How to Wire a 3 Way Switch

Introduction

Wiring a 3 way switch allows you to control a light fixture from two separate locations, like the top and bottom of a staircase. 3 way switches require a neutral wire to operate, but can be tricky to wire correctly. In this guide, I'll walk you step-by-step through how to wire a 3 way switch properly.

What You'll Need

Before wiring a 3 way switch, assemble the following materials:

• Two 3 way switches - You'll need a 3 way switch for each control location. Make sure the switches are the same amperage as the circuit.

• Neutral and hot wires - The neutral wire connects to the light fixture, while the hot connects to the power source.

• Two traveler wires - These will connect between the two 3 way switches, allowing them to communicate.

• Cable clamps - Used to secure the cables to the electrical boxes.

• Wire strippers - To strip insulation off the wires for connections.

• Screwdriver - To connect the wires to the switches and secure them.

Wiring Diagram

Before wiring, consult the 3 way switch wiring diagram below as a reference:

The power source and light fixture are connected to one 3 way switch, called the master, while a traveler cable runs to the second 3 way switch, called the slave.

Step-by-Step Wiring

Follow these steps to wire a 3 way switch:

1. Turn Power Off

Turn off the circuit breaker or unscrew the fuse for the circuit you'll be working on. Verify the power is off with a voltage tester. Working with live wires can result in electrocution.

2. Install the Master Switch

Mount the master 3 way switch into its electrical box. Connect the neutral wire to the neutral terminal, and the hot wire to the common terminal.

3. Connect the Traveler Wires

Connect the two traveler wires to the traveler terminals on the master switch. One traveler wire runs to the slave switch, while the other runs to the light fixture.

4. Install the Slave Switch

Mount the slave 3 way switch into its electrical box. Connect the two traveler wires to the traveler terminals.

5. Connect the Light Fixture

At the light fixture, connect the hot source to the black wire on the light. Connect the neutral wire to the white wire on the light. Connect the last traveler wire to the black wire on the light.

6. Secure Wires & Test

Secure the wires with cable clamps and wire nuts. Turn the power back on and test the switches to verify proper operation.

And that covers the basics of how to wire a 3 way switch! Let me know if you have any other questions.