3-way switches enable you to control a light fixture from two different places in one room. For example, a hallway is a great place to install three-way switches for added convenience! 3-way light switches feature unique wiring connections and are always used in twos. You can wire a 3-way switch yourself in a few hours! Wiring a 3-way switch is more complex than a single-pole switch, but with a little bit of preparation and determination, you’ll be able to tackle this DIY project. Below, you’ll learn more about 3-way light switches and how to install 3-way switch wiring in your own home.
3-way Switch Features
If you’ve already installed a single-pole switch, you’ll notice that a 3-way switch is quite different! The switch itself is thicker and you’ll also notice that the words ‘ON’ and ‘OFF’ aren’t written on the switch. Because a three-way switch allows you to control one light fixture with two different switches, the switch may turn the light on or off.
The most obvious difference between these two switch types is the screw terminals. Three-way switches feature a grounding screw that is connected to the metal strap to hold the switch in place, plus three other screw terminals. A single-pole switch has just two screw terminals and the ground screw.
On a 3-way light switch, one of the screw terminals is darker than the other two. This terminal is called the “common connection.” Its job is to deliver an electrical current from the switch box to one of the two switches or to deliver the electrical current from the second switch to the electrical fixture.
The other two screw terminals are called “traveler terminals.” These terminals connect the circuit wires that are between the two switches. These circuit wires are called “traveler wires.”
Different Types of 3-way Switch Connections
You should always opt for screw terminal connections for your three-way light switch wiring. There are a few other ways of connection which vary by brand. As a rule, all 3-way switches wiring will feature screws on the side, but some will also have push-fitting slots or holes that you can slide the wires into. There are also other types that feature an easy-to-install spring-loaded slot with the screw terminals in order to hold the wires in place.
These types of fittings can seem attractive as they are the easiest way to connect a switch, but you should avoid them as they aren’t as secure as screw terminals. Opt for screw terminals – all professional electricians swear by them!
How to wire 3-way Switch Wiring yourself
You can set up 3-way light switch wiring yourself in five easy steps! In order to install your three-way switch wiring for your light fixture, you’ll need to identify whether the power comes to the light fixture first or to the light switch. The light switch first is the most common scenario, but you’ll want to confirm which one you’re working with before you get started on installing your 3-way switch wiring.
Step 1: Using your electrical panel, turn off the proper circuit.
Step 2: In your basement, install an electrical box for the second three-way switch. You may have to replace your current switch box with a larger one. There will be a lot more wires that you’ll need to house, so it’s always better to upgrade your switch box to make room for the extra wires!
Step 3: Run a length of type 14-3 NM cable between the two boxes to connect them. If you’re connecting to 12-gauge wire, you’ll need to use type 12-3. The 14-3 NM cable will feature three insulated conductors in three different colors: white, black, and red. There will also be a bare grounding wire.
Step 4: Connect the three wires to the three-way switches using the ground screws:
- If the power comes to the light switch first, attach the hot wire to the first switch’s dark screw terminal. Connect the three-wire cable’s two hot wires to the traveler terminals for each switch. Connect the hot wire for the light fixture to the common connection for the second switch.
- If the power comes to the light fixture first, attach the black hot wire to the switch on the right’s common connection. Link the blue and red wires to the traveler terminals for each switch. The red wire will connect back to the light fixture as it is connected to the first switch’s common connection.
Step 5: Be sure to wrap the ends of the white wires that are being used as traveler wires between the three-way switch wiring with black electrical tape. And, if you’re installing a three-way switch with the power coming from the light fixture first, make sure to put black tape on the white wire that connects the switch to the light. White wires are usually considered neutral in wiring, but because you’ve placed the black tape, you’ll know that they’re active and potentially dangerous.
Don’t let the process intimidate you, it is possible to install 3-way switch wiring yourself! The most common mistake that inexperienced home renovators encounter with switches is improper wiring. To avoid this, make sure to take the extra time to label the wires before you take them out of the old switch. The most important wire to label is the wire that is connected to the common screw terminal.
This wire must always connect back to the dark terminal screw, that common connector. You should also try to remove and reinstall one wire at a time. This can help you avoid any extra confusion as you install your brand new 3-way switch wiring! Mark your wires and work one wire at a time and you’ll be able to enjoy your new three-way switch wiring before you know it.