Three Way Light Switch Wiring

When wiring a 3 way switch first screw the terminal screws of the new switch until they are difficult to turn.

Three way light switch wiring. Connect the ground wire to the green screw. Hook the curled end of the wire under the screw then tighten down the screw to hold the wire firmly in place. The black line wire connects to the common terminal of the first 3 way switch. Typical 3 way switch wiring nm cable in the 1st diagram below a 2 wire nm cable supplies power from the panel to the first switch box.

Connect the wire marked common to the black or dark colored screw. In this diagram the incoming hot wire attaches to the first switch s common dark colored terminal. Installing the switches and light 1 attach the black power cable from the wall to the general screw black in the three way light switch. The two hot wires of three wire cable connect to a pair of brass colored traveler terminals on each switch.

A 3 wire nm connects the traveler terminals of the first and second 3 way switch together. This 3 way switch wiring diagram shows how to wire the switches and the light when the power is coming to the light switch.