This is known as the common screw and its usually black instead of brass or silver. If you have ever wondered how this arrangement works and how each switch knows what the other switch is doing then read on.
Wiring 3 Way Insteon Switches Home Automation Guru
What is a three way switch. 3 way switches are used to control lights with two switches. It is important to understand how these are wired before attempting to troubleshoot or replace. This page describes how to use 3 way and 4 way switches to control lights. 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. Most of us take for granted the ability to turn a light fixture on or off from the bottom or top of the stairs or from two different entrances to a room.
3 way switch wire diagram power to light switch in this diagram the incoming hot wire attaches to the first switchs common dark colored terminal. But a wall switch that allows this bit of magic is not a standard switch. For more than two switches one or more 4 way switches are added. There are no onoff markings on the switch toggle. There are two clear giveaways that identify a switch as being a three way type. A three way wall switch is a common type of light switch that makes it possible to control a ceiling light or other electrical fixture from two different locations in a room.
How 3 way and 4 way switch circuits work controlling a light with two or more switches. These switches do not have an onoff position like single pole switches. It is called a 3 way switch and it is wired quite differently from standardor single poleswitches. The fixtures hot wire connects. Such markings are not needed with this type of switch as they are. The diagrams below show the conventional wiring for 3 way switches.
In this article we will solve the mystery of three way switches. In a hallway or large room for example installing three way switches at both ends lets you turn the light fixture on or off from both locations. The two hot wires of three wire cable connect to a pair of brass colored traveler terminals on each switch. Controlling a light with three or more switches. There are three screw terminals on the body of the switch in addition to the green grounding.

















:max_bytes(150000):strip_icc()/Three-waySwitchDiagramNew400-56a27f6a3df78cf77276b609.jpg)