Just to be clear a 3 way switch never really turns on and off. Two brass terminals for traveler wires.
3 Way Switch Animation How A 3 Way Switch Works
How a 3 way light switch works. When both switches are connected to the same terminal then it completes the circuit and turns the light on. If you have ever wondered how this arrangement works and how each switch knows what the other switch is doing then read on. 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. This is known as the common screw and its usually black instead of brass or silver. 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 three way switch has three terminals inside it instead of two.
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. 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. 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. Another dead giveaway of a three way switch is the absence of on and off markings. 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.
The switch simply opens off or closes on the connection between the two terminals on the switch. Here are the basics of a 3 way switch. The switch can connect to either terminal. It simply diverts power from one wire to the other much like a railroad might switch a train from one track to another. One black terminal for the common wire.
Gallery of How A 3 Way Light Switch Works
