ZEN51 Dry Contact Relay FAQ's

ZEN51 Dry Contact Relay FAQs

Frequently Asked Questions About the ZEN51 Dry Contact Relay

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ZEN51 Dry Contact Relay

INSTALLATION QUESTIONS

Can the ZEN51 be installed outdoors?

No. The ZEN51 is rated for indoor use only.

What is the operating temperature of the ZEN51?

32-104° F (0-40° C)

What are the dimensions of the ZEN51? How big is the device?

1.5" tall, 1.4" wide, 0.7" deep

Can I fit multiple ZEN51 in the same switch box?

If your switch box is deep enough and the box is not overcrowded with wires then you should be able to fit more than one ZEN51 unit in the same switch box.

Can the ZEN51 be used in 12-24V or 240V installations?

The relay part IN and OUT can be used as dry contact, or take 12-24V AC or 120-240V AC. But remember that the ZEN51 device itself needs to be powered with 120V AC and the switch input also requires 120 V to work. If you're looking for a dry contact relay activated by a dry contact input, we recommend looking into the ZEN16 or ZEN17 models instead.

Is the ZEN51 CSA approved?

While Zooz devices don't have any Canada-specific certifications, our devices are ETL-certified and are fully compliant with North American safety standards.

How do I install the ZEN51?

Your ZEN51 relay should come with a manual containing the most common single pole set-up.
3-Way Wiring Diagrams for the ZEN51 Dry Contact Relay
How To Set Up the Zooz | Kidde DIY Smart Smoke Alarm Kit (alternatively, you can use the ZEN55 without a Kidde module)
Installation Tips and Tricks

How Can I Identify the Wiring For My ZEN51?

Your ZEN51 comes with lifetime tech support and we're happy to help identify the wiring in your set-up and provide custom wiring instructions, free of charge. However, our techs are not magicians, mind readers, or telepaths with the ability to verify wiring without clear images from each switch box involved in your set-up. Please review the requirements in this article before submitting your images and wiring diagram request to Zooz support.

What kind of wall switch can I use with the ZEN51?

The ZEN51 can be directly connected to a simple on/off mechanical switch (without any LED indicators or illuminated elements) or a momentary switch like the ZAC99 momentary switch.
How does it work with a mechanical on/off switch? A mechanical on/off switch will turn the light on and off.
- Note that if you turn the light on with a mechanical switch (toggle is up) and then turn it off via Z-Wave, the toggle switch will still be up. You'll need to toggle it down and then up again to turn the light on the next time. You can modify the behavior by changing the value of parameter 7 in the advanced settings to 0 for the switch to control the light on/off whenever it's toggled (so you could turn the light off by toggling up or turn it on by toggling down).
How does it work with a momentary switch? First, you'll need to change the value of parameter 7 in the advanced settings to 1 for the ZEN51 to be controlled correctly with a momentary switch like the ZAC99. The ZAC99 momentary switch is a one-paddle switch that works in a sequence, similar to a garbage disposal switch. Anytime you tap it, the switch will change the status of the light (turn it on or off).
- Note that wiring the ZEN51 relay with momentary switches in 3-way and 4-way installations is different than with mechanical toggle switches so always include that detail when requesting assistance with wiring your relay.
How about a smart switch? While you can never connect an electronic or smart switch to the ZEN51 electrically through a wired connections, there is an alternative. If your local regulations allow it, you can skip the direct electrical switch connection and control the ZEN51 remotely using any Zooz smart switch or remote instead. You would program them with multi-tap scene control triggers or direct association if you hub supports these advanced features.

Can I use the ZEN51 with a dimmer?

No, the ZEN51 provides on/off control only and needs to be connected to regular on/off switch (no LED indicators or illuminated paddles).

Can I use the ZEN51 with a momentary switch?

The ZEN51 can be installed with the ZAC99 Momentary Switch; you would need to change the advanced settings for the external switch type. Please change Parameter 7 to value 1 to use the ZEN51 with a momentary switch.
A momentary switch is a type of push button that only works while being pressed and held. Here is how the ZAC99 behaves: Only the top part of the switch is clicked to use it. If you click the switch once, it will turn on. It does not have any Z-Wave capabilities.
Note that wiring the ZEN51 relay with momentary switches in 3-way and 4-way installations is different than with mechanical toggle switches so always include that detail when requesting assistance with wiring your relay.

What is the difference between the "toggle switch" and "toggle switch with fixed actions" in the switch settings (parameter 7)?

The "toggle switch" setting will allow the wall switch connected to the ZEN51 to change the status of the lights anytime the switch is toggled (up or down), similar to a toggle switch behavior in a 3-way installation where there are 2 points of control and sometimes toggling the switch DOWN will turn the lights ON.
The "toggle switch with fixed actions" setting will allow the wall switch connected to the ZEN51 only according to "up = on / down = off" rule so the toggle switch would always need to be toggled UP to turn the light ON and toggled DOWN to turn the light OFF. So if the lights is turned on via Z-Wave but the toggle switch is currently toggled down, you will need to toggle the switch up and down again to turn the lights off (rather than just toggling it up to turn them off like in the "toggle switch" setting).

Can I install the ZEN51 without a wall switch?

The ZEN51 can be wired without a physical switch. You would follow the diagram in the manual, just with the S pigtail (that go to the switch) capped.
Please ensure you have verified if it's acceptable to have a 120 V fixture without a wall control for emergency shut-off with your local regulations. In most places this kind of set-up is not up to code.
You will also want to ensure the load is within the specs for the ZEN51: 960W incandescent, 150W LED bulbs, 10A resistive, 1/2 HP fan motors

Can I use the ZEN51 in a 4-way set-up?

Yes, but special wiring is required. We're happy to provide a custom wiring diagram free of charge!
Please make sure your product is registered to receive custom wiring support from our technicians.
Please review the wiring images checklist requirements found here before reaching out to support to expedite your wiring diagram request.

Can I use smart bulbs with the ZEN51?

Yes. The ZEN51 has a special Smart Bulb Mode setting, which disables the manual and/or Z-Wave control for the ZEN51. Always turn the ZEN51 on first before changing this setting. This is important because otherwise you would be cutting power to the smart bulbs and not be able to control them wirelessly / remotely.

What is the warranty coverage for the ZEN51?

Zooz 500 series devices are covered by a 12 month warranty. Zooz 700 and 800 series devices are covered by a standard 1-year warranty and by an extended 5-year warranty if registered within 30 days of purchase. Please register your device here and review the full warranty policy here.

Where can I find the device manual for the ZEN51?

Manual for Zooz 700 Series Z-Wave Plus Dry Contact Relay ZEN51 (PDF)

PRODUCT FUNCTIONALITY QUESTIONS

What security level does the ZEN51 pair to my controller or hub with?

The highest level of security the ZEN51 supports is S2 Authenticated.

Will the ZEN51 act as a signal repeater for other Z-Wave devices in my network?

Yes, it will act as a repeater in a traditional mesh because the ZEN51 is constantly powered. Your Z-Wave hub decides which devices to use to reach other Z-Wave devices. Any non-battery powered Z-Wave device will act as a signal repeater; it would be up to your hub whether or not it will be used in a communication route.
If your hub supports Z-Wave Long Range and you have the latest LR version of the ZEN51 device, you can add it to your network as a Long Range device which means it will communicate with the hub directly at a much greater range. But it also means it will not participate in your Z-Wave mesh and will not act as a signal repeater or range extender since Z-Wave Long Range is a star topology type network.

What kind of load is the ZEN51 rated for? What is its maximum rating?

960W incandescent, 150W LED bulbs, 10A resistive, 1/2 HP fan motors.

Are the ZEN51 leads copper or aluminum?

They are COPPER stranded wires, tinned with an antioxidant layer.

What does each wire on the ZEN51 do?

S : The yellow wire is the switch input pigtail, which would connect to the switch for manual on/off control. Note that the input requires 120V for this device.
OUT : The red wire is the outcoming connection for the load to close the circuit and trigger the connected load.
IN : The blue wire is the incoming connection for the load to provide power from either 120 V or another power source, or to remain dry (without Voltage) for dry contact applications. In standard 120 V use cases like light or fan control, you would connect this pigtail to the 120 V power source as shown in the primary diagram in the product manual.
L : The black wire is Line, which is connected to the power / line bundle in your switch box to power the ZEN51.
N : The white wire is Neutral. It needs to be connected to the neutral wire bundle in your switch box.

What is the impulse mode (parameter 7 value 3) and the impulse duration (parameter 11) in the advanced settings used for?

Parameter 11 should only be used if you have been instructed to set Parameter 7 to value 3. It is a specific design which allows the ZEN51 to be installed in situations where load and line are in separate boxes as in option 2 in the 3-way options.
The impulse mode duration (parameter 11) is in milliseconds and we chose 10 seconds as the default. The value here will depend on the length of the wire; this is adjustable in case customers have issues with a missed toggle or switch not working at all in impulse mode due to the duration of the signal in the line. However, we have found that this setting is rarely changed.

Is the ZEN51 truly a dry contact relay or something electronically switched?

The ZEN51 has a dry contact output only, so while it can be used to control a dry contact on the output, the input (switch side) requires 120V. The ZEN51 needs a 120VAC (neutral and live) to be connected to the L and N pigtails. The IN and OUT pigtails are true dry contact connections, separated from 120VAC.

Can I include or exclude the ZEN51 to/from the hub using the connected mechanical switch (rather than the Z-Wave button)?

Yes. The external switch connected to ZEN51 has to be very quickly flipped 3 times from off to on, so: "up-down, up-down, up-down" to put the device in inclusion / exclusion mode. Check out the video linked here to show you how this process works!

Could I use the ZEN51 to monitor a standard doorbell and power it with a 24V standard doorbell transformer?

No. The ZEN51 Dry Contact Relay needs to be powered by 120V so it would not be a good fit for a doorbell set-up. Only the ZEN16 or ZEN17 models can be powered by 12-24 V so we would recommend them for this application instead.

UNIQUE SET-UP QUESTIONS

To wire the ZEN51 to the Kidde Module

Kiddie Black Wire (Hot) AND Kiddie Blue wire (Common) with ZEN51 Black pigtail “L” AND to Existing Smoke Alarm black wire Hot
Kiddie White Wire (Neutral) with ZEN51 White pigtail “N” AND to Existing Smoke Alarm white wire Neutral
Kiddie Red Wire (Interconnect) with Existing Smoke Alarm Interconnect wire red/orange
Kiddie Orange Wire (Normally Open Contact) to ZEN51 yellow pigtail “S”
ZEN51 “IN” and “OUT” – not used, capped. The rest of the wires from the Kiddie module – not used, capped.

NOTE: Instead of connecting the ZEN51 to a Kidde module, we recommend purchasing the ZEN55 DC Signal Sensor device which doesn't require any additional hardware for extended functionality.

Z-WAVE QUESTIONS

Do I need a Z-Wave hub to buy the ZEN51?

No. With the ZEN51 installed, you can still control the connected load with the wall switch so you can install it without having a Z-Wave hub; however, to control the device remotely and access the advanced features, you would need a Z-Wave hub. The ZEN51 communicates via Z-Wave and would require a hub to allow you to control it remotely.
To control any of our Z-Wave devices remotely through your smart phone, you'll need a compatible Z-Wave hub. These devices require a central controller that communicates with them and sends commands. Once you have a controller, you would download that controller's dedicated app on your phone and control your connected devices through that app.

Can I include or exclude the ZEN51 to/from the hub using the connected mechanical switch (rather than the Z-Wave button)?

Yes. The external switch connected to ZEN51 has to be very quickly flipped 3 times from off to on, so: "up-down, up-down, up-down" to put the device in inclusion / exclusion mode.

Will I still be able to control the ZEN51 or connected load if my Z-Wave hub is down or offline?

The ZEN51 simply adds Z-Wave control to your existing light switch, so you will have manual control of the connected load from the wall switch. You won't be able to control the load via the ZEN51 through your Z-Wave hub.

Is the ZEN51 compatible with my hub?

You can find a list of compatible hubs for a given device under the Works With section on the product's page. Here is the list of hubs compatible with the ZEN51.

Will the ZEN51 work with my alarm panel?

Alarm panels like Alarm.com will typically only support single switches, door locks, select thermostats, and any authorized items on their list. We would recommend reaching out to your alarm panel company to verify compatibility and to get the latest on any device integrations they may be working on.
The ZEN51 should pair as an on/off device, but you would not have access to the advanced functionality. It would be up to your alarm panel to integrate the ZEN51, as it follows Z-Wave protocol and has been Z-Wave certified. There is nothing we can change on our end to have the Dry Contact Relay be recognized correctly; Alarm.com would have to support the integration. Read more about alarm panel compatibility here.

Can I connect the ZEN51 directly to my Amazon Alexa, Google Home, or other smart speaker?

No. Smart speakers like Alexa or Google are not equipped with a Z-Wave chip and are not Z-Wave gateway controllers.
Smart speakers are integrated with certain Z-Wave hubs, like the Z-Box Hub, SmartThings or Hubitat, which is how you can have voice control of your Z-Wave devices from your smart speakers.
Without a compatible Z-Wave hub, no Z-Wave products will function correctly with Alexa or Google alone.

Where do I find all of my ZEN51's advanced settings?

ZEN51 Dry Contact Relay Advanced Settings

How do I add the ZEN51 to my Z-Wave hub?

How can I tell what firmware my ZEN51 is running on?

The firmware that your ZEN51 is shipped with should be printed on the back of the device where the model specifications are. If your hub supports and properly integrates the device, you should also see the firmware listed in your Z-Wave interface.
Firmware that is listed as 1.01 (or any other value with a 0 in the middle) in the ZEN51's change log may display as 1.1 in your hub.

How do I update the firmware of my ZEN51?

Some Z-Wave hubs have a built-in firmware updater that you can use. Otherwise, we recommend using the PC Controller tool on the Simplicity Studio Software as described here. You can access the firmware files here.

How long does the update take? How do I know when it's finished?

Firmware updates should usually take anywhere from 5 to 15 minutes depending on connection quality and how much information needs to actually be updated on a given device.
- If it is taking longer than that, please try to bring the hub / controller closer to the device that is being updated.

Where can I find the history of changes and firmware updates for the ZEN51?

ZEN51 Dry Contact Relay Change Log

What series Z-Wave chip does the ZEN51 use?

The ZEN51 uses a 700 series Z-Wave chip and the latest version is Z-Wave Long Range enabled.

Is the ZEN51 available in other Z-Wave frequencies?

The ZEN51 is currently available in 908.42 MHz (US, CA, MX) and 868.42 MHz (EU) frequencies.

Check out the Zooz Knowledge Base for free support articles about the ZEN51 Dry Contact Relay (and all of our devices)! If you can't find your answer there, reach out to us!