Three-wire electrical switches are very useful in a home, as they allow a light or outlet to be controlled by two different light switches instead of just one. Either switch can turn a light on or off independently of the other. This is ideal for stairways and large rooms, where you may wish to turn a light on from one location and off from another. Wiring a 3-wire switch requires some experience working with electrical components and it is important to follow safety precautions to keep yourself safe.
Things You'll Need
- 14-gauge wires, red and black in color
- 2 3-wire light switches
Turn off the main breaker in the breaker box before beginning any electrical wiring project. This ensures no electricity is running through the system and keeps you safe from electrocution.
Wrap the black wire coming from the main electrical box around the bottom-right screw of the first 3-wire switch and use the screwdriver to tighten the screw and secure the wire.
Wrap the white wire coming from the main electrical box around the positive terminal of the light fixture or outlet and use the screwdriver to tighten the screw.
Wrap a black wire around the negative terminal of the light fixture or outlet and the other end around the lower-right screw of the second 3-wire switch. Use a screwdriver to tighten each screw.
Wrap a black wire around the upper-right screw of the first switch and the other end around the upper-left screw of the second switch. Use a screwdriver to tighten both screws.
Wrap a red wire around the top-left screw of the first switch and the other end around the upper-right screw of the second switch. Use a screwdriver to tighten both screws.
Inspect all connections to ensure wires are tight and secure, then turn on the main breaker. Your 3-way switches will now independently control the light or outlet.
Tips & Warnings
- Be careful to never touch exposed wires or the screw terminals of a switch or outlet while the power is turned on.
- Photo Credit Medioimages/Photodisc/Photodisc/Getty Images
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