Connect the incoming phase conductor to the common terminal of the first wall control unit, then route a pair of traveler conductors between both control points. The common terminal of the second device links to the fixture’s hot lead. This arrangement allows power to reach the lamp through alternate paths depending on handle position.
Use 14/3 or 12/3 cable between both control boxes in most residential installations. The cable contains a ground conductor plus three insulated conductors commonly colored black, red, and white. Black or red often serve as travelers, while the white conductor typically returns toward the fixture or supply depending on box placement.
Inside the ceiling box, connect the neutral conductor from the supply directly to the fixture neutral lead. The controlled hot conductor arriving from the second control unit attaches to the lamp hot terminal. Ground conductors from all cables bond together and attach to metal boxes or grounding screws.
Maintain consistent conductor identification across both boxes. Mark repurposed white conductors using colored tape if they carry phase potential. Secure all connections using listed wire connectors and tighten terminal screws firmly to prevent heat buildup during operation.
Two Light Switch Wiring Diagram Showing Dual Location Control for One Lamp
Connect the supply phase conductor to the common terminal of the first wall control unit. Run a three-conductor cable between both control boxes so traveler conductors carry the current path that changes depending on handle position.
The typical cable used between control points contains these conductors:
- Black conductor used as traveler
- Red conductor used as traveler
- White conductor used as neutral or marked as hot if repurposed
- Bare or green conductor used for grounding
Traveler conductors attach to the brass screws on each control device. The common terminal usually appears darker than the traveler screws. One common terminal receives supply phase, while the other common terminal connects to the fixture hot lead.
The fixture box requires three main connections:
- Neutral from supply connected to fixture neutral lead
- Hot conductor arriving from the second control point connected to fixture hot lead
- All grounding conductors tied together and bonded to the metal box
Traveler conductors never connect to the fixture directly. They only run between both wall control devices and allow the current path to change depending on lever position.
Most residential installations use 14 AWG conductors on a 15-amp branch line or 12 AWG conductors on a 20-amp branch line. Cable length between boxes usually ranges from 1 to 15 meters depending on hallway or staircase layout.
Before energizing the line, confirm terminal screws are tight, insulation remains intact near connection points, and grounding conductors are bonded to both device boxes.
Connecting Line Load and Traveler Wires Between Two Wall Switches
Attach the incoming phase conductor from the electrical panel to the dark common terminal on the first wall control device. From that box, route a three-conductor cable to the second control point. The red and black conductors act as travelers and connect to the brass terminals on both devices. These conductors carry the alternating path that determines whether the lamp receives power.
The load conductor leading to the fixture connects to the dark common terminal on the second control unit. Traveler conductors never connect to the fixture; they only link the pair of control devices. Maintain correct conductor identification during installation: black or red typically serve as travelers, while the incoming hot attaches to the first common terminal and the outgoing lamp lead attaches to the second. Tighten terminal screws firmly and keep insulation close to the terminals so exposed copper does not extend beyond the screw clamp.