Medir el consumo energético ayuda a conocer los gastos operacionales, personalmente utilizo MODBUS con medidores de energía, por medio de https://libmodbus.org/ realizo lectura y cálculos.
No soy operador de nodo pero probablemente esto ayude a alguno.
For US users, Emporia Energy makes quite a few interesting products that help measure power consumption in a somewhat centralized way, on a per-circuit basis.
There are a few outlet type products, like Eve Energy Outlet, TP-Link smart plug (this is not an endorsement, just examples, they are all varying degree of crap), some even integrate to HomeKit, that help measure power consumption at the outlet level.
However, most server motherboards and power supplies already include circuitry for measuring power consumption anyway, so no extra hardware is required
Measure power on motherboard won’t be of help in some situation, for example: if you have a modular system - hdd 3.5 via hdd enclosure, extra usb hub with it own power supply, etc… Then the only option left is to measure at power socket.
You must take into account your PSU and UPS eficiency. So you need to mesure at the wall.
I used also smart plugs, I don’t know how accurate they were, some more expensive than others, but:
This is measured by the PSU, and reported to the BMC
UPS is pass-through when power is present.
HomeKit solves it. Obviously, don’t give those plugs access to the internet!
You don’t need “most accurate” though – you just need a ballpark.
That’s show Emporia Energy devices are measuring power - except they use current probe, not replacement switch, which is a huge liability problem. I don’t want my AFCI circuit breakers to have any extra smarts that does not absolutely need to be there.
Well, if I read this correctly, then all of this is unnecessary. I use a Shelly for all my energy metering. I use the following:
For the system itself: Shelly Plus Plug S
And for the entire house: Shelly 3EM
I don’t know how it is in the US, but here in Germany, it’s pretty cheap to get. Plus, you can see the power consumption of each day without writing it down or needing to go there.
I use a couple of similar devices. Mine even have pulse outputs (one pulse per Wh), I can connect a raspberry or whatever to count the pulses so I do not need to write down what it indicates.
That energy meter is not a circuit breaker, it just looks like one, or rather, it is designed to be mounted on a DIN rail alongside the circuit breakers and other stuff on there.
However, what the OP made is also OK IMO. I have made a similar thing myself, I used a C14 connector and a C13 connector instead of regular plug and socket.
It may also have ethernet connection, but that’s the same. I had the same problem with the inverter for my solar panels. Instead of being able to get the data directly, it would put it on some Chinese server where I probably could access it using an API. Thankfully it was possible to remove the module and just use modbus to get the data.
It’s more likely some instance on Amazon AWS, but even if it is some Chinese server – what’s the problem with that? It either works reliably or it does not. Who owns the servers is quite irrelevant.
Or are you worried that your power usage data will be used in some unsavory way? I personally would not care. They can use whatever they want with that data.
Until the manufacturer decides to limit the API accessibility (or ask money for it) or stops supporting my device completely (or starts asking for money).
I mean running the server is not free, why should I expect the manufacturer to give me access for free forever?
You may, actually… But need to check every month or so.
It’s better to have a backup plan of course.
I don’t get it. How would an isolation transformer help the lack of ground?
By isolating everything from the mains. Now shorting either ends to the ground produces virtually no current. No current – no problem.
Most (in statistical words: all) countries earth the neutral on the stepdown transformers (that step down voltage for your neighborhood). That means that if there is any fault with live (ie a mouse chewed through the wire isolation) and your fridge’s casing is now at live voltage, you’ll get electrocuted (assuming GFCI/RCD isn’t there), because your body is now completing the “circuit” back to the transformer’s neutral through earth (or at least part of it, ie in parallel to the existing neutral).
Isolation transformers don’t have their neutral earthed. That means that there is only one path back to the transformer: the neutral. Even if you touch live, there isn’t any physical path back to the transformer, so no current flows through you. The only way for you to get electrocuted is when holding live in one hand and you touch neutral. Measuring voltage across live and earth will show zero.
Look it up, they are used in all electrical engineering labs around the world for exactly this reason.
Yep. I get it now. With a transformer you get a high impedance between live and earth. Never seen such a thing, even though I work in a somewhat electrical engineering lab… 
Today GFCI (RCD) breakers not only exist but are more cost effective than a massive transformer.
Where I live it’s mandatory to have AFCI breakers and GFCI outlets near water (kitchen/bathroom/etc). These two approaches prevent house fires (by detecting sparks in walls when the insulation deteriorates) and save people by breaking when small imbalance of current is detected.
Except when RCD fails to operate within the stated response time. ANY protection device whether it is an RCD/GFCI, MCB or RCBO is dependent on the fault current. The lower the fault current, the slower it will respond.
FYI: death can occur at 45mA by heart palpitation.
This is not avoidable unfortunately. It’s also depends on the skin resistance, my is 900 MOm, so I survived 20k volts shortcuts twice.
No, never is you skin resistance 900 MOhm. That’s impossible to have. A 20k Volt line will instantly kill you
Even we in Germany have “only” 230V power (ignoring the 400v power between phases). And If you touch it you will definitely trip an rcd with 30mA rating
ok. I would assume that I’m unique…
Not to proud, but we need to pull out the electronic components from the power cell before we would try to fix it.
And I still alive.
I wouldn’t say that touching 20k charged condenser have no influence on me… I just found myself on 4 meters out of the box somehow (I just do not remember how). So… Do not touch the charged wires…
