VZM31-SN No Neutral or Load for Smart Bulbs?

I have a VZM31-SN Blue switch that I was hoping to install without a neutral wire and without it physically controlling a load.

The switch box has a single romex cable with a line, load, and ground. It is a single pole circuit controlling an overhead light fixture.

I was wondering if it would be possible to simply connect the line and load so that the light fixture has power 24/7 (I have smart bulbs in that fixture), then come off that connection with a 3 conductor WAGO connector and pigtail into the switch’s Line input to give the switch power.

I guess what I’m trying to say is all I need the switch to do is be a remote of sorts and I’d set up all the automations in home assistant. I’m just not sure how to get power to the switch and the light fixture with the wires I have available in my junction box.

Here’s an image of my dumb switch all wired up:

I think what you are asking is can you connect the line and neutral to the light so that the light is powered full time. Then, can you pigtail the line, neutral and ground to the 2-wire coming from the switch so that you have a hot and neutral at the switch.

Yes, you can do that. Just be mindful that to be safe, you should cut the power at the breaker if you need to change the bulb, as that is now the only way to cut power to that fixture.

I think the easier connection would to hook up the switch in the no-neutral connection with those wires (so line to line, load to load, and ground to ground). You should then be able enable Smart Bulb Mode on the switch, which will leave your bulbs having continuous power while letting you setup your automations in Home Assistant.

This avoids you need to make any other wiring changes, and also lets you cut power to the fixture if you need to change the light bulb (by pulling the air gap) without flipping a breaker.

The problem with that is the switch May power cycle when the light is turned off. You could install a bypass or two to ensure enough current draw prevents the switch from power cycling. I would opt for @Bry ‘s wiring to ensure the switch stays powered up and not have to install a bypass or two. Just be mindful of the power being available all the time and the air gap on the switch won’t secure power at the light; only opening the circuit breaker will cut power if you wire it per Bry way.

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@Bry So I’d just put all the wires, including the ground wire, in a wire nut, and run a pigtail from that wire nut to the line input on the switch?

I tried this and the switch powers up, but I’ve got two Wyze bulbs at the fixture and I don’t think they exceed 25W because they flicker and won’t turn on when I try to turn on the load at the switch. So I’m guessing I’d need a bypass at the fixture which is what I’m hoping to avoid, but if that’s what’s needed then I guess I need to just suck it up and do it. :rofl:

I’m not sure, all my switches are in a neutral configuration, I was mostly going by the documentation. I would have expected the bulbs to be able to turn on basically fine, as the switch should be letting most of the power through and so a bypass shouldn’t be necessary. Just to verify, you did turn on “Smart Bulb Mode” in the switch?

I would have expected @harjms’s concern to be the more likely issue tbh. I agree @Bry’s solution would be an alternative answer, but with the same warning that your fixture would always be live and need special attention.

I think @Bry’s suggestion is to connect the light fixture directly to the line/neutral so your bulbs are always powered. You would then connect the black/white/ground wires going to your switch box to line/neutral/ground and connect those wires to line/neutral/ground connections on the Blue switch. I don’t believe he was suggesting to connect all three lines to a single wire nut (I’d expect doing that to cause an immediate short and pop a breaker).

Not sure what you mean by “all the wires” but if you literally bundle “all the wires” you will have a short.

I’m confused about how you are approaching this. When I responded to your first post, I explained that I THOUGHT you were asking if you could power both the light and the switch full time, leaving the light unswitched because it has a smart bulb. So I noted that you can power the light and the switch full time, with the warning that you should shut off the breaker if you have to change the bulb.

But from your description, it sounds as if you are still trying a non-neutral powering of the switch, as you’re now mentioning using a bypass, concerned about the 25W limitation, etc.

EDIT: I re-read your last post. One way or the other, you’re going to have to do something at the light. Since that is the case, even though you are trying to avoid that, I would wire a bypass at the light and see how it works.

Disregard trying to wire the light and switch hot full time. I think that you were thinking that you could do this without doing anything at the light, which is NOT the case.

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That makes sense. Yeah, I was wondering if there was a way to not have to do anything at the light fixture, and literally power the switch with a single pigtail from the line, but it sounds like that won’t be possible.

All good! I’ll just do a bypass at the fixture and see how that works. Thanks!

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Yeah I think you’re right. I did set the switch to smart bulb mode, but still experienced the flickering, etc. I think I just need to do a bypass at the fixture.

If you’re opening the light, which you must, then just connect the light and the wires going to the switch to constant power and run the switch with a neutral and no load. Basically, all the black get joined together and all the white wires get joined together in the light box.

Oh okay, cool! I’ll climb up and see what I’ve got in the light fixture as far as wires go, and then let you know if I’m confused at all. Your explanation made sense though – thanks for your help!

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Just so you are aware, that is exactly the same thing that @harjms, @mjdsys and I recommended, but you seem to want to use the non-neutral approach.

Oh sorry, my understanding is that I have to do some wiring up at the light fixture regardless of which method I use, right?

Yes, you have two options, both requiring work at the light:

1 - Keep the existing non-neutral and add a bypass at the light to see if that fixes the issue.

2 - Rewire at the light to power the light full time (requiring the breaker thrown to turn it off when changing the bulb, etc). As part of this, you can send the hot and neutral to the switch over the existing 2-wire between the switch and the light. This will only power the switch, which will no longer control the light via the wiring. You’ll have to use a scene or binding (if you bulbs are Zigbee) to turn the bulbs on and off.