What’s the difference between a two-way switch and a three-way switch?

Light switches are just light switches, right? You flick it or click it or turn it and the light comes on, and maybe a fan spins to life. It seems a pretty simple concept.

But if you are designing a new space, or upgrading an older electrical system, you might find yourself answering questions and deciding between a two-way or a three-way switch.

Here is what you need to know.

What does a two-way switch do?

Chances are, when you think of a light switch, the one you are thinking of is a typical two-way switch. It has two positions. In one position, the light is on. In the other, the light is off.

Two positions? A two-way switch.

This is the kind of switch you have in many rooms. There is one place to turn the light on or off. In essence, when you turn the light on, you are completing a circuit, so the electricity is flowing to the light. When you turn it off, you have interrupted the flow.

What does a three-way switch do?

Much like the two-way switch, a three-way switch turns a light on or off. However, there is a crucial difference. The three-way switch is used in conjunction with another three-way switch. Each one of them has the power to interrupt the electrical flow and turn the light off from a different part of the room.

In order to be able to turn a light on or off from different points in the same room, BOTH switches must be three-way switches. That gives both of them the chance to interrupt the flow, or re-start the flow of electricity.

Three-way switches are connected to a hot wire from the electric panel and a wire that connects to the light. However, they have two special wires that connect to each other, called travellers.

These two wires create their own internal circuit so that if a light is off, either switch can turn it on. If the light is on, either switch can turn it off.

These kinds of switches are most commonly used in hallways or large rooms where there are more than one way to enter.

Confused about which types of switches you need for your electrical project? The experts at Price Electric have been solving these problems for homeowners and builders for decades. Don’t guess, hire an expert.

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