The black line wire connects to the common terminal of the first 3 way switch. In the 1st diagram below a 2 wire nm cable supplies power from the panel to the first switch box.

3 Way Switch Wiring Diagram
3 way lighting switch wiring diagram. Pick the diagram that is most like the scenario you are in and see if you can wire your switch. Take a closer look at a 3 way switch wiring diagram. Wiring a 3 way light switch. In the above 3 way switch wiring diagram at each switch the black wire gets connected to the copper or black screw. With a pair of 3 way switches either can make or break the connection that completes the circuit to the light. Wiring a 3 way light switch is certainly more complicated than that of the more common single pole switch but you can figure it out if you follow our 3 way switch wiring diagram.
Power through 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. In the ceiling light fixture electrical box one black wire from a 3 way switch gets connected to the black load wire on the light fixture. This is also known as the conversion method since it is the easiest way to add a second light switch to an existing circuit. Twinearth from the ceiling rose to the first switch and three wires between the switches usually 3 core and earth cable. The 3 way lighting circuit which is often referred to as the two way and intermediate lighting circuit is a common arrangement usually found in large houses. Traveler wires are interchangeable.
Also included are diagrams for 3 way dimmers a 3 way ceiling fan switch and an arrangement for a switched outlet from two locations. 3 way switch wiring diagram depicting all wires in the ceiling junction box. So what you should see if you have correct 3 wire electrical cable romex is a black power white neutral and now a 3rd red wire. Regardless of what 3 way switch wiring diagram youre following youll need to use a 3 wire cable to connect the two 3 way light switches. Typical 3 way switch wiring nm cable. You must completely forget about the notion of a switch being a simple openclosed circuit and look at the diagram of the circuitry of this modern alternative.
More common in domestic properties. This might seem intimidating but it does not have to be. A three way switch is fundamentally different in its operation from a regular two way switch. A 3 wire nm connects the traveler terminals of the first and second 3 way switch together. The ground wire is pigtailed with a wire connector at the switch boxes and the ceiling box. Two way switching 3 wires.
Three way switching 3 wires. 3 way switch wiring diagram. Knowing how to wire a three way lighting switch comes down to understanding the operation of this contraption. If you are familiar with wiring a two way lighting circuit then the addition of an extra switching point will not be much of a problem. This is the 3 wire cable which you must have to wire a 3 way. On this page are several wiring diagrams that can be used to map 3 way lighting circuits depending on the location of the source in relation to the switches and lights.
Fixture between two three way switches. With these diagrams below it will take the guess work out of wiring.