Need help installing VZM31-SN without neutral

Product Support Wiring Discussion
, , , ,
1

Hi :waving_hand:

  • Model: VZM31-SN
  • Non-neutral setup
  • Single pole

I just installed the blue series fan/light canopy module in my ceiling fan, and looking to install the wall switch (VZM31-SN) to control it.

Here is the existing wiring:

LINE (HOT) ──────[ WALL SWITCH ]────── LOAD ──────┐
                                                  │
                                               [ FAN ]
                                                  │
NEUTRAL ──────────────────────────────────────────┘

In other words, I only have the line and load wires inside of the switch box, nothing else.

Installing the module was easy, since I can just connect the line and load wires in the switch box.

Is it possible to install the VZM31-SN switch with this configuration? Even if it becomes just a scene switch without pairing directly to the fan module?

Thanks for the help!

2

Do you have a neutral or a non-neutral configuration? Your opening says you have a non-neutral, but your drawing shows the hot originating at the switch box. Whether or not the neutral originates at the switch box isn’t clear from the drawing.

If you have knob and tube wiring, your drawing would make sense. It’s possible with THHN in EMT (i.e. individual conductors in conduit), maybe. Typically if the hot originates at the switch box, then the neutral should be there too.

Can you clarify?

Here is the wiring diagram page for the canopy module / switch.

3

If you only have Line and Load wires in your switch box, then that is what is called a “switch loop”.

While a VZM31 can be wired into a switch loop, you will not want to do so in this situation. The issue is that a ceiling fan is both an inductive (fan) and resistive (lights) load, but the Dimmer is only rated to handle a resistive load and may be damaged otherwise.

What you will need to do is modify the wiring in the ceiling box at the fan to send a Line and Neutral down to the switch box, and you can then connect the switch that way. You will not be able to physically disconnect the fan at the switch box anymore though, and will need to rely on the circuit breaker to kill power when needed.

Photos of the wiring in the ceiling box are helpful if you’d like further assistance with that portion.

4

Thanks both for the help!

I think the challenge is that the line wire in the switch box comes from the electrical panel, since it’s always hot. The only wire between the switch box and ceiling box seems to be the load wire.

I can take a photo later this weeks, but if that’s the case what you say would be impossible in my case right?

5

Unless it was wired by someone who had no idea how to run electrical wiring, or is a really old install using K&T, then the power from the panel doesn’t go directly to that switch box.

What color of wires do you have in the switch box? If black and white, which of the two is your line and which is the load?

When you’re taking photos, be sure to photo both the switch box, and the ceiling box that the fan is connected to… although this may require temporarily removing the fan.

EDIT/UPDATE:

This is likely what you have and what you will want to do…

image
image1920×1920 375 KB