How to wire a light switch in the USA

3 way light switch circuits with multiple lights

threethreeThese 3 way switch circuits control multiple lights

Two lights between 3 way switches with the power feed via one of the light switchesTwo lights between 3 way switches (power via a switch)
Two lights between 3 way switches with the power feed via one of the lightsTwo lights between 3 way switches (power via a light)


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3 way light switch circuit wiring diagrams

Three way switch lighting circuit diagrams

Here is our selection of three way light switch circuit diagrams. This is where two switches control the same light (or lights).

The electrical symbol indicates where power enters the circuit.

3 way switch lighting circuit diagram with the power feed via the light switchThree way light switch with the power feed via the switch (single light)
3 way switch with the power feed via the lightThree way light switch with the power feed via the light
Single light between 2 way switches with the power feed via the switchSingle light between 3 way light switches (power via switch)
Single light between 3 way switches with the power feed via the lightSingle light between 3 way light switches (power via light)
3 way switches controlling two lights with the power feed via the switch3 way light switch with power feed via the switch (two lights)
3 way switches controlling two lights with the power feed via the light3 way light switch with power feed via the light (two lights)
Two lights between 3 way switches with the power feed via one of the light switchesTwo lights between 3 way light switches (power via a switch)
Two lights between 3 way switches with the power feed via one of the lightsTwo lights between 3 way light switches (power via a light)


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3 way light switch with power feed via the switch (two lights)

Here we have multiple lights controlled by 3 way switches.

The hot from the power source (cable C1) connects to the common terminal of the first 3-way switch (SW1) and the neutral is spiced, in the switch box SB1, through to the second 3-way switch (SW2) via the 3 wire cable (cable C2, that also carries the travelers that connect the two switches) where it is spliced through to the first fixture (F1) and connects with the neutral of each light. In the same way, the hot from the common terminal of the 3-way switch SW2 connects to the hot terminal on each light via cable C3 (spliced in fixture F1).
Circuit diagram for 3 way switches controlling two lights with the power feed via the light switch


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3 way light switch with power feed via the light (two lights)

The power, cable C1, joins the circuit at the light fixture F1. Here the neutral connects to the light F1 and is spliced through to light F2. The hot from the power source is spliced through both fixtures and terminates at the common terminal of SW1 via cable C3.

The travelers of each switch are connect together using cable C4 (taped white and red wires).

The taped white wire of cable C3 is the hot to the light LT2 (where the red wire of cable C2 is used to splice the hot to the next light, LT1).
Circuit diagram for 3 way switches controlling two lights with the power feed via the light


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3-way light switch with power feed via the light switch

Here we have a single light controlled by 3 way switches.

The hot from the power source connects to the common terminal of the first 3-way switch (SW1) and the neutral is spiced through (SB1) to the second 3-way switch (SW2) via the 3 wire cable (C2, that also carries the travelers that connect the two switches) where it is spliced through (SB2) to the neutral terminal of the light. The hot from the common terminal of the second 3-way switch (SW2) is connected to the hot terminal of the light.

3 way switch circuit diagram with the power feed via the switch (single light)


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3 way switch (single pole, double throw or SPDT)

3-way-switch-operation

Browse lighting diagrams that use a 3 way switch
You may also be interested to see how a two way switch works
You may also be interested to see how a four way switch works

A 3-way switch will usually have 4 screws. Most older 3 way switches only have 3 screws. The difference between the older and the newer switch is, the ground screw. Code changes over the years have required the addition of the ground screw for safety reasons. However, it is not needed for the correct operation of the 3 way switch. It is needed for the safe operation of this switch or any other type of switching device. On some switches the colors of the screw terminals are different to differentiate between the common and traveler screws. Some switches are made differently from others so the colors used may differ between manufacturers. The common screw will nearly always be a different color from the traveler screws.


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