I needed a very basic way to tell if the power has gone out for the outlet to my garage freezer. It is plugged into a GFCI, so if it trips, I’d like to know before food spoils. While you can get GFCI outlets with audible alarms, I’d rather be notified in some way.
Here’s what I came up with:
I used a 5v DC power supply, connected to the input of a 5V Relay Module, with a jumper from the + terminal to the input terminal on the relay. This causes the relay to activate when the power is applied.
On the other side of the relay, connected the normally open terminals to the external input terminals on a QS1117-840 IQ Door/Window Mini Extended sensor.
I have the sensor joined to my IQ 4 panel as “Garage Freezer Power Status” in Group 25 (Local Safety Sensor)*. (see note below). I then setup notifications in alarm.com to signal me when this sensor changes state.
Operation
So when the power fails on the 5v supply, the relay module opens, which in turn opens the sensor. Then, I have the IQ Panel set to notify me whenever that sensor opens and report it as a power failure.
Recovery
When the power is re-applied, the relay closes, the sensor closes and the IQ panel announces the closure and sends me another notification.
Implementation
I simply plugged the 5v supply into the same outlet with the freezer. I also purchased a small project box and connectors to make it all look neat.
Parts List:
- Power Supply: Amazon.com
- Relay: Amazon.com
- Door Sensor: IQ Mini Door/Window Extended Sensor - Qolsys QS1137-840 - Surety
Variations:
Any other sensor - z-wave, zigbee, etc. That IQ Door sensor could easily be any other type of contact sensor - a Shelly i4, a switch input on a Zooz Z-Wave relay, etc. So this basic solution should work in a variety of scenarios, and can even land in your home automation environment instead of your alarm (home assistant, hubitat, smartthings, etc.).
Almost any alarm panel. I plan on implementing this to monitor the power to my sump pump outlet as well, and in that case I’m just bringing the 5v supply right into my alarm can where my takeover module is. That way I can place the relay in the box and just direct wire it into an open spot on my IQ 16-F Hardwire. The big benefit of this is that I won’t have to go in my crawlspace to replace the sensor battery!
I suppose if I had another panel, like a Vista 20P, etc I could do something similar.
Some Pictures
Here’s an ugly picture of the module in a disassembled state while I was still building it on the bench. When I have time I’ll post the final version fully assembled in its project box with the wiring sorted better.
(For those of you with bionic vision, you will notice this picture is a 12v relay not the 5v. This pic is of an earlier prototype that is exactly as above, only 12v. Considering this use case, I thought the lower the voltage the better for the long run.)
Note on the Sensor config in the IQ panel.
I played with several group options for this and while I settled for now on Door/Window Group 25, I’m considering changing this to Heat, Water or Freeze sensor type in Group 25 instead. Those sensor types constantly vocalize on the panel and require a human to acknowledge it to silence. Could be handy in certain circumstances depending on how urgent the power being out really is for your use case. For mine I think the alert via ADC is probably enough.