I made this for every outlet and smart plug but some with different values. Just checked how to voltage is reported on them. Notification works as I tested it, but I wouldnt go poke around some wires for, you, obvious reason. 
I will let this to see will something happen in a week or so. Maybe I will have some voltage drop or voltage high beyond those values. I can check it in history to see was there any.
Daniel,
Do you think this script will be confused by fluctuations in delivery supply. My supply is in a rural area and voltage fluctuates between 230 and 250?
Pat
It not a script. It automaton. As i checked online 10 % of the fluctuation should be acceptable.
I might give it a whirl given my fluctuations.
I check this online on a sites like this. It would be nice if someone who is actually electrician or electrical engineer can give us more info on that or just verify that numbers are correct.
i’m in Australia. We have weird electrical distribution sometimes
Voltage is the least interesting item to track. Voltage is not dependent on your equipment, it is whatever the power company feeds you.
Watts or Amps would be the better measure of the load.
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The most hungry appliance in the house is washing machine using max 10.45 amps in running cycle. So, if smart outlet or switch is rated on 16 amps probably to be on a safe side it would be nice to create automation that will cut down electricity if load exceed 12 amps or 2640 watts ( calculate based on 220v ) as nothing in the house doesn’t need nearly that much load.
Power meters are able to measure power without taking a (wrong) static voltage into account. They measure it continously as well as the amperage and the power factor to be able to provide real power.
One thing would be indeeed interesting, the power usage from @JoFranke’s blug just before it smoldered away.
By the way: The plastic used in that sonoff plus looks like it is not flammable like the gira wall socket plastic.
I’m going with current in amps for an automation.
And I have question. I installed smart outlet on a place of dumb outlet in kitchen. That dumb outlet was for some reason burned out. Electrician repair it and install new dumb outlet. It is not used much but i noticed some odd behavior. From time to time this outlet show voltage drop on 0 volts.
Neither one of other outlets or smart plugs are doing that.
Amps are probably best if you have it. I’ve seen seen some plugs only give watts without amps.
Use the products as designed.
Install them correctly.
Use them at no more than 75% of the rated power.
Since the manufacturer has absolutely no control of how the user uses the product, there is not likely any liability to assign.
One melted socket out of how many thousands is not a class-action.
How would you or any jury know if the device plugged into the socket is not the cause?
As I’ve said in the past, I did melt down a Sonoff Basic a few years ago because I installed it (incorrectly) using 14 gauge solid copper wire. It was entirely my fault.
Typically just a limitation/bug in the firmware running on the plug…
OK I created some simple automation for everything. It should shut down outlet or plug if current load is over 75 % of rated outlet or plug power.
alias: Android TV smart plug overload protection
description: ""
trigger:
- type: current
platform: device
device_id: 6a1c54efc9f052e2cd209e055f635843
entity_id: 93bc8790d6b45c2925e02b1b828e3dad
domain: sensor
above: 7.5
condition: []
action:
- service: switch.turn_off
data: {}
target:
entity_id: switch.android_tv_smart_plug
- service: telegram_bot.send_message
data:
message: Android TV smart plug load is to high. I switched out smart plug.
title: Home Assistant
target: xxxxxx
mode: single
If you read the first post, you can see that the current in the device was 0 before it burnt out. Because the load was switched off. And when it was on, it was powering a low power device.
This was a short circuit inside the smart plug, you won’t detect that with the plugs internal power meter (unless that is before the point where the short happens but it’s unlikely that it will be detected before the device breaks)
Moreover, this device, like many other similar ones, doesn’t have power measurement to start with.
Anyhow, feel free to try this out, it will not hurt I guess. But as a safety measure, trying to use wireless power reporting is too slow and too failure-prone to be useful generally. I would sooner use a physical fuse in series with the plug.
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Im not an electrician so maybe I didn’t understand.
Device was plugged in an outlet but there was no load on it because lava lamp or anything else wasn’t plugged in. And than devices caught fire.
You didn’t accidentally touch it some time before to see was it warm to the touch…
As the @indeeed said it will be nice to have power usage before this happened.
My whole household power monitoring is WiFi (esphome) based and does report in intervals of 50ms without failures. Would be interesting to in-cooperate that in a “power leakage” detection. But then it would be necessary to have all appliances (small and big) with individual power meters. Then all can be sum-up and calculated against the whole house power meter. When the later shows more than all individual power plugs together some sort of power leakage is happening which could be a device which produces heat and might fail.
But I expect this not to be possible with any random ZigBee or z-wave power meter plug for example - from my knowledge they often can’t be calibrated proper and worse - often report the power usage only every 10 seconds or less.
Some of my esphome smart plugs are configured to auto-off on overload. So for example a water pump with 1.5kW would turn off when the plug draws 1.6kW. It also has a under-power (dry run) protection and will turn off when the load is less than 1.2kW for more than 3 seconds. All possible without HA thanks to esphome!
50ms would be a reasonable interval I guess, for slow burning shorts at least. But imagine the load it would put on your Ha database… And also, the cheap smart plugs do not report power, I think you would improve safety more at equal cost by buying more expensive smart plugs with no reporting. But it’s an interesting thought experiment. Local measurement like you describe in your system sounds better already.
None of the monitoring is of any use for an internal device fault, unless the fault is falls into the circuit path at a point the draw would actually be detected. Not sure how likely or unlikely that would be.
In any event, the OP said his switch was already off, so an automated off command wouldn’t have been the solution.
Just for your information: The eBay seller profile lists a German, Italian and united kingdom tax number. So if you bought this probably from the “German store” (the eBay link was in German) which could entitle you at least for a refund if the device died within the 24 month warranty.