Submitted by lurkerNC2019 t3_zyrk8d in DIY

Hi All,

I had to install a new ceiling fan today and added a switch to make it a 3-way. I wanted to verify that this was acceptable (see schematic). It is different from the normal 3-way switch diagrams I see in that I had the hot input and the wires to/from the fan coming from the same receptacle. I used 14-3 wire to connect to the second switch, with the black and red wires as the travellers and the white as the return to connect to the fan input. So there is no actual neutral between the two switches. There is current flowing both directions, so I dont think there should magnetism issues and the system does function as anticipated.

Edit: Re-uploaded image because it was loading weird on mobile

https://preview.redd.it/filr2n2czy8a1.png?width=1543&format=png&auto=webp&s=1df88d25b5200836adff74d5830132bc7b8dbd79

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[deleted] t1_j27ksz3 wrote

[deleted]

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dilligaf4lyfe t1_j27yqn7 wrote

Just to caveat, it is a hazard if switches everywhere in a building don't have neutrals. The reason for the neutral requirements is any switch using the ground for a neutral (ie an occ sensor) will put up to 1/2mA on the ground. Harmless if it's one, but if you have 10 on a circuit, all of a sudden you have 5mA on the ground. Point being, it isn't purely a design consideration, there is a hypothetical safety concern. But yeah, it's incredibly unlikely to be one here.

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capacity04 t1_j2d3aaz wrote

Is that a recent code addition? I thought you only required a neutral if the switch required one. That is, a simple 3 way switch like above does not require a neutral at the box.

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dilligaf4lyfe t1_j2e6q94 wrote

Nope, 2011. Neutral isn't required if there is conduit or the box knockouts are accessible. Basically, if it's easy to add a neutral later it isn't required.

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[deleted] t1_j280cuk wrote

[deleted]

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dilligaf4lyfe t1_j2912zc wrote

Wasn't trying to correct you, was just elaborating for anyone else who comes across this thread.

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[deleted] t1_j2a2ogp wrote

[deleted]

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dilligaf4lyfe t1_j2ao50m wrote

Or because I think it's interesting, and maybe someone else wants to know why the neutral requirement exists? I'm just elaborating on the intent behind the code, obviously it's pretty rare that hazard would ever exist. Just wanted to point out why it's there to clarify that it isn't a pointless rule.

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[deleted] t1_j27nome wrote

[deleted]

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RL203 t1_j29qjq1 wrote

By that diagram, box 2 is the end of the line since he has not shown any other wire exiting box 2.

According to his post, all he did was add a second switch to control the light / fan. Now both switches are 3 way switches.

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Mr_Festus t1_j27rt8w wrote

Definitely not correct. This will work but it's not up to code and in no way should be considered correct. You really should follow the code for new work, even if you're not getting a permit.

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MyHeadIsCrooked t1_j28fpr0 wrote

You're fine. As stated earlier, either tape or use a sharpie to color the white wire black so that it's obvious it's not a neutral and it is a current carrying conductor.

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Ok_Fox_1770 t1_j29qvv3 wrote

I’m usually surprised when there’s a proper box holding the fan, some of the old stuff you run into… 18 years of surprises so far.

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Two-tune-Tom229 t1_j2aheld wrote

I'm making a copy of this and putting it in my wallet. Even though now being 70, and needing this diagram probably 20 times in my working past, it will feel good just to know now how to do a proper three way.(switch, i know the other way)

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bananabreadvictory t1_j2bd6pl wrote

acceptable wiring, just make sure to wrap each end of the neutral wire between switches with black or red electrical tape to indicate it is a hot wire otherwise someone may inadvertently wire it to the neutral in the future.

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