Trouble with no-neutral smart bulb mode. Red series resets or flickers even with bypass

I’ve got a couple fixtures in my old house still without neutrals. I bought some LZW31-SN red series dimmers because I wanted to use smart bulb mode to control some Sengled Element Color Plus bulbs via Hubitat. Inovelli dimmers seemed like the perfect solution supporting no-neutral and smart bulb mode!

Unfortunately I’ve run into issues I haven’t been able to solve. Here’s the problem: the sengled bulbs turn on but almost immediately after the switch reboots itself.

Sometimes the bulbs will stay on when smart bulb mode is off but when transitioning between color mode and color temperature mode they’ll start to strobe like crazy.

I figured the problem was lack of a bypass causing the switch to lose power as the bulbs were booting, so I bought one and installed it. No change, the problems are the same! I even tried doubling up the bypasses which didn’t help. It seems like the Inovelli dimmer just hates the Sengled bulbs in a no neutral setup.

They work fine if I leave a single incandescent in the fixture with them but for obvious reasons I don’t want to do that.

Anybody have experience with Sengled bulbs in a no-neutral setup? Any thoughts on what I could try since I already tried a bypass?

The sengled bulbs work perfectly in my fixtures with Inovelli dimmers that have neutrals. It’s only the no-neutrals that have this issue. Hue bulbs also seem to work on the no-neutral fixture, it’s just the Sengled bulbs the dimmer hates. Hue bulbs are too expensive to use in all my no neutral fixtures, that’s why I want to get Sengled working.

Any help is greatly appreciated!

I spoke too soon. Hue bulbs don’t work well either. The switch tends to randomly reboot, especially when the bulb are dimmed to a low level. Sometimes the switch shuts down completely and has to have the air gap pulled to turn back on. This happens on two different no-neutral circuits both with aeotec bypasses installed.

Is it possible to make smart bulbs work at all with the red series on no-neutral circuits? I bought them specifically because of the no-neutral + smart bulb capability but it doesn’t seem to work with any bulbs.

What hub are you using. What is the firmware on the dimmer?

Hubitat, dimmers are on latest firmware 1.57

Can you try setting the max dim to 80%? In non-neutral that has resolved some issues for some users. If it works you can check the voltage at the load screw and see if you are ok sending a bit reduced voltage to the bulbs (most work within 10% of 120V, even down below 110V).

Setting dimming level to between 40-70% seems to result in some stability but the switch still occasionally reboots or totally shuts down, especially if bulbs are set low. Setting dimmer to 70+% results in an instant reboot.

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Well, you could re-wire to put constant power on the lights and then use the 2 wires to feed live and neutral to the dimmer. This is not to code, and you need to be careful and aware the light sockets always have line power on them. But, it would work. This is a do it at your own risk thing.

Your other option that I see is to keep installing parallel bypasses until that works.

I’m not comfortable with the “hard wire the power” option. I tried 2 parallel bypasses and it didn’t seem to improve the problems. I don’t understand why the dimmer is rebooting when supplying 100% power to the fixture with the relay disabled. Shouldn’t that be more or less equivalent to hard wiring the load?

In your case since you have a non-neutral, it’s the other way around. The fixtures are supplying power to the switch. Not enough, apparently, even with a bypass. For obvious reasons, non-neutrals can be finicky.

Have you confirmed that the parameter 21 = 0, parameter 22 = 0 and parameter 52=0?

And for older firmwares, Disable Local Control = yes, if it’s a separate setting.

I had 21=0, 22=0, 52=1 (on-off only mode). I set 21=0, 22=0, and 52=0 (no smart bulb mode) but now I get the bulbs strobing as if they’re in a fast reboot loop.

edit: with level set to max when I power on the switch it no longer reboots but the bulbs strobe randomly approx every 300ms out of sync with each other. I am able to turn the bulbs off from the hue app and when I turn them back on they sometimes stop strobing, other times they strobe again.

So to summarize I’m seeing really weird behavior in a non-neutral setup with a bypass and LZW-31SN using 5-6x hue bulbs in a single fixture. Here is the dimmer configuration:

  1. Dimming rate set to 0 (so power instantly applied)
  2. Smart bulb mode off
  3. No-neutral mode on
  4. Switch type - load only
  5. Local control disabled

And here are the symptoms with smart bulb mode OFF

  1. When dimmer is first powered on at 100% bulbs strobe randomly at approx 300ms intervals
  2. Turning bulbs off and back on sometimes stops the strobing. Sometimes it comes back when the bulbs are dimmed.

Here are symptoms with smart bulb mode ON or on-off-only but other parameters the same

  1. Dimmer will reboot randomly. Reboots every time when set above ~75%.
  2. Sometimes dimmer will go totally dark until air gap is pulled (seems to happen when bulbs are set very dim or off).
  3. Seems to stay stable as long as bulbs are bright

Everything is perfectly stable if 1 incandescent is put into the fixture with the smart bulbs (but I don’t want to leave it that way for obvious reasons)

I’ve seen these symptoms with 2 different LZW-31SN on two different no neutral circuits. I’ve tried no bypass, 1x bypass, and 2x parallel bypasses. Right now I’m only testing with the hue bulbs because the sengled cause even more problems.

This is kinda driving me crazy! I bought these specifically for being able to use smart bulbs in my non-neutral circuits without people cutting power to the bulbs via the switch all the time.

Have you thought about re-wiring to send line/neutral to the switch and just use scenes to control the hue bulbs? You’ll remove load, but at this point, it’s probably worth looking into…

You do have the line and load wires installed correctly at the dimmer? Reversing those can do funny things.

No, the dimmer uses current in the load to power itself. When you dim the bulbs their current draw is very low below the level needed to power the dimmer.

Right, which is the purpose of the bypass so that the dimmer can have power even if the draw from the bulbs is very low. The aeotec bypasses are labeled 1w, perhaps they just don’t permit enough current to keep the dimmer stable when smart bulbs are dimmed/off? If that’s the case then maybe Inovelli should update the description of the red series to say that it is not compatible with smart bulbs in a no-neutral setup.

I’m also baffled by the strobing behavior. With dimming rate == 0 and level set to 99 it seems like the dimmer isn’t supplying clean power to the bulbs. In that configuration I thought it would behave like an on-off switch minus the small current needed to power the dimmer but that doesn’t seem to be the case.

I double checked with a multimeter, line and load are not reversed. I’m not sure what else I can try here.

Well at least for the moment I’ve given up and removed the inovelli dimmers in favor of some dumb switches with covers. I just couldn’t get them to work reliably with smart bulbs on a non-neutral circuit. They’re great with a neutral but they just don’t work with smart bulbs + no neutral. Even 2x bypasses didn’t help.

Probably an effect of an incompatible bulb. Sorry to hear it didn’t work.

I tried both Sengled and Hue bulbs, neither worked in a no-neutral setup. I’d hope hue bulbs are not incompatible given how popular they are. I’m a bit disappointed that “work with no neutral” and “smart bulb mode” listed as features seems to mean “works with no neutral” OR “smart bulb mode” – smart bulb mode won’t work in a no-neutral setup.

With enough bypasses or a bypass that puts a larger load on the circuit it would likely work. I don’t know of a heavy duty bypass though and those things are expensive to just keep adding more of them to test with.

I’ve never needed to use a bypass, but was wondering - if you add more than one, are they installed in series or in parallel? I would think that it would only make a difference if they are installed in series (end-to-end)…?