Methods to Wire A 3-Way Light Switch
There are three basic varieties of light switches. The first is a simple, single light switch. The second is a 3-way switch that controls one lighting fixture from two locations. The third is a 4-way switch that controls one lighting fixture from three or more locations.
The easiest method for three-way switches is to place the sunshine between the two switches. You have to look closely at an electrical wiring diagram to know.
The cable needs to be 12.2 Romex right as much as the first switch, then run 12.3 Romex to the sunshine and then on to the second switch.
The 12.3 Romex has an additional wire called a traveler (usually red), which is critical for 3-way switches.
At the primary switch, the 12.2 Romex from the circuit run enters the bottom of the switch box and the new (black) cable connects to the underside right terminal on the switch.
The 12.3 Romex enters through the top of the switch box. The hot traveler (red) wire connects to top left terminal on the switch. The black (hot) wire connects to the top right terminal on the switch.
The 12.3 neutral (white) wire connects directly to the 12.2 neutral wire with wire nuts and the copper ground wires are also connected along with wire nuts.
At the sunshine box, it’s best to have two ends of 12.3 Romex hanging out. One end comes from the primary switch the other end comes from the second switch.
First connect the copper ground wires along with a wire nut to get them out of the way, after which connect the 2 red traveler wires along with a wire nut as well.
Now find the black wire coming from the primary box and the white wire coming from the second box and connect them together with wire nuts. Now, that is important, you might want to mark each end of the white wire by wrapping it with black electrical tape. This means you’ve got made it a hot wire. This is a code requirement! It’s common practice for 3 and 4-way switches.
Now, on the second switch, you’ll connect the red traveler wire to the top left terminal. The white, wire now labeled as black with tape, connects to the upper right terminal. The black wire will hook up with the lower right terminal screw. The copper wire will connect to the box if it’s a metal box or the green ground screw on the switch if the box is plastic.