3-Way Switch Wiring - Power Source at Switch Plus Ground Cable Routed thru the Ceiling Box to Other Switch

This article describes the wiring for a 3-way switch with the power source at the switch plus the ground cable routed thru the ceiling box to another switch.

Items to consider when wiring your 3-way switch:

• At the ceiling box--the ungrounded conductor (a.k.a. hot) for the fixture connect to the black wire coming from switch 2. The white wire from switch 1 is the grounded leg conductor (a.k.a. neutral) for the fixture. Connect the white wire from switch 2 to the black wire from switch 1.
• Wrap a piece of black electrical tape around both ends of the white wire going between the switch 2 and the fixture box, as this wire is also being used as an ungrounded switch leg (a.k.a. hot).
• Bare wires are together and grounded to box (if metallic) and if the fixture has a green wire or a grounding screw, it gets grounded also. Bares and green wires are equipment grounding conductors.

If You Need Onward Power From the Fixture:

If Only Switched Power Required Onward Then at Existing Fixture:

• Onward cable--black/white/bare
• Connect black from onward cable to the black wire coming from switch 2
• Connect white from onward cable to white wire coming from switch 1
• Connect bare from onward cable to bare coming from switch and to electrical box if metallic
• At the onward cables destination, the black is the switched ungrounded conductor (a.k.a. hot), the white is the grounded leg (a.k.a. neutral), and the bare is the equipment grounding conductor

If Only Unswitched Power Required Onward Then at Existing Fixture:
This is not possible with this configuration as there are no unswitched ungrounded conductors (a.k.a. hot) existing at the fixture location.

If You Need Onward Power From the Switch:

In this configuration only unswitched power is available at the switch 1 box. Switched power is not available at either switch 1 box or switch 2 box, as no grounded conductor (a.k.a. neutral) is available at switch 2 box, and no switched ungrounded conductor (a.k.a. hot) is available at switch 1 box.

If Only Switched Power Required Onward Then at Existing Switch Box:
This is not possible with this configuration.

If Only Unswitched Power Required Onward Then at Existing Switch Box:
(only possible at switch 1 box location)

• Onward cable--black/white/bare
• Connect black from onward cable to black wire coming from circuit power supply cable
• Connect white from onward cable to white coming from circuit power supply cable
• Connect bare from onward cable to bare coming from circuit power source cable and to electrical box if metallic
• At the onward cables destination, the black is the ungrounded conductor (a.k.a. hot), the white is the grounded leg (a.k.a. neutral), and the bare is the equipment grounding conductor

The common screw of a 3 way switch is the Odd color screw

If you are new at understanding the "politically correct" electrical terminology and need clarification of the terms used, we strongly urge you to read the Clarification of Definitions and Terminology guide. This will explain the terminology used in this article.