Fan Light Switched Separately Power Source at Fixture

Connections Instructions:

(as depicted in the diagrams above)

At the Fixture box…

Two cable entering this box; one cable coming from switch and one cable from the ‘circuit power supply’

• a) connect the white wire from ‘circuit power supply’ cable (grounded conductor [neutral]) to the grounded conductor (neutral) of fixture.
• b) using an insulated wire nut connect / join the black wire from the ‘circuit power supply cable’ + the white wire coming from switch.
• c) using an insulated wire nut connect / join the black wire coming from switch + the switched ungrounded conductor (hot) from light (shown as black in diagram)
• d) using an insulated wire nut connect / join the red wire coming from switch + the switched ungrounded conductor (hot) from fan (shown as red in diagram)
• e) please see under important notes in regards to the equipment grounding conductor (bare wire)

At switch box…

One cables entering this box coming from fixture.

• a) using an insulated wire nut connect / join the white wire coming from fixture + two black wires that connect to one main screw of each of the switches.
• b) connect the black wire coming from fixture to the remaining main screw of one of the switches (this will switch the light of the fan/light combo fixture)
• c) connect the red wire coming from fixture to the remaining main screw of the other switch (this will switch the fan of the fan/light combo fixture)
• d) please see under important notes in regards to the equipment grounding conductor (bare wire).

Important Notes:

By electrical codes you MUST have at least 6 inches of wire in the electrical box itself, and also the wire must be able to reach at least 3 inches outside the box, it can fail an electrical inspection if the required min. wire length is not met. You may have the wires a bit longer (within reason) but they cannot be shorter. Also see the note on box fill further down in this article.

You are allowed to re-designate a white wire to be used as a hot (ungrounded conductor) in switch circuits but in those cases where a white wire is used in this manner, you must wrap a piece of black electrical tape around that white wire inside the box to signify that is being used as an ungrounded (hot) conductor.

You cannot re-designate a white wire that is actually connected to the light fixture itself. At the fixture itself, the white wire must be the grounded conductor (neutral) coming from the circuit power supply cable.

In the configuration depicted on this page, the white going between switch & fixture has been re-designated to use as a ungrounded conductor (hot) and therefore requires a piece of black electrical tape around both ends. The white from the ‘circuit power supply cable’ to fixture is a grounded conductor (neutral) therefore no re-designation has been done and NO black tape on the ends of that wire.

Use wire nuts of the correct size to join wires together. For fan / light combination fixtures, most likely it will have wire connections, the white wire is the grounded conductor (neutral) , any green wires are equipment grounding conductors, then there will be two other wires one will be the switched ungrounded conductor (hot) for the light, and one will be the switched ungrounded conductor (hot) for the fan. If you are confused please post to our forums for further clarification.

What is not shown in the drawings to avoid confusion, is that each wire cable also has a bare equipment grounding wire included. This wire is connected to a grounding screw in each electrical box (if the box is metal), joined either through the grounding screws in the box itself or via a wire nut to the bare wire of the next cable entering / exiting the box, it is also connected to any grounding screw (if there is one) on the switch itself, as well as any grounding screw at the fixture (green wires that attach to the fixture are grounds). Now if using a plastic box, it is made of a material that is non conductive, however some plastic boxes have a metal strip inside that can still be used to connect equipment grounding wires, in the event that it does not use wire nuts to join the bare grounding wires together. The equipment grounding wire (bare in most cables) must be electrical conductively joined throughout the circuit. Green wires are also equipment grounding conductors.

If there is an equipment grounding screw on the switch it may be green in color and be separated away from the main connections of the switch and likely part of the metal frame that is also part of the mounting structure of the switch.

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Extensions to this Switch circuit…

Be Aware that there is a limit by code on how many wires can be in a given size electrical box, when adding more wires to the same box you may have to install a larger and / or deeper box to allow space for more wires coming and out of the box.

Here is an article / explanation in regards to box fill calculations ‘Box Fill Calculation’

The instructions here are based on the fact that the circuit has already been wired to the configuration shown in this article and we are now making the wiring changes for onward power.

From the switch locations…

No onward power is available at the switch location because there is no grounded conductor (neutral) present at either switch.

From the fixture location…

At the fixture location both always on power and switched power is available.
(showing bellow the fixture portion of the circuit)

Onward Always on power…

Not shown in the diagram but the onward cable also has a bare wire (equipment grounding conductor) that also must be connected to all the other bare wires at the fixture electrical box.

Connection Instructions for onward cable (always on)

(only the changes to the wiring are described here)

• a) Using an insulated wire nut, attach / join – the white wire of onward cable + the white wire connected to the grounded conductor (neutral) of fixture + the white wire coming from ‘circuit power supply cable’
• b) Using an insulated wire nut, attach / join – the black wire of onward cable + the white wire coming from switch + the black wire coming from the ‘circuit power supply cable’

Identification of wires of onward wire cable…

Black – ungrounded conductor (hot – always on).
White – grounded conductor (neutral).

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Onwards Always on and switched power (one always on and one switched)…

(Using Fan switch for the onward switched power)

Not shown in the diagram but the onward cable also has a bare wire (equipment grounding conductor) that also must be connected to all the other bare wires at the fixture electrical box.

Connection Instructions for onward cable (Always on and switched power (one always on and one switched from fan switch)

(only the changes to the wiring are described here)

• a) Using an insulated wire nut, attach / join – the white wire of onward cable + the white wire connected to the grounded conductor (neutral) of fixture + the white wire coming from the ‘circuit power supply cable’
• b) Using an insulated wire nut, attach / join – the black wire of onward cable + the white wire coming from switch + the black wire of ‘circuit power supply cable’
• c) Using an insulated wire nut, attach / join – the red wire of onward cable + the red wire coming from switch + the red wire connected to switched ungrounded conductor (hot) of fan on fixture.

Identification of wires of onward wire cable…

Black – ungrounded conductor (hot – always on).
Red – switched ungrounded conductor (hot) from fan switch
White – grounded conductor (neutral).

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Onwards Always on and switched power (one always on and one switched)…

(Using Light switch for the onward switched power)

Not shown in the diagram but the onward cable also has a bare wire (equipment grounding conductor) that also must be connected to all the other bare wires at the fixture electrical box.

Connection Instructions for onward cable (Always on and switched power (one always on and one switched from light switch)

(only the changes to the wiring are described here)

• a) Using an insulated wire nut, attach / join – the white wire of onward cable + the white wire connected to the grounded conductor (neutral) of fixture + the white wire coming from the ‘circuit power supply cable’
• b) Using an insulated wire nut, attach / join – the black wire of onward cable + the white wire coming from switch + the black wire coming from the ‘circuit power supply cable’
• c) Using an insulated wire nut, attach / join – the red wire of onward cable + the black wire coming from switch + the black wire connected to the switched ungrounded conductor (hot) of light on fixture.

Identification of wires of onward wire cable…

Black – ungrounded conductor (hot – always on).
Red – switched ungrounded conductor (hot) from light switch
White – grounded conductor (neutral).

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Onward switched power (two switched onward)…. (two switched)…

(Using Light and and fan switch for two onward switched power feeds)

Not shown in the diagram but the onward cable also has a bare wire (equipment grounding conductor) that also must be connected to all the other bare wires at the fixture electrical box.

Connection Instructions for onward cable (Two switched power (one always on and one switched from light and fan switch)

(only the changes to the wiring are described here)

• a) Using an insulated wire nut, attach / join – the white wire of onward cable + the white wire connected to the grounded conductor (neutral) of fixture + the white wire coming from the ‘circuit power supply cable’
• b) Using an insulated wire nut, attach / join – the black wire of onward cable + the black wire coming from switch + the black wire connected to the switched ungrounded conductor (hot) of light on fixture.
• c) Using an insulated wire nut, attach / join – the red wire of onward cable + the red wire coming from switch + the red wire connected to switched ungrounded conductor (hot) of fan on fixture.

Identification of wires of onward wire cable…

Black – switched ungrounded conductor (hot) from light switch.
Red – switched ungrounded conductor (hot) from fan switch
White – grounded conductor (neutral).

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Onward switched power (only one switched)…

(from light switch)

Not shown in the diagram but the onward cable also has a bare wire (equipment grounding conductor) that also must be connected to all the other bare wires at the fixture electrical box.

Connection Instructions for onward cable (One switched from light switch)

(only the changes to the wiring are described here)

• a) Using an insulated wire nut, attach / join – the white wire of onward cable + the white wire connected to the grounded conductor (neutral) of fixture + the white wire coming from the ‘circuit power supply cable’
• b) Using an insulated wire nut, attach / join – the black wire of onward cable + the black wire coming from switch + the black wire connected to the switched ungrounded conductor (hot) of light on fixture.

Identification of wires of onward wire cable…

Black – switched ungrounded conductor (hot) from light switch
White – grounded conductor (neutral).

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Onward switched power (only one switched)…

(from fan switch)

Not shown in the diagram but the onward cable also has a bare wire (equipment grounding conductor) that also must be connected to all the other bare wires at the fixture electrical box.

Connection Instructions for onward cable (One switched from fan switch)

(only the changes to the wiring are described here)

• a) Using an insulated wire nut, attach / join – the white wire of onward cable + the white wire connected to the grounded conductor (neutral) of fixture + the white wire coming from the ‘circuit power supply cable’
• b) Using an insulated wire nut, attach / join – the black wire of onward cable + the red wire coming from switch + the red wire connected to the switched ungrounded conductor (hot) of fan on fixture.

Identification of wires of onward wire cable…

Black – switched ungrounded conductor (hot) from fan switch
White – grounded conductor (neutral).

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Foreign Users:

The colors of the wires depicted are based on the standards and code requirements / configuration in the United States and Canada. If you are viewing this site from a foreign country, your wiring standards and color of wires may be different but the principal and sequence of wiring will still remain the same. Therefore the information in this article may still be of use to you regardless of what country you may be in. Just translate the colors used here to the color of wires used in your country in regards to ungrounded (hot) conductors / grounded conductors (neutral) and equipment grounding conductors as well know applicable code requirements in your country.

WHILE EXTREME CARE HAS BEEN IMPLEMENTED IN THE PREPARATION OF THIS SELF-HELP DOCUMENT, THE AUTHOR AND/OR PROVIDERS OF THIS DOCUMENT ASSUMES NO RESPONSIBILITY FOR ERRORS OR OMISSIONS, NOR IS ANY LIABILITY ASSUMED FROM THE USE OF THE INFORMATION, CONTAINED IN THIS DOCUMENT, BY THE AUTHOR and / OR PROVIDER

By: Donald Kerr