California 3 Way Switch Diagram. At each switch in the above 3 way switch wiring diagram the black wire gets connected to the common copper or black screw. Conventional 3 way wiring is not very complex with conventional wiring the line line voltage connects to the common of one switch.
3 way switch wiring diagram depicting all wires in the ceiling junction box. How to wire 3 way switch. Three wire cable runs between the switches and 2 wire cable runs to the light.
The alternate 3 way switch wiring configuration california or west coast was used as a way to wire 3 way switches and be able to supply line voltage to either switch this configuration is no longer allowed as the neutral is not present in each switch box.
Take a closer look at a 3 way switch wiring diagram. The 2 diagrams below shows a 4 way added into the traveler wires and yet the light stays on even after the 4 way switch is flipped. 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.
