Inside the Three-Way Switch

Inside the Three-Way Switch

As discussed before, it is a double-throw switch. So, rather than simply interrupting the circuit, the power is diverted to a different route. The circuit goes to the common terminal and then can go through either traveler. When the switch is in the “down” position, the common is connected with the traveler on the opposite and top side (see blue line, below). When the switch is in the “up” position, the common is connected with the traveler just above the common. 

In this lesson, we will be using a brown cable that has blue, red, and white wires inside. The blue will be connected to the top left traveler, and the red will be connected to the top right. This consistency will help us keep the sides straight! 

Below is a short video showing these switches in action.