Monoprice 11990 Dual Relay In Wall - 3-Way Wiring Possible?

I have searched a lot on this one, can’t be the only person in this situation. In the box I want to put this in-wall relay, I have a single-pole switch which is working great, but the second switch is a 3-way switch. It has the hot, the load, and an additional traveler wire.

Relay Switch 1 is wired to the single-pole and working great, reporting and toggling.

Switch 2, I hear the “click” but it’s not responding – Plus, the additional rub is that it’s also seemed to cause the other switch across the room to not work unless the switch is in a certain position. So I know the wiring is wrong, but maybe, not even possible.

I haven’t touched the hot as I know that wire doesn’t connect to either of the remaining green and yellow wires for Switch 2, but I have tried both the load and the traveler wire and neither seem to work. I hear the relay “click” when I send the switch 2 toggle command but it’s not doing anything to the light itself.

This may just not be possible – Would love to know for sure though. Why are 3-way switches such a nightmare in z-wave world? Sigh.

According to the manual page 3 has an example wiring diagram. It sounds like your remote switch is cutting power to the whole unit.

Thanks – It looks like that diagram sort of assumes you have 2 single-pole switches in your wallbox, not a 3-way.

I assume the only gang box that this will work in would be the one where the switch is before the load/light. If it’s the gang box where the power is coming in (hot), not the box where the wire is going to the fixture (load) I am out of luck, right?

If it was previously wired as 3 way, this won’t work in the gang box. How it runs in the wall to the second box will make the difference.
If it is wired this way, Good luck, there aren’t enough wires from the first switch.

If it is wired like this, you wire the main module to the box on the left, connecting the module as follows:
Module wire Green => Red wire
Module Wire Blue => Wall Switch (one of the brass connections if re-using the current switches)
Switch Silver connection => White common connection
Module Red => Black wire to the fixture
Module Black wire => Common Black
Black from remote switch => Common Black
White from Module => Common White
White from fixture => Common White

Basically, connect all of the white wires together. Isolate the White from both switches (Cap) Connect the Black wires from each leg as labeled. (Switch 1 black to Module Green, S2 Red to module Blue, S2 Black to Clack, Lamp Black to module Red) Black mains to black module.

Thanks for all the help folks.

I just realized something else in trying to get this to work. The first switch, which I thought was at least working (single pole) is a Lutron diva slide dimmer (decora switch with small slider to set brightness). Get this - The module seems to make the Diva ignore the slider switch position effectively turning it into a simple on-off switch with no dimming at all. And it’s a manual slider even, not the digital dim which I knew wouldn’t work.

Looks like these are really only useful in a wall box where you want no dimming and just single pole single location on-off switches. Which limits their versatility to me.

I’ll just have to save up for true dimming 3 way compliant switches and companion switches for all these wall boxes.

This one is tricky. First, this particular device is not a dimmer. There are some in wall micros that can do dimming, it’s just this isn’t one of them.

Next, as @Ac7ss said what you can do is going to depend very much on what your existing wiring is. You need to map the circuits. In particular, you need to know exactly where the second master is that this auxiliary talks too. That’s going to make a big difference in what’s possible.

The current set up

First, let me understand the situation. You’re saying you have a double gang box and it has two switches in it. One switch controls the load to fixture A. The second switch is an auxiliary to a third switch, a master, which controls the load to an entirely separate fixture B.

Is that correct? If so, the information you were previously given in this thread may not apply. It all comes down to where that second master is.

The Monoprice dual relay

This relay is designed to control two separate devices on the same circuit (not two separate circuits). This is why there is only one live and one neutral shown in the diagram. The most common set up for this would be lights and an on/off fan in a bathroom. But it could also be lights and a coffee maker in the kitchen.

It is not intended to act as part of a three-way to another circuit. (edited to add as @Navat604 ( who is an electrician) points out below, it may be possible to use one of the two endpoints on this device as part of a three-way, but they all have to be using the same line hot. It’s not just that this is a dual radio device for two separate circuits.)

Zwave threeways

Although zwave threeways can seem complicated at first, it helps if you just don’t think about the nonnetworked wiring at all. It’s just going to work differently.

For a typical three-way set up in zwave you’re going to have the master switch which controls the load to the light/appliance. The auxiliary switch is going to do nothing except send a message to the master switch telling it what to do. That’s it. It will not control any load. This is why many manufacturers call the auxiliary a “remote” or a “dummy.” It just tells the master what to do.

Match the master with an auxiliary specifically designed to work with that model

You always have to match the auxiliary to a master it was specifically designed to communicate with. So in a situation like yours, you’re going to have to replace a third switch as well, the master that the auxiliary communicates with. You always have to replace all of the switches in a three-way/four-way set up when you convert to zwave.

auxiliaries to a Z wave Master can communicate in two different ways

Auxiliaries for a Z wave Master will usually communicate with that master in one of two different ways. Different manufacturers use different methods.

The first method, and the one that you tend to see in high-end switches, is for the auxiliary to communicate wirelessly. It might send a message to the master which then sends a message to the hub, or it might communicate directly to the master. There will be no physical traveler wires used.

This method has the advantage that the master and the auxiliary can be on two completely different circuits, so you can add the auxiliary anywhere that it’s convenient. Also, you will be able to have dimming from the auxiliary if desired. You will see this method in Leviton and Cooper switches, for example. Again, you have to get the auxiliary that matches the master. ( this is also the method that Lutron switches typically use , even though they are not using zwave).

The second common method uses an actual traveler wire between the auxiliary and the master. You still have to use an auxiliary which is designed for use with that master. And the auxiliary still will not control the load to the end device. But there is a physical traveler wire. GE switches use this method.

Why most zwave switches need a neutral

Regardless of the method used for communication between the auxiliary and the master, both the auxiliary and the master have to always have power even when the switch appears to be off. This is so they can communicate to the master. In most cases, this power will come from the neutral.

So, the simplest way to do a three-way with Z wave switches is to get a set specifically designed to work together and which does not require physical traveler wires, and then install them in switch boxes that have a neutral available for each switch. If you do that, it really is pretty easy, in fact it’s easier than many ways of doing a non-networked 3 way because you don’t have to have them on the same circuit and you don’t have to worry about traveler wires.

back to your set up: one master switch for fixture A and an auxiliary for fixture B in a double gang box

In your specific case, as long as there is a neutral in the switchbox available to both of the two switches, I would just put in a master switch for the fixture which is controlled by the master that is already there, and then I would replace the Lutron auxiliary with an auxiliary which is matched to a Z wave Master that is controlling Fixture B, whatever it is. Note that you have to replace that second master as well as any other auxiliary switches tied to it. And then you should be all set.

I would save the relay device that you already have for a situation where you want to control two different end devices on the same circuit. That’s what it is intended for. You will still need a neutral for it, because the neutral is what powers the radio so the relay can hear the next “on command” even when it appears to be off.

If for whatever reason you want to use a relay there, you can do it, but you will be easier to use two separate relays. Most people would use an aeotec micro relay for this.

These can be wired into a three-way using Direct wires to the micro, but to be honest, I would recommend instead setting up a “virtual three-way” where the auxiliary communicates to the hub and the hub communicates to the master. You may have to do it as a virtual if in fact your Lutron auxiliary is not on the same circuit as your existing Lutron master. But in any case note that you were going to need two separate Micros: one for the master A in the box and one for the auxiliary B. And unless you use direct wiring you’re going to also need a third device for master B.

@Navat604 or @dalec or one of the other wiring experts can check this post for me to make sure I didn’t say something backwards or whatever. (I know the devices, but I leave the wiring to the electricians. :sunglasses: )

The wiring experts may also be able to say whether you can use your auxiliary B with the second endpoint of your current relay. there might also be a way to just get access to the radio.

Anyway, I hope that helps clear up some of the confusion. Since the existing auxiliary is a lutron device, it may have been communicating wirelessly to another Lutron master. You will still need to replace the second master as well as the new auxiliary so that they will be able to communicate to each other. You can’t mix-and-match even if they’re both network switches.

avoiding headaches

You probably already know the following, but just in case:

One) in the US, code does not mandate any particular wire color. So people can and do use any color for any purpose. So you can’t just go by wire colors, you have to actually test every segment of every circuit to know what it’s doing.

  1. always take before pictures, including of the backs of the switch is where the wires attached to the screws, and label each wire, so you’ll be able to put things back if you run into any problems.
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As far as the Lutron switch being set to be just on/off rather than dimming, that’s a safety feature of Lutron devices which allows them to be used with fluorescent tubes and other fixtures which don’t support dimming. Sometimes people will set them that way by accident ( it’s usually a button press pattern) and then don’t know how to set them back. Or sometimes the installer sets the switch that way because that’s the only model that they have but they need to install it with a fixture where dimming wouldn’t work.

Before we go further. See if you can answer @Ac7ss and @JDRoberts questions about your wiring configuration. You could use the Monoprice dual relay to control a single pole circuit and a 3 ways circuit but only if your light circuits share the same line hot wire and your 3 ways circuit is also the same wiring configuration as described by @Ac7ss above.
You are right about no dimming capability. This is a dual on/off relay. That’s why it’s called relay module. Aeon or Fibaro do make dimmer in wall module.
Don’t take this the wrong way and I am only trying to help but I would suggest you should learn a little about 3 ways wiring first before tackling this because it could be very frustrating if you are guessing also dangerous.

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In that case, the second endpoint on the relay would become the master to the three-way, right? And the existing master B (which is in a second switchbox) would probably become a wireless auxiliary for the new master. But that will only work if the two fixtures share the same line hot.

Is there a way to use this relay device so that the second end point just gets power for the radio and could be used as a wireless auxiliary to the other master in the other switch box? Or is there just no way to wire it so it’s not controlling a load?

As @Ac7ss mentioned, really the next step is to figure out where the other master is that the Lutron aux is talking to and to map that circuit. If it’s an altogether different circuit, the solution is going to be very different.

You can use the first or second end point for the 3 ways circuit and the way the dumb 3 ways switches controlling the end point is a little different from the typical z-wave master/add-on combo. Both dumb 3 ways switches are master controlling that on/off trigger on the Monoprice relay. That’s the reason why not all 3 ways will work with this setup. All the Monoprice looking for is 110VAC for ON and 0VAC for OFF at the end point trigger.

Are you talking about having the same thing as the Linear WD500z and WT00z type of setup? You definitely could with the right wiring config. Only downside is because the Monoprice is using virtual switch for end point so ST cloud down = no control of one switch.

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Yes, that. So no association. Got it, thanks. :sunglasses:

First let me just say thank you all for taking the time to respond with help. What a great community this is.

Before we get into the 3 way discussion any further, I wanted to just make sure I wasn’t doing anything wrong with my 2-way switch. Because if this relay defeats any internal manual dimmer setting in the Diva switch, this relay is useless to me in the wallbox anyway.

I first hooked up the Lutron diva with the manual dimmer slider without the relay and verified its dimming works. Then I connected it to the relay’s red and blue wires. This switch is also the one drawing power from the relay (its black line wire is capped in with the black wire from the relay).

I took a photo but but sure how helpful it will be.

I just want to verify, the relay is defeating any attempts for the manual slider dimmer to dim the lights. It’s as if the relay just causes the light switch to ignore any manual position of the dimmer slider and will only send FULL brightness or off.

So, unless I am doing something wrong, I am taking this relay out of the wall box and not moving further with it.

I fully realize it will not control dimming via remote, but using the manual slider on the Lutron diva switch should still control the dimness of the lights outside, and it is not when I introduce the relay.

Unless I am doing this wrong…I am done with the unit since it does not support manual dimmers.

The dimmer won’t work with the 11990 relay.

It sounds like the best idea is to wire in a SH Wallswitch with dimming, such as this and wire in the remote with another remote controller, such as this.

Sorry I didn’t understand exactly what you were trying to do originally.

The way most nonnetworked dimmers work is by changing the amount of current sent to the fixture.

This relay does not send variable amounts of current. It’s either on or off.

So if you hook a dimmer switch up to this relay you will lose the dimming function. (You may also damage the dimmer switch, that’s a different issue.)

So it sounds like this relay is not going to work with what you want.

That said, I’m not sure there is a Z wave device that will allow you to use a Lutron maestro switch as the switch. Z wave dimmers are generally not analog. That is you’re not dimming them like with a rotary dial. You’re moving them through a digital range, typically 0 to 99. But sometimes just low/medium/high.

For example, the user guide for the Aeotech micro dimmer says:

We recommend that you do not use a dimmer switch, it will not dim the micro dimmer. You will be left with having to twist or pull the switch all the way across to make it turn the lights on or off.

Instead, they just recommend a momentary switch which is sort of like a doorbell button and each time you press it the light will get brighter. But that’s because you’re moving it to a new digital level.

I hope that makes sense. But if what you’re asking is if you can use a Lutron Maestro switch with a zwave micro of any kind and retain dimmer functionality at the switch, I’m pretty sure the answer is no.

The OP could certainly replace the master with another master.

I’m not sure what the idea was for that accessory switch, but that’s a dummy switch. Nonloadbearing. It can only be used with a matching Linear master. (GoControl devices are rebranded Linear’s.) The OP has to know what the master switch is and be prepared to change out both the auxiliary and its master. And in that case they would need two devices, not just one. From the product description:

Load: does not directly control a load. Another Z-Wave device is required.

It’s sometimes possible to replace a loadbearing 3 way switch with a dummy and make it all work, but only if you’re also replacing the master with a matching device. And in those cases you often need to rewire the master as well so it’s always in control of the load.

I totally agree with you guys and that I basically just have the wrong device for the job here.

What I really need to do in this gangbox is put in actual zwave switches that support dimming, and then for the 3-way one, also buy remote switches to complement its master (it’s actually got 3 switched locations which will mean buying 3 more switches to replace it, plus a 4th single-pole for the other switch). So I was trying to cheat and use a single relay to accomplish remote control, instead of buying 4 switches.

That said, I can look to see if I can repurpose this thing elsewhere, even in a single gangbox. I have an on-off switch that starts my gas fireplace. Would this be something I can use to add zwave control to that or am I getting into a whole new world of devices and confusion with gas fireplace switches?

Gas fireplace switches are an entirely different world. There are a number of project reports on those. But the very first thing you need to do is check code in your jurisdiction. In many jurisdictions it is illegal to have a remote control of a gas fireplace that operates out of line of sight. That’s why so many of the starters that you can buy nationally are limited to 20 feet of range. This is a safety issue. They don’t even want you to have a button in an upstairs bedroom that would turn on the downstairs fireplace.

It’s very important to understand that by definition any SmartThings control of a gas fireplace would violate this type of restriction because you could be sitting at your office and turn it on. You might know that you wouldn’t, but just because you can you would be in violation. And that normally voids your homeowners insurance.

You should also know that on more than one occasion members have reported in the forums that SmartThings has randomly turned on devices in their home, including, yes, gas fireplaces. People who have these devices will add additional safety features, usually something in the device itself (and therefore not dependent on SmartThings in any way) that shut itself off. Those kinds of devices cost more, but are definitely worth it. But again, even those may not be legal where you live.

You can use a quick browse list in the community – created wiki in the project section and look for fireplaces and see project reports on this. But it’s just A whole different world than lighting.

I wouldn’t suggest it if it is a standard 110 switch. If it is controlling a millivolt system, one that can be controlled by an off-the-shelf thermostat, you could attach a smart thermostat to it. (Just set the heat setting high and turn on and off heating to turn the fireplace on.) I have done this with a gas stove that I use for heating my house. But I wouldn’t just throw a smart toggle switch in it. The thermostat has a shutoff point.

All great points why I should give up that novelty – Not worth the risk!

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