The ZEN55 DC Signal Sensor is a unique Z-Wave device that can read analog signals from interconnected smoke and CO alarms as well as control a connected 120 V load. Please remember that the DC Signal Sensor is NOT a security alarm component and the device is NOT part of a life-safety system. Check local regulations before installing.

Here are the most common use cases for this device:

• Analog interconnected smoke detector: on the input side, the device will report a smoke alert to the hub via Z-Wave if your analog detector triggers it with the low-voltage signal alert. The device has been successfully tested with the most popular brands including First Alert, Kidde, and BRK.
• Analog interconnected CO detector: on the input side, the device will also report a CO alert (a different type of signal) to the hub via Z-Wave if your analog CO detector goes off. The device has been successfully tested with the most popular brands including First Alert, Kidde, and BRK.
• 120 V light: on the output side, the device is a 15 A relay which can control a light fixture either separately of the alarm inputs or directly tied to them to signal danger visually.
• 120 V alarm siren: on the output side, you can connect a 120 V powered analog siren to be triggered whenever the alarm goes off, as well as based on any other conditions or connected devices in your hub. You're just turning an analog siren into a smart siren with this little relay!

Watch the DC Signal Sensor In Action, including installation tips and automation on Home Assistant:

And here are some examples of scenarios where the ZEN55 DC Signal Sensor will NOT work:

• Analog smoke and CO detectors that are not interconnected: you can still technically use the ZEN55 with this type of detectors but you will need to attach one ZEN55 per connection which will substantially increase the cost and time you'll spend on this project.
• Battery powered smoke and CO detectors: you always need to have a 120 V power source to install the ZEN55 device (it needs constant power for the Z-Wave radio).
• If you need a life-safety system device: the ZEN55 is not certified for life-safety applications.
• In an electrical box where you do not have 120 V (line and neutral) available.
• If your Z-Wave hub does not support notification type devices such as the ZEN55 (check Z-Wave compatibility for this product here).
• If you need to know which detector in the house went on first: since the detectors are interconnected, you only need one ZEN55 device that will get triggered if any of the smoke or CO detectors send an alarm signal. You will not know which room first triggered the detectors, all you'll know is that the alarm went off.

If you have another use case for this device you would like to share with us, please do and we'll add it to the list!