Fan Always Hot, Light Switched - 3-Way Switches, Power at Switch, 3-Wire plus Ground Cable Routed thru a Ceiling Box

3 way switches, power at switch, 3 wire (plus ground cable being routed thru the ceiling box onward to other switch)

At the ceiling box - the ungrounded conductor {aka hot} from the fan connects to the black wire from the switch box 1 (on the 2 wire + bare cable {black/white/bare cable}). The ungrounded conductor {aka hot} for the light connects to the red wire coming from switch box 2. The white wire from switch box 1 (on the 2 wire + bare cable {black/white/bare cable}) is the grounded leg conductor {aka neutral} for both the fan and light. The red wire on the black/red/white/bare cable coming from switch box 1 is unused and just cap it off at both ends with a insulated wire nut. This will provide an unswitched ungrounded conductor {aka hot} for the fan and a switched ungrounded conductor {aka hot} for the light.

The reason for using a 3 wire + ground (black/red/white/bare) cable between switch box 1 and fixture (and not using the red wire) is to ensure that it will be easy to distinguish at the fixture the difference with the 2 cables coming from switch box 1 to help prevent the wrong two wires being connected. Using 2 wire + bare (black/white/bare) would make it more difficult to distinguish the 2 cables at the fixture and could end up with a dangerous combination of wrong wires being connected together.

Bare wires are together and grounded to box and if the fixture has a green wire or a grounding screw , it gets grounded also. Bares and green wires are equipment grounding conductors.

On the cable between switch box 1 and 2 (on the 3 wire + bare {black/red/white/bare}), wrap a piece of black electrical tape around the white wire (at both ends) (including the portion being looped thru the ceiling box) to indicate that this white wire is being redesignated and used as a ungrounded switch leg {aka hot}.

Be sure to read all documentation that comes with your fan / light combo fixture.

If you need onward power from the fixture then

If only switched power required onward then at existing fixture

• onward cable - black/white/bare
• connect black from onward cable to red wire coming from switch 2
• connect white from onward cable to white wire coming from switch box 1 (on the black / white / bare cable)
• connect bare from onward cable to the other bares and to electrical box if metallic.
• At the onward cables destination , the black is the switched ungrounded conductor {aka hot} , the white is the grounded leg {aka neutral}, and the bare is the equipment grounding conductor.

• onward cable - black/white/bare
• connect black from onward cable to black wire coming from switch box 1 (on the black / white /bare cable)..
• connect white from onward cable to white coming from switch box 1 (on the black / white / bare cable).
• connect bare from onward cable to other bares and to electrical box if metallic.
• At the onward cables destination , the black is the ungrounded conductor {aka hot}, the white is the grounded leg {aka neutral}, and the bare is the equipment
  grounding conductor.

If switched and unswitched power required onward then at existing fixture...

• onward cable - black/red/white/bare
• connect black from onward cable to black wire coming from switch box 1 (on the black / white / bare cable).
• connect red from onward cable to red wire coming from switch 2.
• connect white from onward cable to white coming from switch box 1 (on the black / white / bare cable).
• connect bare from onward cable to other bares and to electrical box if metallic.
• At the onward cables destination, the black is the unswitched ungrounded conductor {aka hot}, red is the switched ungrounded conductor {aka hot}, the white is the grounded leg{aka neutral} and the bare is the equipment grounding conductor.

If you need onward power from the switch then

NOTE: Onward power from the switch is only possible at switch box 1with this configuration as there is no grounded leg {aka neutral} available at switch box 2. The following onward power options is based on the switch 1 location.

If only switched power required onward then at existing switch

This option requires the use of the previously unused red wire going from switch 1 to fixture.

• onward cable - black/white/bare
• connect black from onward cable to red wire. At the fixture also connect the red wire coming from switch 1 to the red wire coming from switch 2
• connect white from onward cable to white wire coming from the circuit power supply cable.
• connect bare from onward cable to the other bares and to electrical box if metallic. (e) At the onward cables destination , the black is the switched ungrounded conductor {aka hot}, the white is the grounded leg {aka neutral}, and the bare is the equipment grounding conductor.

If only unswitch power required onward then at existing switch

• 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 other bares and to electrical box if metallic.
• At the onward cables destination, the black is the ungrounded conductor {aka hot}, the white is the grounded leg {aka neutral}, and the bare is the equipment grounding conductor.

If switched and unswitched power required onward then at existing switch

This option requires the use of the previously unused red wire going from switch 1 to fixture.

• onward cable - black/red//white/bare
• connect black from onward cable to black wire coming from circuit power supply cable.
• connect red from onward cable to red wire. At the fixture also connect the red wire coming from switch 1 to the red wire coming from switch 2
• connect white from onward cable to white coming from circuit power supply cable.
• connect bare from onward cable to other bares and to electrical box if metallic.
• At the onward cables destination , the black is the unswitched ungrounded conductor {aka hot}, red is the switched ungrounded conductor {aka hot}, the white is the grounded leg{aka neutral} and the bare is the equipment grounding conductor.

The common screw on a 3 way switch is the odd color screw

If wiring multiple fixtures be sure to check the following guidelines concerning how to do it and what not to do: Wiring Multiple Fixtures.

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.