Dimmer switches give you the convenience of adjusting the amount of light output from your fixture. Dimmers allow you to use the same fixture for different applications. Set the dimmer at its highest level for general task lighting and turn the dimmer down to a lower setting when minimal lighting is needed. Wiring a three-way dimmer switch uses four wires and allows you the convenience of dimming the light from separate switches at opposite ends of a room.
Things You'll Need
Two-prong electrical tester
Orange wire connectors
Phillips or slotted screwdriver
Turn off the electrical power to the three-way dimmer switch by turning the dimmer circuit breaker to the “Off” position inside the main electrical service panel.
Test the circuit to confirm that the power is disconnected at the electrical switch box. Touch one prong of a two-prong electrical tester to the black wire inside the switch box and the other prong to any metal on the box. The tester should not register any wattage.
Connect one black wire from the dimmer to the black wire inside the switch box by twisting an orange wire connector onto both wires. Twist another orange wire connector to the remaining black wire on the dimmer connecting it with the white wire wrapped in black electrical tape. Repeat the connection with a red wire from the dimmer to the red wire inside the switch box and finish connecting the dimmer by twisting an orange wire connector onto the green wire from the dimmer to the bare copper wire in the switch box.
Push the wiring and the three-way dimmer into the switch box connecting it at the top and the bottom of the box with screws provided with the dimmer. Install the dimmer cover plate and turn the circuit breaker to the “On” position inside the main electrical service panel.