But a wall switch that allows this bit of magic is not a standard switch. This page describes how to use 3 way and 4 way switches to control lights.
Figure 5 34 Single Pole Switch Circuit
What is a three way switch. 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. Another dead giveaway of a three way switch is the absence of on and off markings. The two hot wires of three wire cable connect to a pair of brass colored traveler terminals on each switch. It is important to understand how these are wired before attempting to troubleshoot or replace. If you have ever wondered how this arrangement works and how each switch knows what the other switch is doing then read on. Controlling a light with three or more switches.
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. There are two clear giveaways that identify a switch as being a three way type. In this article we will solve the mystery of three way switches. How 3 way and 4 way switch circuits work controlling a light with two or more switches. 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. 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.
Such markings are not needed with this type of switch as they are. 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. The diagrams below show the conventional wiring for 3 way switches. For more than two switches one or more 4 way switches are added. There are three screw terminals on the body of the switch in addition to the green grounding. These switches do not have an onoff position like single pole switches.
3 way switches are used to control lights with two switches. It is called a 3 way switch and it is wired quite differently from standardor single poleswitches. The fixtures hot wire connects. This is known as the common screw and its usually black instead of brass or silver. There are no onoff markings on the switch toggle.