The three way switch has three terminals inside it instead of two. This is known as the common screw and its usually black instead of brass or silver.
3 Way Switches Explained How To Wire 3 Way Light Switch
How a 3 way light switch works. One black terminal for the common wire. A three way light switch is different than a traditional single pole light switch as it contains an extra screw to connect an extra wire. Another dead giveaway of a three way switch is the absence of on and off markings. A three way light switch allows one light to have two different light switches often in two different rooms for convenience. In this article we will solve the mystery of three way switches. It simply diverts power from one wire to the other much like a railroad might switch a train from one track to another.
Two brass terminals for traveler wires. Three way switches can be wired in a number of different ways depending on where they are located relative to the light fixture in the circuit cable runs. When both switches are connected to the same terminal then it completes the circuit and turns the light on. Here are the basics of a 3 way switch. The switch simply opens off or closes on the connection between the two terminals on the switch. If you have ever wondered how this arrangement works and how each switch knows what the other switch is doing then read on.
For example they can be arranged so that the feed cable runs to the first three way switch then to the light fixture box then to the second three way switch. The switch can connect to either terminal. Just to be clear a 3 way switch never really turns on and off. Whenever you flip either one of the switches the light changes its state if it is on it turns off and if it is off it turns on. When the switch is on current flows along the black wire through the switch to the light and then returns to ground through the white wire to complete the circuit.
Gallery of How A 3 Way Light Switch Works
