So you can’t power one load with 2 relays?
I’m not an electrician so I’m sure I’m just being dumb but if load 1 and load 2 wires both provide power to one wire will it make the earth explode or something? 
I am a little confused. If you have line, load and neutral in the same box. Then it’s better to use just one relay in the dual module. This way you don’t depend so much on ST and also use the second relay for something else.
As for connecting both load wires of the module to the load wire of the light. No explosion but when ST is down. You will have one hell of a syncing problem 
Okay I have 3-way switches I’d like to control with a single relay monoprice module. Most of my switch boxes have some form of line power from other switches.
Given this knowledge, is it possible to use the wires to power a light with my two switches as well as via zwave module.
Also, in my stairwell I have 3-4-3 setup… Wondering if I can put one of these single relay modules in the 4 box somehow? Haha
No, this won’t make the world implode… but the problem is that if you put both relays to the same switch then the light will turn on if either switch OR both switches are in the on position. What you want is that if both switches are on it’ll turn off. (Otherwise it’s not 3 way. You’ll be able to turn the light on from either place, but to turn the light off you need to switch both switches to off)
Actually in my particular boxes I do have power from other switches.
Ok, @joshuairl, you need to post a photo of your boxes, or a diagram of what’s going on.
If you have it hooked up like diagram 1 (Below), the issue is that there isn’t constant power in box 2. and Box 2 is feeding the light, but constant power comes to box 1. If you do have constant power then it’s super easy to put a 3-way replay into box 2 with no special work at all.
Okay I have 3-way switches I’d like to control with a single relay monoprice module. Most of my switch boxes have some form of line power from other switches.
Given this knowledge, is it possible to use the wires to power a light with my two switches as well as via zwave module.
Yes, it’s super easy then. What you need to do is hook the relay up right before the light. (I said initially to put it in the light box, but you don’t have power there, so if you do have power in the switch box with the 3-way switch that feeds the light then it’s the same thing)
What you would do is hook the relay up between the last switch and the light.
The way a 3-way works is that if the switches are opposite of each other it sends power to the light. So as far as the light is concerned it’s a simple on/off. So just use that on/off signal for your input to the relay. As long as you have constant power there as well to power the relay.
Does that make sense?
Yep! Sorry my brain was just not able to visualize it. But I think I understand perfectly now. Haha!
Sorry guys!
The ST smart light has the ability to sync on/off with both switches. So you can tell the app with these conditions.
1st instance :When box 1 switch on. Turn box 2 switch on. Also do the same for off
2st instance : when box 2 switch on. Turn box 1 switch on. Also for off.
These will keep them in sync until you have no internet then well… you know.
Look like the 3 of us going around in circle here
FYI I’m trying this as we speak.
Here is what I’m looking at. Going to try to tap a single relay on to the center switch as an experiment.
Apparently I’m just not getting it haha
Because I wired how I thought made sense and the relay toggles the light fine but the switches aren’t doing jack now lmao… Guessing I missed something.
I have green wire of monoprice going to black screw on the switch and red monoprice going to load.
Black / blue on monoprice going to hot
And white monoprice going to neutral lol
Thinking I didn’t do it right though xD
So do I just unhook the common on the right switch and wire it between the switch and the load wire? Because I feel like when I do that all its letting me do is control with the relay but not the switches
I’m so confused now.
So this 3-wire coming from other switch… The white wire from it is bundled in the hot on this end…
What does that mean?
Man, you are just having lots of fun aren’t you?
Ok, so if I understand correctly, the relay has power, it shows up in ST.
ST can turn the light on and off, but neither switch does anything.
Is that right?
From the photo I think you have the loads mixed up. I suggest you put some tape onto the yellow and green wires. You don’t want to use those for what we are doing.
I assume the middle switch is the one you want to use, if that’s right, the blue wire should be on the switch, not the green one. The green wire isn’t used.
You’ll want to put the blue wire onto the screw on the switch where the light’s wire used to be. (Which should be the wire that the Red wire is connected to)
Again… I’m NOT an electrician. Try this at your own risk! 
I know, right?! 
Nah this is totally fun. I love this stuff. Thanks for everyone so far that has put up with me. This is truly a very great community which I was afraid to jump in to but am glad I found you guys. Very helpful so far.
Correct. Yep.
I basically wired it for monoprice instructions for 1 wall switch which got me no where so I’m willing to try any suggestions thrown at me. It’s worth the risk. I feel like more people could benefit from this info if we could nail down some specifics. If I can get enough information together about how to convert (for example) Setup A to make it work with the single relay, Setup B to work with the single relay, etc. I think it could be very powerful for newcomers that are trying to save a penny or so on a new install.
Oh, you have no idea how mixed up my brain is at this point.
I’m a programmer that’s found an entirely new appreciation for electricians. Never the less, I know I can figure this stuff out if I just force myself to make it click.
That said, if you don’t mind… could you explain your logic behind ditching the red / green wires and using the blue when instructions have told me to put blue / black directly to live?
I’m just trying to understand and get on the same page with you. Maybe if I knew what the wires on the monoprice relay represented it would help me.
Also, I don’t mind that you’re not an electrician, it’s totally worth the risk. Thanks so much for all your time so far - it’s sincerely appreciated. Just trying to push this technology forward and I think we’re breaking some new ground. The internet has not had any brave souls tackle this topic in such a thorough way and I’m happy to be at the forefront of it.
I simply cannot justify putting GE/Jasco switches and ditching the existing 3-way logic COMPLETELY. It just feels wrong. It feels like a quick patch and I’m assuming if ST goes down, my aux switches won’t work with GE, right? Never the less, I’m sure the same applies to our re-purposing of these wires too but I’m at least willing to get it working for 1/3 the cost of the GE setup.
Thanks again!
I’m willing to be the guinea pig…
I also want to understand this as well. Blue is use only with an indicator light.
I think the problem is you still don’t know what your wiring option is. I would put everything back and try figuring that out first otherwise you will go nuts.
Here are some people conversing as well about wiring but they aren’t specifying what they are trying to do.
Well I’m not sure but do you know why the white wire in the 3-wire ( with ground ) would go into the hot bundle with the black wires?
Color wire in a 3 ways doesn’t mean much. It could be anything. Try finding line, load and neutral first. Best thing to do is looking at the wiring drawing options and pick the one that’s close then ake out your meter and start measuring.
Oh I already have those bundles identified. Just not sure what to do from there… lol
Ok, so it’s really confusing when talking about the colours because there are the relay wires and the house wires both have red, black and whilte. When I said the ‘red’ wire I was talking about the red house wire, not the red wire from the Monoprice relay…
That said, if you don’t mind… could you explain your logic behind ditching the red / green wires and using the blue when instructions have told me to put blue / black directly to live?
You are ditching the green and yellow relay wires, those are for the second circuit. Right now you are only wanting to use switch 1 and load 1. All of the rest of the Monoprice wires will continue to be used.
Monoprice has their manual online. That gives a drawing of what the wires are.
At the end of the day you’ll want to have the Monoprice wires hooked up like this:
- Power the relay with constant power (Black and white)
------ Assuming you are using circuit 1: - Put the light onto the relay with the red wire
- Use the blue wire for the physical switch.
Think of your relay as a ‘neutral’ device for the switches, and a ‘hot’ device for the loads.
So the wire that used to connect the light to the neutral power gets disconnected and goes to the red relay wire
The wire that used to connect to the neutral side of the switch now goes to the blue relay wire.
Perhaps these diagrams will help. The first is what you said you have. And then the second is adding in the relay. You’ll notice how you need to have an extra black and white constant source of power inside the second box in order to power the relay. You’ve said you have this, but many people may not.
@Snakedog116 Thanks for the thorough explanation! However, I guess my confusion came from the fact that I was referring to the single relay monoprice device not the dual relay device. But I’d imagine the same logic applies? just different wire colors?