Modifying ceiling fan switch for independent fan/light control -- Is it acceptable to run 14/3 alongside existing 14/2?

Question

I'm looking at modifying an existing fan installation setup that is wired in the typical 1980s builder-grade way: The power enters and leaves at the ceiling box, and there is a 14/2 switch loop with no neutral to a wall box that switches the fixture at the ceiling box. This ceiling box has a fan where the lights and fan motor operate concurrently from the single switch.

It is wired like this:

• 14/2 from the panel, supplying constant power
• 14/2 to the next room, supplying constant power
• 14/2 to the switch, serving as an always-hot conductor and a switched-hot conductor. Switched-hot runs the lights and fan motor together.

I want to modify this to have independent control of the lights and fan so I can start to think about dimmers and timers. To do this I will need separate switch loops for the lights and fan, and my understanding of modern code is that the wall box should have a neutral in it (and my future timer might require it).

To do this, I'm thinking of repurposing the existing 14/2 to the wall box as a power source (getting me the neutral I need) and then running a new 14/3 between the ceiling box and the wall box to control the fan connections:

• [no change] 14/2 from the panel, supplying constant power
• [no change] 14/2 to the next room, supplying constant power
• [repurposed] 14/2 to the switch, supplying constant power
• [new] 14/3 between the ceiling box and wall box, providing two switched hots and a neutral for the fixture.

I know this circuit would be okay if all of the unswitched cables went through a separate junction box, and only the 14/3 went into the fan box. It starts getting muddy for me when everything is together in my single ceiling box.

My questions:

1. Is this an okay configuration from a code standpoint?
2. Is this okay from a not-confusing-the-next-person standpoint? If not, how could I change my plan or wire markings to make it easier on them?
3. I understand that the current in each cable needs to be balanced, and connecting the fan-neutral to the line-neutral in the ceiling box would mess that balance up. Does the same thing apply to the grounds (which I didn't draw)? My gut instinct is to tie every ground together in every box, but that will make a loop from ceiling -> 14/2 -> wall -> 14/3 -> ceiling. Is that an issue?

Location: NC USA

Answer 1

This is 100% fine.

• Currents balanced - Check
• Grounds together - Check
• Neutral in box - Check

The only possible issue I see is box fill. For the switch box, it is usually easy to replace the box with a deeper box if the old one is too shallow. You might want to do that now even if you technically have enough space because it will make things easier in the future if you want to put in a fancier switch (speed control for fan/dimmer for light). If the ceiling box has a fill issue that is a bit more work to replace, but my hunch is that the ceiling box will be less of a problem.

Answer 2

You could add this Fan control and not have to do all the wiring.

You can remove the wall switch and replace it with the controller.

It dims the light, controls the fan speeds and has a timer.