Red 2-1 flickering or buzzing (leading vs trailing)

I have an Inovelli Red 2-1 dimmer wired with a neutral. It was controlling fluorescent tubes with magnetic ballasts in on-off mode (officially not supported but worked fine with the neutral wire).

The Inovelli compatibility app shows the Toggled D416-65321-2 (6500K) as compatible in a neutral setup. I bought the D416-40321-2 (4000K) which should be identical save for the color temperature. Wired them up per the instructions that came with the bulbs.

However, the new bulbs flicker from 60-100% brightness. My switch is set up in a 3-way with a smart aux switch, configured as follows:

  • Parameter 21 = 1 (neutral)
  • Parameter 22 = 2 (multi-way with aux switch)
  • Parameter 158 = 0 (dimmer mode)

It looks like until the new firmware is released, I can switch to leading edge dimming by setting parameter 22 to 1 (multi-way with dumb/toggle switch). Doing that does eliminate the flicker, and the blubs dim from 1%-100% just fine. However, they buzz audibly instead.

I could probably live with the buzzing, but my multi-way switch doesn’t work with this setting, so until the new firmware comes out, I am stuck with flicker.

Since this is supposed to have been a compatible bulb, did I do something wrong? Or do I need a bypass even though I have a neutral wire?

Two possibilities:

When that compatibility app was built, the submissions were from users using Gen 2 switches and dimmers. The Red 2-1 is a newer generation, so my guess is that the bulbs listing in the app were compatible with Gen 2 devices. So a bulb compatible with a Gen2 dimmer may not be compatible with a Red 2-1 in the dimmer mode.

Unfortunately, the form users fill out only specified dimmer, switch or fan switch. That worked fine for back then, but now that there is a newer generation of devices, there will need to be a way to differentiate between the Gen 2s and the newer devices. My GUESS is that the 6500K bulb is compatible with a Gen2 dimmer.

The other possibility is that since you didn’t buy the exact bulb, it’s possible that the color temperature alone may be a factor. I agree that the two bulbs ought to be the same, though, so if I had to go with something, I’d go with the Gen2 vs the 2-1s.

For the record, the Aeotec Bypass did not help at all. So I think I just have to wait for the firmware update. Until then, I switched to some random old LED tubes a friend found in his garage. Looks like Keystone makes some dimmable tubes, will try those out too.