circuit you are working on at the electrical distribution panel. Confirm the power is off by touching a non-contact voltage detector to the wire's insulation.

• 2

  Remove the two screws that secure the cover on the electrical box with a screwdriver. Pull out the wires and untwist the twist-on wire connectors. Pull apart the wires with your hands.

• 3

  Loosen the screw for the wire compression device in the electrical box. Pull the wires for the device from the electrical box.

• 4

  Insert the wire for the new device through the access hole in the side of the electrical box. Pull 6 to 8 inches of wire into the box and tighten the compression mechanism.

• 5

  Strip 3/8 inches of insulation off the white, black and green or bare wires with wire strippers. Loosen the grounding screw in the electrical box and wrap the green or bare wire around this screw. Tighten the screw down.

• 6

  Twist together the two black wires with pliers and install a twist-on wire connector on top. Twist together the two white wires and install a twist-on wire connector on top.

• 7

  Cut the red wire at the insulation with wire cutters. Install a twist-on wire connector on top. Push the wires neatly into the electrical box.

• 8

  Install the cover on the electrical box with the two screws used to remove it.

Adjusting the Breaker

• 9

  Turn off the power at the main breaker for the entire electrical box. Confirm the power is off by touching a non-contact voltage detector to several wires' insulation. Double-check the power is off by making sure no devices in the house have power.

• 10

  Remove the screws that secure the cover on the electrical panel. Remove the cover and set it aside.

• 11

  Turn off the breaker that serves the 240-volt circuit you are modifying. Loosen the terminal with the red wire attached. Pull the red wire out and cut it at the insulation. Install a twist-on wire connector on top. Fold the wire away from the breakers and push into the side of the panel in a way that minimizes its contact with other wires.

• 12

  Remove the metal bare wire that attaches the two breaker switch handles. This is done by pushing it out with a pointed screwdriver.

• 13

  Pry up the breaker that had the red wire attached and remove it from the panel. Install the cover back on the electrical panel.