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While replacing a failing 3-way toggle switch I noticed 2 unfamiliar things in the switch wiring:

  1. A white neutral. I have not come across switches with neutral connections in my limited time as a DIYer.
  2. The white neutral came from a 14/3 and had black tape.

I chalked down the tape to the installer needing to insulate an over-stripped back-stabbed conductor. But I checked the other switch to the same fixture and it also had a white neutral from a 14/3 but no black tape.

Questions:

  1. What is the purpose of wiring the switch this way with a neutral?
  2. What does the black tape indicate?
  3. Why does the other 3-way switch in the same 4-gang box (pic 2) not have a neutral connected?
  4. When I replace the switch with a 3-way rocker switch, is it just a simple wiring swap? New switch and old switch have the same screw colors (brass and black). There is nothing wrong per se, I'm just gradually replacing worn out and back-stabbed switches & receptacles.

I've uploaded 2 photos and added helpful captions.

Tools & hardware available: Basics, Wire stripper, multi-meter, non-contact voltage tester, switches, wire nuts, lever nuts and spare 14/2 cable.

PIC 2 - White wire with black tape.

Lower level 4 gang

PIC 1 - White wire without black tape.

Upper level 2 gang

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  • Appreciate a well-asked question. To your last point: yes, just swap the old for new, matching screw colors. Dec 22, 2023 at 18:12
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    The black tape marking (could be red, could be some other hot color) indicates that the white from a cable is NOT neutral. It has been repurposed.
    – Ecnerwal
    Dec 22, 2023 at 18:38
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    Self-taught DIYers often make the mistake of thinking that all white wires are neutrals. There was a time when neutrals were not needed for a certain common use--the switchloop. This is the arrangement where the line hot (B hot, W neutral) enters the outlet box. The W neutral is connected to the neutral of the fixture and that is the end of the neutral. Line hot is connected to one of the two conductors in a cable (one B, one W) going to the switch box. No mfgr offered a two conductor cable with a B and a R, so the W must be either the line hot or switched hot. Dec 22, 2023 at 20:59
  • @JimStewart This can be an answer.
    – crip659
    Dec 22, 2023 at 23:30
  • @AloysiusDefenestrate A second 3-way switch (not shown in my post) was an old wired Leviton that had a Yellow wire along with Red and Black. Matching screw colors didn't work as it didn't have screw terminals and the internal switch configuration was not known (no markings either). But with trial and error I got it to work as desired. Otherwise your advice worked for the 3way in question.
    – eszed
    Dec 26, 2023 at 14:02

2 Answers 2

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Neutral must be white(or grey),over a certain gauge size(I think it is 4 gauge and larger that can be marked as neutral).

White does not mean neutral. It should be marked as in your example, but quite a lot of times it is not marked(I put it in and I know reason).

It was used this way to save on copper/needing an extra unneeded wire. With smart switches, code changed to require white neutral to be in switch boxes, so these days for new switch boxes you must use a black/red/white cable even if the white neutral is capped and unused. This is for switch loops with power at the light fixture. Power to the switch first already has neutral in the switch box.

It can be a hot/live as in a switch loop or a 240 volt circuit that does not need neutral, or it can be used as a traveller wire between two three way switches.

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  • Thanks. Everything is working as desired now but it was quite a project as I had to replace 2 non-smart switches with smart ones. Since they require neutrals and with limited room and neutral length I had to get creative. Luckily lever nuts are easier to work with so I grouped neutrals and pigtailed between them after making sure they were on the same breaker. Same for the Line wire as I needed it for the dimmer. I had to repurpose the back-stabbed conductors after ejecting them. Each time I discard a back-stabbed device I sleep better at night.
    – eszed
    Dec 26, 2023 at 14:21
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These switches don't have any neutral wires.

The white wire is being used as a traveller. NEC requires the wire be identified with a marking such as black tape to indicate it is not grounded.

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  • It's a small nit to pick, but there are a lot of buildings out there wired decades or more before today's NEC. Not all neutrals are grounded and assuming a white wire without a band is grounded is unsafe. The black band specifically means that regardless the color of the wire, treat it as black/hot.
    – JBH
    Dec 24, 2023 at 1:02
  • @JBH As illustrated by the photo at the bottom of the question where the traveler is unmarked. I will edit the question to make it more obvious. Dec 24, 2023 at 3:00

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