Caution: To prevent severe shock or electrocution always turn the power OFF at the service panel before working with wiring.
Never Assume the power is off! Always double check, and test the device before you begin work.
A four-way switch is used with two three-way switches to get three switch points. Before wiring the four-way switch make sure to check which terminals make a closed connection when the switch is flipped. In our illustration below the connection is made across the switch terminals. Some four-way switches may make the connection vertically across the terminals.
Make sure to check the instructions, or use an electrical meter to make sure how the switch you are using is making it's connection.
Notes about the above electrical diagram.
The switch in the center is a four-way switch, the other two switches are three-way switches. You can tell by the number of terminals on each one.
Typically a 14/2 or a 12/2 cable is used as a feed, a 14/3 or a 12/3 is ran in between the switches. Than a 14/2 or 12/2 is ran to the lighting fixture. The use of either 14g or 12g cable is determined by the current load of the lighting fixtures you are controlling.
Two Types of four-way switches.
1) Make sure all devices and splices are in a UL listed electrical box of the proper size
2) Make sure you attach the ground wire to all metal boxes and all devices, with the proper ground screw.
3) Twist wires together with pliers, before you put the wire nut on. Double check to insure that the connection is tight, and that no copper is showing.
4) Always use the screws for termination of wires. Never use the holes in the back of a device for the connection.
5) Switches have different ratings, some switches may be rated for 15amps at 125 volts, while others will have higher voltage and ampere rating. Make sure you use the switch that is rated for the voltage and amperes you are using.
Never exceed 80% of the ampere rating of a switch.
6) A switch in a wet location or outside of a building shall be enclosed in a UL listed weatherproof enclosure or cabinet. Switches shall not be installed within wet locations in a tub or shower spaces, unless installed as part of a listed tub or shower assembly.
If you are having problems, Play it Safe.
Make sure you check the regulations in the National Electrical Code regarding the device you are wiring. If you are still unsure of how to properly wire the circuit you are working on, you will need to contact
a qualified electrician in your area. You can also ask questions in our forum.
Single Pole Switches >
Three Way Switches
Related Resources: National Electrical Code Handbook
National Electrical Codebook
Stallcup's Illustrated Code Changes
The Complete Guide to Home Wiring (Black and Decker Complete Guides Series)
Guide to Using the National Electrical Code
Residential Remodeling and Repair Professional Reference
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