ESPEasy to guard meter-box

[manjh]

After a two-week holiday, I came back home to find the "earth leakage circuit breaker" (is that an English word?) to have tripped. A good part of my house was without power, including the freezer. Opening the lid was not pleasant, all food was thawed and rotting. I will spare you more details.

So, after cleaning the thing, I began to think how I can prevent this happening again.
Can't prevent the circuit breaker to trip, but at least I want to know about it.

What comes to mind is link an ESP unit to each group, sending out a heartbeat every few minutes. This way the Domoticz server could keep track, and raise an alarm (e-mail) if a unit dies because the power is cut.
But this would take about ten separate units, and then there is the question of how to connect them all. Best place would be the meter box, but 10 units... I could also use an outlet in different rooms, covering all groups.
Alternative is one ESP unit, able to detect power in ten different lines. But how?

So I though I'd throw this out on this forum. Any bright ideas?

[Hairyloon]

There is a circuit here for using an arduino to measure AC voltage, you could follow that principle perhaps?
I'm not sure that you would need the transformer: you could just rectify the AC and use a voltage divider, but that instinctively feels dangerous...

I expect somebody who knows what they are talking about will be along shortly to shout at me for suggesting it.

[ThomasB]

What comes to mind is link an ESP unit to each group, sending out a heartbeat every few minutes. This way the Domoticz server could keep track, and raise an alarm (e-mail) if a unit dies because the power is cut.

As you have recognized, there is no need to monitor voltages because a missing heartbeat triggers the Domoticz actions. Just be sure that the Domoticz server and all required WiFi hubs/routers are on UPS backups.

But this would take about ten separate units, and then there is the question of how to connect them all.

Installing a ESPEasy device on each dedicated circuit (plugged into a convenient outlet location) is the least intrusive way to do it. Each device sends a heartbeat for the household circuit it is guarding.

Reflashed Sonoff Basics would be low cost hosts for this application (https://www.itead.cc/sonoff-wifi-wireless-switch-1.html). Where aesthetics are important I suggest flashing nice looking plug-in AC outlets. Something like the Sonoff S20 (https://www.itead.cc/smart-socket.html).

- Thomas

[manjh]

Makes sense. I was already thinking of an advanced device, connecting to each of the groups, but a more pragmatic approach makes more sense.
I already have about 15 devices, I think I will take inventory to see which groups they are attached to. With a bit of luck I will only have a few left open, and I will simply use an ESP device extra for those.
Next step is to create a Domoticz script to keep track and report.

As for UPS, I am thinking of a powerbank for the R-Pi. Not sure how much that would hold, but it's worth trying.

[Wiki]

An useful UPS for the Raspi you find here: https://m.reichelt.de/raspberry-pi-usv- ... 69883.html. I am uwing it for a clean shutdown of the Raspi in my car.

[TD-er]

The "aardlekschakelaar" you're talking about is probably not 1-to-1 mapped to a circuit group in your house.

According to the NEN1010 regulations, you may have up-to 4 groups on one earth leak breaker circuit.
So that may give some 'discount' in the number of units needed.

Another thing you may want to reconsider.
Is it possible to set the refrigerator to some other group which is less likely to be 'hit' when some device trips that breaker?

In my experience, the group with TL-light and the group with solar panel converter is more likely to hit the 30 mA limit for that breaker.
So you don't want those to be on the same set of groups (on the same "aardlekschakelaar") as the fridge.

Oh and one last remark.
Those earth leak breakers may also be triggered during a thunderstorm.

[manjh]

The "aardlekschakelaar" you're talking about is probably not 1-to-1 mapped to a circuit group in your house.

According to the NEN1010 regulations, you may have up-to 4 groups on one earth leak breaker circuit.
So that may give some 'discount' in the number of units needed.

Another thing you may want to reconsider.
Is it possible to set the refrigerator to some other group which is less likely to be 'hit' when some device trips that breaker?

In my experience, the group with TL-light and the group with solar panel converter is more likely to hit the 30 mA limit for that breaker.
So you don't want those to be on the same set of groups (on the same "aardlekschakelaar") as the fridge.

Oh and one last remark.
Those earth leak breakers may also be triggered during a thunderstorm.

Yes, correct. In my house I have 4 groups connected to the breaker. Changing the freezer to a non-protected group would be a solution, but not available in the area where the freezer is. I would have to look into a separate cable.
But when thinking about a solution for the earth breaker, I thought I might as well try to keep track of all groups. All of them are protected by a regular 16Amp circuit breaker.

As for the cause: in my Domoticz log files I found the last entry on June 6th, 01.30AM. This makes means that a thunder storm could have been the cause to trip the breaker.

[Micha_he]

Maybe better, one relay for each power supply circle. Vcc looped over all relay to GPIO from the ESP. If the signal goes to zero, check all earth leakage circuit braker.

circuit.png (9.14 KiB) Viewed 26053 times

[manjh]

Maybe better, one relay for each power supply circle. Vcc looped over all relay to GPIO from the ESP. If the signal goes to zero, check all earth leakage circuit braker.
circuit.png

Why two relays? Could just feed the switched output of the first relay to the ESP?
The downside is that I would have to somehow install relays on each group in the meterbox, and I'm not sure how legal that is. It would have to be in a closed housing, since there is live 230V involved. The output of the relay is not a problem.
Is there some kind of professional solution? Designed in the switchbox itself?

[TD-er]

How do you feed the ESP?
So I guess you will need to look for "keep alive" messages to see if it is still online.

Relays on 230V is not really an issue, but I guess it is quite big and may still use some power to activate the relays in normal operations.

[mrwee]

https://www.aliexpress.com/item/3282824 ... 4c4djFFY1n is much better than using a relay. I'm using it to detect 230V presence and it works fine.

[TD-er]

https://www.aliexpress.com/item/3282824 ... 4c4djFFY1n is much better than using a relay. I'm using it to detect 230V presence and it works fine.

Such a big resistor does not look like a very energy efficient solution.
Also you must make sure to wrap it all in some kind of enclosure (and consider the heat of the resistor), since the biggest part of the PCB will be connected to mains.

[mrwee]

I do think it's better than an AC relay at least. Maybe a solidstate variant is a better choice. But yes, always take your precautions when working with mains, it can kill

[manjh]

Looks like a good solution, but only when monitoring multiple groups in one ESP. The alternative is very simple: conect the power supply of the ESP unit to the group to be monitored. The "uptime" signal is sufficient for a smart Domoticz script to indicate the power is "on".

[manjh]

https://www.aliexpress.com/item/3282824 ... 4c4djFFY1n is much better than using a relay. I'm using it to detect 230V presence and it works fine.

Not bad for this price. Except that I would need 8 or 10 to build a central solution to the problem, plus a solid case to put all sensors in.
Strange that there is a shipment charge for each sensor. Ordering one is not too bad, but ordering 10 makes a large cost for shipping.

[manjh]

Found one that checks 8 groups in one board. Looks OK, or am I missing something?

https://www.aliexpress.com/item/AC-220V ... 070fe394f7

[ThomasB]

Found one that checks 8 groups in one board. Looks OK, or am I missing something?

I'm using the single channel version in a washing machine. Although designed for 220VAC, it is reliably sensing North American 120VAC.

But I am VERY hesitant to recommend these Chinese made boards. They seem to have very little regard for electrical safety. I seriously doubt the boards would pass electrical agency regulations in a western country.

I think your heartbeat concept that uses a ESPEasy flashed device on each circuit (plugged into a convenient outlet) is the safest solution. Especially if the host hardware has authentic CE or UL markings on it. For example, a Sonoff S20 smart socket. https://sonoff.itead.cc/en/products/res ... s20-socket

- Thomas

[manjh]

Found one that checks 8 groups in one board. Looks OK, or am I missing something?

I'm using the single channel version in a washing machine. Although designed for 220VAC, it is reliably sensing North American 120VAC.

But I am VERY hesitant to recommend these Chinese made boards. They seem to have very little regard for electrical safety. I seriously doubt the boards would pass electrical agency regulations in a western country.

I think your heartbeat concept that uses a ESPEasy flashed device on each circuit (plugged into a convenient outlet) is the safest solution. Especially if the host hardware has authentic CE or UL markings on it. For example, a Sonoff S20 smart socket. https://sonoff.itead.cc/en/products/res ... s20-socket

- Thomas

Thanks. My heartbeat approach is the most pragmatic, although setting up a central control unit in the meter box seems more thorough.
As for electrical safety: after looking at this particular board, I think I've seen worse. Comes close to the early Sonoff units.

[ThomasB]

I agree that using that circuit sensor inside the load center (mains electrical panel) is a low cost elegant solution. But it's not my cup of tea; Along with general safety concerns, I don't want to give my home insurance provider a reason to deny a claim due to unaccepted devices inside the panel.

But everyone has a different opinion to hacking things like this. So it won't continue to nag and instead just say to do what you think is best for your project.

- Thomas

[manjh]

I agree that using that circuit sensor inside the load center (mains electrical panel) is a low cost elegant solution. But it's not my cup of tea; Along with general safety concerns, I don't want to give my home insurance provider a reason to deny a claim due to unaccepted devices inside the panel.

But everyone has a different opinion to hacking things like this. So it won't continue to nag and instead just say to do what you think is best for your project.

- Thomas

I fully agree. Insurance came to my mind as well, even when a fire is caused by some otter reason, the fact that I tinkered around inside the panel with Chinese gadgets could be frowned upon... strangely enough, plugging them in to a normal outlet seems a bit more safe...