This one minute animated tutorial is my clearest presentation of 3 and 4 way switches in action. These 3 way occupancy sensor switches may replace the existing 3 way switches.

Oak Grigsby 4 Way 2 Pole Lever Switch Instructions Stewmac Com
4 way switch vs 3 way switch. You use 4 way switches in situations where you want to control a light or other fixture from more than two locations. Install a 4 way occupancy sensor to replace the existing 4 way switch. For more than two switches one or more 4 way switches are added between the 3 way switches. 4 way switches an animation. I am upgrading a lot of light switches in my home to z wave smart switches. A 4 way switch is used when you need 3 or more switched to control the same fixture.
A 3 way switch has three screws plus the green grounding screw. One 3 way switch must have the circuit power supply ungrounded conductor aka hot attached to its common screw and the at the other end of the switch circuit another 3 way switch must have the switched fixture feed ungrounded conductor aka hot attached to its common screw. A 4 way switch has two positions. They do not have an onoff position like single pole switches. A 4 way switch has four screws plus the green grounding screw. I will show how to wire 3 switches however you can add as many 4 way switches to the circuit as you need or want.
When doing so i need to k. For 4 way switch wiring you will need two 3 way switches one at each end and then as many 4 way switches as you want in between. How 3 way and 4 way switch circuits work. W ith any 4 way switch circuit a 3 way switch must start and end it you may have as many 4 way switches between 3 way switch 1st and 3 way switch last. Four way switches accomplish the same thing as if someone ran to one of the three way switches and flipped it. The sensing pattern should be adjusted as wide as possible and the time delay should be adjusted to provide enough time to travel the full distance of the stairway.
4 way switch configurations are used to control lights with three or more switches. A four way switch has the effect of reconnecting the two wires running between two thee way switches. The three way switch is a variation of the standard single pole switch which controls a light only from one location. This is a basic explanation of how to turn lights on and off from more than one location. Multiple on off locations. How is a 4 way switch different from a 3 way switch.
In the first position the contacts are connected straight through so that the switch has no effect. A third type is the four way switch which is used in conjunction with two three way switches to control lighting from more than two locations. A 3 way switch is used on each end with one or more 4 way switches in between the two 3 way switches. It is easy when it is a simple switch but a 3 way 4 way or n way switch circuit is trickier.