Wall switches used to control ceiling light fixtures or other fixtures come in three types. In this diagram the incoming hot wire attaches to the first switchs common dark colored terminal.
3 Way Switch Wiring Diagram House Electrical Wiring Diagram
Three wire switch schematic. In the 1st diagram below a 2 wire nm cable supplies power from the panel to the first switch box. Most common is the single pole switch the type used to control a light fixture from a single locationthe next most common is the three way switch which is commonly used to control a light fixture from two different locations. Three wire cable runs between each switch and the light fixture. A three way switch is not really three ways at all but it does have three screws on the back side. This might seem intimidating but it does not have to be. Traveler wires go on the brass screws.
With these diagrams below it will take the guess work out of wiring. For example a long hallway or stairway might use a pair of three way. The traveler wires are spliced at the fixture box to run between the traveler terminals on the switches they are not connected to the light. 143 with ground or 123 with ground wire best to use between switches. A 3 way switch has three screws plus the green grounding screw. There is only one such terminal on a 3 way switch and it is usually identified as the one having a different color terminal screw often significantly darker from the other two.
The two hot wires of three wire cable connect to a pair of brass colored traveler terminals on each switch. With conventional wiring the common wire from one switch connects to line the common wire from the other switch connects to the load lights. Pick the diagram that is most like the scenario you are in and see if you can wire your switch. Typical 3 way switch wiring nm cable. All of the switches shown below are 3 way. 3 way switches have three terminals one common usually black color and one pair of travelers usually brass color.
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. Below is a simple 3 way schematic that can be applied to all three way electrical light switch connections. So the electrical path is always through the switch it just changes it from one line to the other. Traveler wires are interchangeable. The most important screw is the black one 3 way switch diagram tips. One of the screws is the common and when you flip the switch it either connects this wire to one or the other of the two remaining screws.
The common terminal on sw2 is connected to the hot terminal on the light. This 3 way switch wiring diagram shows how to wire the switches and the light when the power is coming to the light switch. Watch all videos below for easy steps. The hot source wire is connected to the common terminal on sw1. The black line wire connects to the common terminal of the first 3 way switch. The 2 wire cable feed from the power source enters the bottom of the switch box and the hot black wire connects to the common or shunt terminal on the 3 way switch.
Take a closer look at a 3 way switch wiring diagram. A 3 wire nm connects the traveler terminals of the first and second 3 way switch together. Continuous hot and light feed wire goes on black screw.
Gallery of Three Wire Switch Schematic
