How to Connect a Three-Wire Dimmer

Wiring a three-wire dimmer is simple once you know where the wires are connected.

A dimmer switch is used to vary the brightness of a light. This is ideal for adjusting the mood of the room by controlling the light more precisely. Any single-pole switch in your home can be converted to a dimmer switch. A three-wire dimmer is used for a switch that is connected in a three-way configuration. This is where two switches are wired together to control one light. You can wire a dimmer with some common tools.

Things You'll Need

• Noncontact voltage detector
• Wire cutters
• Wire strippers
• Pliers
• Wire nut

Instructions

1. Turn off the power for the circuit you are working on at the main distribution panel. Confirm that the power is off by touching the insulated cover of the wires with a non-contact voltage detector.

2. Strip 3/8 inch of insulation off the red wire and the two black wires coming from the distribution panel at the electrical box. One of the black wires may be a white wire with a small section of black electrical tape wrapped around its cover.

3. Connect one of the black wires from the dimmer with one of the black wires coming from the distribution panel by twisting them together with pliers. Install a wire nut on top of the two wires.

4. Twist the other black wire from the dimmer with the other black wire coming from the distribution panel and install a wire nut on top.

5. Twist the red wire from the dimmer with the red wire coming out of the electrical box and install a wire nut on top. The red wire travels between the two switches in a three-way switch arrangement, which is called the common circuit.

References

• Home Depot: Installing a Dimmer Switch