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3-Way Switch Wiring

Alternate 3-Way Switch Wiring Diagram 1, NM

3-way Light Switch Wiring Diagram 2


Line voltage enters the light fixture outlet box.

No longer allowed after 2011 NEC (if no neutral wire in switch boxes)


Alternate 3-Way Switch Wiring Diagram 2, NM

3-way Light Switch Wiring Diagram 3


Line voltage enters the first 3-way switch outlet box, light fixture is located between switch boxes. No longer allowed after 2011 NEC (if no neutral wire in switch boxes)

3-way Light Switch Wiring Diagram 1

3-Way Switch Wire Colors

There is no standard for wire colors on 3-way switch travelers. The colors will vary depending on whether NM cable or conduit was used.

With NM cable, the wire colors for travelers will be black and red using 3-wire cable.

With conduit, the wire colors for travelers could be any color. In the 2nd diagram below, blue wires are used for travelers.

Typical 3-Way Switch Wiring, NM Cable

In the 1st diagram below, a 2-wire NM cable supplies power from the panel to the first switch box. The black (line) wire connects to the common terminal of the first 3-way switch. A 3-wire NM connects the traveler terminals of the first and second 3-way switch together. Traveler wires are interchangeable on each switch.

The common terminal of the second 3-way switch connects to the light fixture(s).

The white neutral wires are connected together in each switch box.

Diagrams shown on this page are simplified for clarity. Electrical outlet boxes can have numerous NM cables going in and out. See Actual Switch Box Wiring. Ground connection diagram is shown separately.

With conventional wiring, line voltage enters the first 3-way switch box

3-Way Switch Wiring Diagram Example, Conduit

Typical 3-Way Switch Wiring Diagram, NM Cable

Common wire wrapped around traveler wires.

Black common wire is usually wrapped around the two traveler wires on a 3-way switch.

Electrical Switches

Light Switch Wiring

Multiple Switch Wiring

Duplex Switches

3-Way Switches

3-Way Switch Wiring

Alternate 3-Way Switch Wiring

3-Way Duplex Switches

4-Way Switches

4-Way Switch Wiring

Alternate 4-Way Switch Wiring

Dimmer Switches

Dimmer Switch Wiring

Photocells and Timers

Ceiling Fan Switch Wiring

Motion Detectors and Occupancy Sensors

3-way switch wiring diagram example, conduit