VZW31-SN + AUX01: No-Neutral 3-Way With Power at Ceiling Fixture

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1

I’m looking for help confirming whether the Inovelli Red Series VZW31-SN and AUX01 auxiliary switch will work with my existing 3-way hallway circuit.

My goal:

  • Smart on/off control through Home Assistant using Z-Wave JS.

  • Physical, hardwired switches at both ends of the hallway.

  • No battery-powered remotes.

  • Prefer to reuse existing wiring without running new cable.

Existing wiring:

Switch Box 1:

  • One 3-conductor cable (black, red, white, ground).

  • White connected to the dark/common screw.

  • Black and red connected to the traveler screws.

  • No neutral bundle.

Switch Box 2:

  • One 3-conductor cable and one 2-conductor cable.

  • The two white conductors are spliced together.

  • Black from the 2-conductor cable connects to the dark/common screw.

  • Black and red from the 3-conductor cable connect to the traveler screws.

  • No separate neutral bundle.

Ceiling fixture:

  • Single integrated LED ceiling light.

  • Multiple cables and wire splices in the junction box.

  • The fixture’s black lead connects to the black conductor of a 2-conductor cable.

  • The white conductor from that cable is spliced with black conductors.

  • The fixture’s white lead connects to a separate white-wire splice.

I suspect this is an older 3-way switch loop with power originating at the ceiling, but that has not been verified.

I measured voltage at the switch terminals using a multimeter referenced to a metal box. The readings changed depending on switch position, but the box’s grounding was not independently verified, so I have not conclusively identified a constant hot.

Questions:

  1. Is this wiring compatible with the VZW31-SN and AUX01 in a no-neutral 3-way configuration?

  2. Which approved Inovelli wiring diagram matches this arrangement?

  3. Can the existing conductors be reused without pulling new cable?

  4. Which box would hold the smart switch and which would hold the AUX01?

  5. Would I need an LED bypass for a single integrated LED fixture?

All original wiring and switches are currently reinstalled and functioning normally.

I’ve attached photos of both switch boxes and the ceiling fixture. I’d appreciate help confirming compatibility before purchasing or changing any wiring.

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2

According to the manual, it seems like there should be no issue with a no neutral hookup with an aux switch.

You have power coming into Box 2 on the white wire, then going to Box 1 over the other white wire. Your black and red wires from the 3 wire cable are your travelers, and the black common in Box 2 is the load going back to the light.

Which box would you like the main dimmer in and which box do you want the aux switch in? As this is a no neutral hookup, you can choose either.

So, for your questions…

1 - yes

2 - depends on where you want the dimmer to be, may not be a 1:1 diagram for what you have.

3 - yes

4 - your choice

5 - likely

EDIT: Here’s the diagram matching what you have if you want to install the dimmer in Box 2. Your Box 2 would be the box on the left in this diagram while your Box 1 would be on the right in this diagram.

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BUT, if you want to install it in Box 1, it is possible, but won’t match the diagram above.

3

That’s perfect! Thank you for taking the time to look over my wiring and find the matching diagram. This is exactly what I needed to feel comfortable moving forward with the Inovelli switches.

I’ll go with the dimmer in Box 2 and the AUX01 in Box 1 as you suggested. I really appreciate your help and the detailed explanation!