Connecting two light switches to control the same light fixture from two different locations is a common task for many homeowners and DIYers. With some basic electrical knowledge and supplies, this project can be accomplished in just a few steps.
Understanding the Basics of Wiring Light Switches
Before diving into the specifics of wiring two switches to one light, it's important to understand some electrical basics.
How a Standard Light Switch Works
A standard light switch has two terminals - one for the incoming power source and one for the outgoing wire to the light fixture. When the switch is flipped on, electricity flows through and completes the circuit to turn on the light. When the switch is flipped off, it breaks the circuit and turns the light off.
The Need for a Three-Way Switch
A three-way switch has three terminals - one for incoming power, one for the light fixture, and one that connects to the other three-way switch. This allows either switch to turn the light on or off.
Understanding the Lighting Circuit
The complete lighting circuit consists of the power source, the light switch, and the light fixture. The switch acts as a point in the circuit to control the flow of electricity to the light.
What You'll Need to Connect Two Switches to One Light
Connecting two three-way switches to a single light fixture requires a few basic supplies:
- Two three-way switches
- Electrical box for each switch
- Romex 14/2 cable
- Wire connectors
- Wire stripper
- Voltage tester
Safety gear like glasses and gloves are also recommended when working with electrical wiring.
Step-by-Step Installation
With the supplies gathered, you're ready to install two three-way switches to control one light fixture. Follow these steps:
1. Turn Off Power
The first step is to turn off power to the circuit at the main breaker panel. Verify power is off with a voltage tester. Make sure to turn off the right breaker usually marked "LIGHTING".
2. Install Electrical Boxes
Install a single gang electrical box for each switch according to code. Boxes should be securely mounted at the desired switch locations.
3. Run the Cable
Run the 14/2 Romex cable from the light fixture electrical box to one switch box, from that switch box to the second switch box, and finally from the second switch box back to the main light fixture box. Leave extra wire at each end.
4. Connect Switches and Lights
Refer to the wiring diagram and connect the black (hot), white (neutral), red, and ground wires to the appropriate terminals on each switch and the light fixture. Use wire connectors to secure the connections.
5. Mount the Switches and Fixture
With all wires securely connected, mount the switches in their electrical boxes and the light fixture in its box. Attach the switch plates and light fixture cover.
6. Restore Power and Test
Go back to the breaker panel and restore power to the circuit. Use the voltage tester to verify. Flip each switch to test that the light turns on and off from both locations.
Three-Way Switch Wiring Diagram
Here is a standard wiring diagram when connecting two three-way switches to control one light fixture:
The power source comes into the fixture box. The black (hot) wire then travels to switch 1. The red and black wires run between the two switches. The red wire carries the switched power back to the light fixture.
Tips for Easy Installation
- Use the right size wire gauge for the amperage rating of the circuit
- Maintain 1/4" of bare conductor when stripping wires
- Make sure wires are fully inserted in terminals and secure with screws
- Wrap connections clockwise to avoid wire nut failure
- Position the wiring neatly inside the switch and fixture boxes before mounting
Following basic wiring safety and neatly routing the cables will lead to an easy and successful installation.
Alternatives to Consider
While wiring two three-way switches is a common and effective technique, there are a couple alternatives worth considering:
- Smart switches - Allow remote control of lights via smartphone or voice control. Require neutral wires.
- Wireless switches - Operate lights without wiring switches together. Also needs neutral wires.
- Smart bulbs - Bulbs like Philips Hue can be controlled remotely without rewiring. Just screw into a lamp or fixture.
Conclusion
Installing two three-way switches to control one light fixture from two locations is a straightforward DIY electrical project. Following the wiring diagram carefully and maintaining safe practices are key. The result is an easy way to control a light from multiple places in a room or hallway.