On/Off Switch + No Neutral + Fluorescent Tubes... Am I looking at the impossible?

Been having a hard time finding a simple on/off switch that will work with fluorescent tubes without requiring a neutral. I have pretty much all the commonly used areas in my home automated, except for my workshop. I have fluorescent tubes there and no neutral, at a complete loss on what to go with.

An in wall relay won’t work there simply isn’t enough space in the wall for one.

Is there room for an in-wall microswitch to mount inside the florescent fixture (near where the ballast is), or in the junction box in the ceiling?

There are no switches that I know of that will work with traditional florescent fixtures without a neutral.

Nope, and the fixture itself is mounted in a way that making any changes there would be pretty difficult right now. Worst case scenario I might have to wait till summer and rewire and replace the fixtures. Would there be any connected light tubes I don’t know of by any chance?

Lutron Caseta PD-5WS Will work with fluorescent tubes up to a five amp load without a neutral.


The question is how do you integrate it with SmartThings?

There are three basic options.

One) use IFTTT. This can work well as far as turning them on on a schedule. But smartthings won’t know if someone turned the light on at the wall switch. And there may be some additional lag.

  1. One community member has created an integration based on using an intermediary server on raspberry pi.
  1. don’t try integrating. Lutron switches work fine with echo, so you can group them for voice control with your SmartThings switches if you want. Other than that, just use Lutron’s own scheduler, HomeKit, Wink, or IFTTT.

What about this? I know it’s not a switch but seems like it would work as it is just an on/off thingy inside the tube light where the ballast is… I was going to pick up a couple to play around with. Thinking Christmas…

Lutron, is definitely a possibility, I guess now I just need to decide between getting the lutron now and using a pi to integrate, or just wait till summer and change the light fixtures like I originally planned.

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They do seem like a great option… Just way too scared to install these in side a wall. I just don’t want to risk a fire, its an old home so it will go up like a match stick.


I understand that!

Those are not UL listed and seriously not something to put inside a wall. Nor do I think they would work with the ballast.

I thought it just kinda opened/closed the circuit. You are probably right.

Good point-- I keep forgetting about the Fibaro dimmer because the switch does require a neutral and the dimmer has only been available on the US frequency for a few months. To use it with fluorescent tubes, you need to set it up as an on/off switch, but there’s a parameter for that. :sunglasses:

It’s still a little hard to find in the US, and you have to be careful to make sure that the one you’re buying is on the US frequency, not the EU frequency, but The smartest house now usually has it in stock.

Note also that there are some wiring differences between the 211 and the 212 so just check that carefully.

What kind of fluorescent tubes are you using? It may be worth looking at replacing these with LED tubes (here is an example that doesn’t require ballast changs) and then using a non-neutral dimmer

I don’t understand: how is that going to help? With the exception of the fibaro micro that @anon36505037 already mentioned (or the Lutron, which aren’t compatible with ST) all the dimmers which don’t require a neutral don’t work with LEDs, either.

The physics of LEDs is different than that of incandescents. LEDs are not a “resistive” load. This is why LEDs typically flicker when used with the older Z wave switches that don’t have a neutral.

The LED tubes aren’t going to be any different. There are some problems that they will solve, certainly, but not having a neutral at the switchbox isn’t one of them.

It looks like the drivers on some LEDs are able to go super low without flickering. Maybe I misread the thread, but I installed some dumb Cree LEDs on a smart non-neutral dimmer and they appear to work OK. I was thinking some if the fancier LED tubes might have the same capability. You end up paying a bit extra for the dimmer instead of a switch, but if you just tap the paddle then it doesn’t matter too much.

You got lucky. It happens, but you can’t count on it.


I was thinking about switching to led tubes I got from costco, they work with a ballast however and are non-dimmable so not going to work even if I wanted to try it out. I guess I’ll just remove the fixture when I get some time and see if I can install a micro switch.

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Pshh… luck has nothing to do with it. I had four different types of LED bulbs sitting on my counter to test. I am still evolving from light bulb nerd to smart home nerd :slight_smile: CNET actually did a study on this a couple years ago: Which LED bulbs are best for built-in dimmers? - CNET

Sorry I’m no help. You might (no promises) have some luck with something like these: http://www.homedepot.com/b/Electrical-Light-Bulbs-LED-Light-Bulbs/Dimmable/T8/N-5yc1vZbm79Z1z0u4xvZ1z0vvri (some require bypassing the ballast while others are plug and play). Also, you could potentially install LEDs that bypass the ballast, remove the ballast, and use the vacated space to install the micro switch.

No nerd cred until you cite brand and model for both the switch and the bulb in these kind of comments. :wink:

Yes, different LEDs perform differently with regard to flickers. That’s why the model numbers matter. If you find a combination that works, that’s great, but for situations like this you need to be specific.

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I am not home right now to 100% confirm, but believe the dimmer is a GE12724 (the Z-Wave model we used to sell in our shop) and the Cree is the TW 60W equivalent.

Can I get some type of nerd cred mic drop?

Not for that. The GE 12724 requires a neutral. :stuck_out_tongue_winking_eye: