In the 1st diagram below a 2 wire nm cable supplies power from the panel to the first switch box. Wiring diagram for a 3 way switch one of the many wiring diagrams showing different methods of wiring a three way switch circuit.
How To Wire A 3 Way Light Switch Family Handyman
3 way switch power to light first. Traveler wires are interchangeable on each switch. The hot source is spliced to the white wire which should be marked as being hot with black tap and run through to the common terminal of sw1 and from here the hot from the light is spliced through to the common terminal of the second 3 way switch sw2. A three way light switch is different than a traditional single pole light switch as it contains an extra screw to connect an extra wire. And finally a 2 wire switch leg is pulled from the second s3 to the nearest light and then to any other. The common screw may be located in a different spot on your 3 way switch than the location indicated in the drawings above but make sure that the wire indicated in the drawings to be connected to the common screw is connected to the common screw of the switch. Light is controlled by two three way switches with the light between the switches and the power first going through a switch then to the light and onto the second three way switch.
The correct wire must be connected to the common screw of a 3 way switch otherwise the switches will not control the light fixtures correctly. This electrical wiring diagram shows power into light switch box 1 wire to light from switch box 1 and from switch box 1 to three way light switch box 2. On the other three way switch the load wire the load is the wire that feeds power to the light fixture gets connected to the copper or black screw terminal. Note that in this case a larger than normal device box is required at switch 1 location due to box fill calculations most regular size boxes will only accommodate five wires. This 3 way switch wiring diagram shows how to wire the switches and the light when the power is coming to the light switch. Another dead giveaway of a three way switch is the absence of on and off markings.
On one of the 3 way switches a line or hot wire gets connected to the copper or black screw terminal. The ground wire is pigtailed with a wire connector at the switch boxes and the ceiling box. Typical 3 way switch wiring nm cable. This 3 wire is used for the travelers and the neutral. The black line wire connects to the common terminal of the first 3 way switch. Grounding screws often are furnished with boxes and are green.
In this situation you. A 3 wire nm connects the traveler terminals of the first and second 3 way switch together. The two hot wires of three wire cable connect to a pair of brass colored traveler terminals on each switch. In this diagram the incoming hot wire attaches to the first switchs common dark colored terminal. First meaning the closest s3 to power. In this light switch wiring diagram the power feed joins the circuit via the light fixture where a two wire cable c2 runs from the light to the first 3 way switch sw1 and a 3 wire cable c3 joins the two switches.
Then a 3 wire 143 123 is run between switches from the first s3 to the second s3. This is known as the common screw and its usually black instead of brass or silver.
Gallery of 3 Way Switch Power To Light First
