Evolve LFM-20 How To Wire

So is anyone using the LFM-20 in place of a basic light switch. I just need to control a load with this device but I don’t really understand how to do this with the 2 blue wires. I get those are for connecting a relay in parallel but I just need to control a hot line coming in to the LFM-20 and out to the load… Any help or guidance is much appreciated. Thanks!

Well, there is a diagram at http://shop.haworldonline.com/Evolve-Z-Wave-20A-Isolated-Contact-Fixture-Module-Model-LFM-20-11248.htm. I’ve never used one of these, but it shows it connecting to a switch with the yellow wire. It’s unclear what the switch is. Is it just a normal switch?

The blue wires look like they go to the load.

Look at the diagram and see if that helps. If not, perhaps that web site can provide more information?


Thanks Todd,
I’ve actually looked over the various diagrams. This model doesn’t have the yellow wire.

I tested it like this:

Black line wire (hot coming in) - wired to black
White - white
Green - ground

This leaves the 2 blue wires. When I flip the breaker on I tried testing the blue wires to see which wire would light up hot with the LFM-20 in the on position and neither blue wire seems to carry the load. I see most folks are using this as a means to close garage doors but I was hoping to control a simple load.

Edit: I went ahead and read that link again and this caught my eye; “It does work as a 220VAC switch, however please note that it is NOT a double pole switch, therefore, it can only control one of the two legs of 120V line wires, leaving the second unswitched or live.”

OK so I think it should work like a single pole switch though? Which is what I basically need it to do. I’m just not sure about their diagram…

When the relay is on the two blue wires will have continuity. You can connect one blue wire to your input black (hot) 110 vac line and then the other blue wire to black wire that feeds your load. Basically you’re routing your 110 line through the blue wire. When the switch is off it will interrupt the 110 hot line and when the switch is on will pass the 110 to your load. Hopefully that makes sense. Good luck.

I’ll give this a shot tonight. I appreciate the follow up!

Edit: wont I need to power the black wire as well? I believe that powers the LFM-20 itself? If so, I’ll include it with the hot line coming in…

Hey guys, I appreciate the replies but I just don’t think this unit is built to do what I’m trying to do. I’ll give it to tomorrow to see if anyone else has ideas.

Just to update, when I wire the hot wire coming in directly to one of the blue wires the switch doesnt break continuity or move the “open” position. Meaning my load would always be hot…

Garage door examples aren’t really applicable to my needs.

Its possible I have a dud. Not quite sure. I may just move on to a normal binary on\off switch but I wanted something I could hide inside an electrical box… Thanks All…

If you want an internal way to switch the load off and on from ST, have you considered the aotech module:

It’s very small, fits in a box. It’s designed to hook to a switch loop and when it detects a state change on the switch, it turns on the load.

There are six terminals. White and black line, white and black load and switch loop.

The switch loop is optional. If you just wire load and line, you can control it from the ST hub.


Perfect. Thanks Todd.

Patrick. You can use the lfm-20 for this. You will need to split the hot lead. One will power the device the other will be your 110vac input to the blue wire (doesn’t matter which one). The other blue wire will be your 110vac output to feed your load. The site would not let me upload a schematic due to being a new user but I could send you one if you want to try to use the LFM-20. LMK.

I wouldn’t mind still using it since I have it… However, I tried what you suggested and my load output always stayed hot no matter if the switch was turned off or on.

I used a wire nut to connect the 110vac (black) input coming into my box with one of the blue wires, and the black wire on the LFM-20.

The other blue wire was always hot… I can try it again but my tester was going nuts regardless of the switch being on or off.

Do I need to split the hot lead coming in or is using the wire nut essentially the same as splitting of the lead twice?

Sorry that it didn’t work. Can you hear the relay clicking when it goes off and on? If you can post a pict of your wiring maybe I can see an issue. Or, If you can wait another day I should have time tomorrow to try it on my Lfm-20 and then I can share the results with you.

Hi Matt,
If you want to upload the diagram and test it on yours, that would be awesome… To answer your question, yes I hear it opening and closing. I can upload a pretty specific diagram and what I’m trying to accomplish if it helps any. I’d be interested in seeing what the outcome of your testing is and what your wiring is like. Thanks!

Ok, So here is what I drew up in paint really quick. Don’t tease, its pretty bad… but I think it gives you an idea of what I’m trying to do.

So we just built this house and the electrician decided (and I thought was a good idea) to use a photocell outside to automatically turn the outside lights and stair tread lights on when it gets dark. Problem is, I haven’t found a photocell that works reliably enough for me.

I had good luck with other Z-wave devices so I went with the LFM-20.

This is a dedicated circuit from the service panel.
The 14-2 wiring goes from the panel to a double gang box in a coat closet where 2 basic single pole override switches are. Ideally, these are always in the “on” positions unless we go out of town or something like that and we don’t want them to turn on.

The wiring for the lights come into these boxes as well. All 14-2 wiring with ground.

He ran a single 14-3 wired (with red) to the outside box that is on the exterior of the house… this is where the photocell was supposed to be…

When I flip the breaker on, the black wire on the outside j-box is hot. This is where I’d like the Z-wave device to come into play. I’d like LFM-20 to tuck inside this outside box with a weather resistant blank cover on it. Then I never have to mess with the outside box any more.

The load would come in on black, go out on red and back to my override switches.

Confusing I know. Take a look at the picture…

For now I just have the black wire nutted to the red wire that way my override switches hidden in my closet can still manually control these lights.


P.S. If it comes down to it I will just take the outside box out of the equation and buy 2 traditional Z-Switches and wire them where my override switches are, cap off the wiring that goes to the outside box and call it day. It will cost me more though. :smile:

PIC: http://s3.postimg.org/vna0ns2xf/Untitled.jpg

Please see this thread for a similar setup and my suggestions on how to wire it:

Basically you need to need to combine the black hot wire to the LMF-20 black AND one blue wire. Then connect the red wire to the other blue wire and of course white to white and green ground to ground.

Hi ritchie,
That makes perfect sense… I do believe I tried this though the other evening. It seemed like the switch wouldn’t interrupt power to the other blue wire when I had the relay turned off. I could hear the relay clicking off and on though. I was just using a regular hot wire tester and it was going nuts. I’ll try this again though because perhaps it was working as intended and my tester could have been picking up hot from the feed coming in.

One other thing caught my attention in the post you linked… The poster says he had to change the mode of the FS20-Z or in my case the re-branded LFM-20 to “Z-Wave Switch”… Do I need to do this? I suppose it could be the source of the issue I’m seeing with it not switching off. In the ST App is showed it as an On/Off outlet.

Believe you are correct and you should try changing it to a switch instead. I am only using one for my garage door opener and have not tried it as a switch. That could definitely be the issue as well, but the proposed wiring should do the trick for you.


Since you’re close to other energized lines I would only trust a VOM as a tester. Sounds like you might be using something else. If you don’t have one maybe connect the lights as described above and see if it works. Also, if you hear it clicking when you send a command from smartthings then the device type you’re using most likely works fine. There should also be a small manual button in the middle if you need to force it off and on for testing.

I forgot to mention based on your wiring diagram you should wire nut these 3 wires to together, black input, black wire from LFM and one blue from LFM. The remaining blue wire will wire nut to the red. Obviously white to white. Then you would need the manual switch left in the on position unless you pull it out and bypass. Good luck.

Thank you Matt and Ritchie, it works after I wired it up like you said and tested it via the lights. Works like a champ. I really appreciate it!

Great to hear you got it working!