What is a Three-Way Switch?

A three-way switch is a type of electrical switch that makes it possible to control a light or other electrical load from two different locations, like the top and bottom of a staircase.

To wire a three-way switch circuit, three-way switches have three terminals:

Three-way switches get the name because they have three possible positions: on, on via the other switch, and off.

How Do Three-Way Switches Work?

Three-way switches work by toggling between providing a power path between the common terminal and one of the traveler terminals.

When the light or other load needs to be turned on or off from two locations, cables called 'travelers' connect the two three-way switches. The travelers carry the switching signal between the switches.

One of the switches has an additional 'hot' wire connecting to the common terminal to provide supply power to the circuit. The other switch's common terminal connects to the load you want to control.

Flipping either three-way switch reconnects the travelers and common terminal to change the power flow in the circuit. This lets you turn the light on and off from either location.

Wiring a Three-Way Switch

Follow these steps to wire a three-way switch circuit:

1. Connect the Power Source

2. Connect the Light or Load

3. Connect the Traveler Wires Between Switches

4. Connect the Neutral and Ground Wires

5. Mount the Switches and Test the Circuit

Helpful Tips

Here are some helpful tips when wiring a three-way switch circuit:

Safety Precautions

Take these safety precautions when working on home electrical wiring:

Conclusion

The basic process to follow when wiring a three-way switch is:

  1. Connect power at one switch.
  2. Connect the load at the other switch.
  3. Install traveler wires between the same terminals on both switches.
  4. Complete neutral and ground wiring.

Key tips are labeling wires, breaking off switch tabs, and taking safety precautions.

With good wiring practices and by following code, a three-way switch circuit can provide safe and convenient control over lights and outlets from two locations.