How to Wire a 3 Way Switch

Regardless of what 3-way switch wiring diagram, you’re following, you’ll need to use a 3-wire cable to connect the two 3-way light switches. So what you should see if you have correct 3-wire electrical cable (Romex) is a black (power) white (neutral) and now a 3rd (Red) wire.

3 Way Light Switch Diagrams

This 3 Way Light Switch Diagram shows connections when the power comes into the first switch, on to the second switch and then on to two or more lights switched by the 3-way circuit. image via lightwiring.co.uk

3

3-Way Switch wiring diagram depicting all wires in the ceiling junction Box. In the above 3-way switch wiring diagram at each switch the black wire gets connected to the copper or black screw. In the ceiling light fixture electrical box, one black wire from a 3-way switch gets connected to the black LOAD wire on the light fixture.

3

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. The black (line) wire connects to the common terminal of the first 3-way switch. A 3-wire NM connects the traveler terminals of the first and second 3-way switch together. Traveler wires are interchangeable on each switch.

3 Way Switch Wiring Diagrams

From the dimmer, 3-wire cable runs to the other switch and 2-wire cable runs to the light fixture. The source hot wire is spliced to the common on the dimmer and the neutral is splice through to the light fixture. At the 3 way switch, the white cable wire is marked black and connected to the common terminal.

3

In this light switch wiring diagram the power feed joins the circuit via the light fixture where a two wire cable (C2) runs from the light, to the first 3-way switch (SW1), and a 3 wire cable (C3) joins the two switches. The hot source is spliced to the white wire (which should be marked as being hot with black tap) and run through to the common terminal of SW1, and from here the hot from the light is spliced through to the common terminal of the second 3-way switch (SW2).

3 Way and 4 Way Wiring Diagrams with Multiple Lights

Wiring 2 Lights and 3 Way Switches. This diagram illustrates another multiple light circuit controlled by 3 way switches. Here the source and the fixtures come before the switches. As with the other diagrams on this page, more lights can be added by duplicating the wiring arrangement between the fixtures.

How To Wire a 3

Figure B: 3-Way Switch Wire Diagram — Power to Light Switch In this diagram, the incoming hot wire attaches to the first switch's common dark-colored terminal. The two hot wires of three-wire cable connect to a pair of brass-colored traveler terminals on each switch. The fixture's hot wire connects ...