I have an existing dimmer and a toggle switch configured in 3-way configuration.

The toggle switch has a single 12/4 attached.

The dimmer has 2 12/3s (I guess). Both of the grounds are wired to a common ground. One of the 12/3s has the black wired to the dimmer and the white wired to common neutral. The second has a white and a red wire wired to the two red wires coming out of the dimmer.

I'm a little befuddled by the configuration. It seems like maybe the red/white pair are the travelers for the remote toggle switch, but I'm confused by the black wire coming out of the remote switch's 12/4.

It seems like maybe that's going to load (it's a light fixture). But, if that's going to load, what's going on with the other 12/3 in the dimmer box?

If any of that makes sense to you, is there a ZWave dimmer I can put here?



I may be describing the wires incorrectly. In my count, I'm including ground.

  • When describing cable, the ground is not counted - 12/2 consists of 2 current carrying 12 gauge wires, generally one black (hot), one white (neutral), and a ground wire, either bare, green or, if the cable is armored, a silver wire to aid in grounding the armor. Similarly, 12/3 is three current carrying wires, usually black, red, white (but other colors may be used for the hots), and a ground.
    – bib
    Commented Apr 3, 2016 at 17:53
  • Can you post photos of the boxes? Commented May 13, 2016 at 11:42

1 Answer 1


Well, I did a fair amount of investigating so I'll answer my own question here in case someone else comes across it in a search.

I have two switches. A primary switch with a dimmer and a secondary switch. The secondary switch has line, ground, and 2 travelers. The primary switch has 2 travelers and load.

That's why the secondary switch has only one wire group coming in and the primary has 2. One 12/2 is for the load and the other 12/2 has the travelers.

As for the ZWave switch for this configuration, there are myriad options. I did get a ZWave dimmer in there repurposing one of the travelers to get line into the dimmer box from the secondary box.

This, unfortunately, precludes putting the secondary switch in.

Most ZWave secondary remotes I've seen require a neutral line which I don't have in the secondary box.

There are some ZWave remotes that don't require a neutral but they're often powered by a small trickle of current that can cause LEDs to light dimly or for fluorescent ballasts to flicker and be damaged.

I have a plan for how to update this wiring so that I can get both switches to operate again and I'll update this answer if I come up with something.

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