Power failure warning

Configuration
1

Hi everyone, I’m trying to create an automation but I can’t do it as I would like.

I have a technical room where I have these 4 devices
(Boiler, refrigerator, freezer and washing machine).

Being a dedicated power line, I put a shelly EM upstream to monitor the current draw of that power line.

Since it is a room outside the home, I wanted to make an automation that would notify me in the event of a power failure.

I tried to set an alert when the absorption was equal to 0watt for 120 seconds.
This summer it worked well, but now that it is cooler it often tells me that there is no power.
So I investigated and I realized that this summer it was working properly because the refrigerator or freezer were almost always in operation in the heat.
Now that the cooler and the freezer work less when it is cool, it often signals me that I am consuming 0Watt so there is no electricity.

How can I make an automation that signals me the actual lack of current?

2

I don’t know, how the shelly works, but what I think as an electrician is, that you need a sensor, which does not look at the current draw, but Voltage presence. I hope for you, it is possible with this Shelly.

Either Voltage present on/off or measurement - Voltage drops under, let’s say, 20 V => trigger.

3

Thank you Bebe,
on the native shelly app there is both the signaling of the absorbed power and the current voltage.
Unfortunately there is no automation that monitors the voltage.
At this point I believe that the only possibility is in home assistant.

4

Yes, so just create an automation to send alert, when Voltage drops under 40V for 120s. :wink: