Metering total home power consumption

Hello All

I come here to ask for a tip :bulb:.
Currently I am completely changing electrical grid at my house (well not me, but a company is doing that for me). As they are doing it all from scratch i will also have a new box with circuit breakers etc , and i would like to do it in a way that i can meter real-time electric consumption of whole house (at once, and not every breaker one by one) and get this data into hassio.

Does anybody have experience how i could achieve this, what device exactly to buy exactly and you know it works?
Please understand that am not an electrician and dont really see deep into the topic and the guys who do the all the work dont really see deep into “smart devices” topic.
So ideally something I can put into the circuit breaker box right now and it will directly work without any long manual setup and later as the work is finish i can tweak it into hassio. One more thing which am not sure if it makes a big difference in the setup, but am using 21 kW electric boiler for heating up my house, so the consumption is rather high.
I have already found for example this device , i think it might be it?

Thank you for your tips :slight_smile:

That device won’t work :

measuring range with current clamps supplied: 5 - 14 500 W, 22 mA - 63 A

Quick calculation : 21kW x 240V = 87,5 A

Yes this I have seen as well…
I was wondering if there exists a solution which will meter the consumption completely, meaning it will be “free of the devices” that I use and will not need to consider such a high Amps of the boiler. Like it will not directly need to be included in the circuit with all the Amps, but i will only meter the consumption off all et the end. Maybe its stupid and electricity does not work like that and maybe a really need something strong in which all the power will flow so it can be metered.
I am having in mind the meter provided from electricty provider located on the street. This doesnt care about any device which I am using, its just showing the consumption…

21kW / 240V = 87.5A

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Dont know where you live, but here in the Netherlands (and some surrounding countries) we have smart meters with a port from which you can read this type of statistics. So talk to your electricty provider to see if they have smart meters you can interrogate with software.

Except the boiler is most likely three phase, so the current should be
I = 21kW / (230V * 3) = 30.4A

Also, fom the specs of the meter it seems like the phase voltage is 230V, not 240V.

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I have this kind of Meter. and the port, you mean this thing marked in blue right ? Cause meanwhile I have found this device Choose your OneMeter type | which is supposed to go into that port and works over wifi. Do you mean something similar ?

Thank you

Yep, on our meters it is a rj45 port which you can connect with a serial tos USB cable and then interrogate with python code.

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You’ll need to check with your distributor if you are allowed to use this port. E.g. ČEZ requires that you use a certified device to communicate with the meter: Komunikační rozhraní z elektroměru pro využití zákazníkem | ČEZ Distribuce (Czech).

ok again maybe stupid question - can not integrate “my own” meter like this into the power box? then i could do whatever i want with it. If yes, anybody got any recommendation which one to use?

Most Meter Reading Devices have so called P1 port, which you can use to get real time data. Unfortunately my meter at home doesn’t have one, but I found another way of getting the readings by using the Pulse LED marked as Imp/kWh.
You don’t need any special Engineering skills to build the device but you will need some basic soldering skills for it.
On the images below (hope they are visible) - you will see my setup.
Here is a link to the Author and his repository on GitHub.

Hope This Helps :slight_smile:


this will do the job, or some similar. 60 A per phase is more, than enough:

@reynsys Hm that thingy which counts the pulses look like nice home-hobby stuff to do, thanks for tip, maybe i will just use this solution.

@BebeMischa yeah that could do the job as well. Unfortunatelly am using Zigbee (ZHA) and not Z-wave. Not saying that its not possible to use both, but i have heart that it is not the best solution to use more. Not sure if its true…
And as I just learned in supported devices of ZHA page there is no such a device :confused: i guess i will need to stick to good old wifi, but havent found any other meaningful device than this.
But in this case i would rather avoid aliexpress and chinese device.
After some googling i have found this Shelly device . If i get it correctly, this can exactly do the job right? And i would need only 1 of this devices as it is 120A.

The Shelly is not made for 3 phase system.

This one is:

I really doubt that a residential customer would get 3 phase wired into the house for a boiler.

even if that really is the case your calculations are incorrect.

P = √3 * pf * I * V

usually the pf = 0.8

21kw = √3 * 0.8 * I * 240v


I = 21kw/(√3 * 0.8 * 240v) = 63.14A per line

This one is :

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Again, I’m not even sure why we are discussing 3 phase.

Did I miss something where the OP said he actually had 3 phase power delivered to his house?

it may be different in other parts of the world but in the US that is almost unheard of unless you also have a commercial shop on the property.

It is very common in Czech republic and Slovakia, outside the big cities. On the villages almost everyone has 3 phase power. That’s made years ago by the electrification, so that they can maintain evenly spread distribution with less chance for outage.
My summer house in CZ also has 3 phase connection. And a 3 phase water boiler. Like all my neighbors.

Judging from the writings on the meter (Západoslovenská distribučná), OP is from Slovakia. I’m from the Czech Republic and 3 phase is the standard here.

The phase voltage in Slovakia is 230V, not 240V.
I would expect the boiler to be a mostly resistive load, so I just went with a power factor of 1. I could be wrong though.
P = sqrt(3) * pf * I * V is for line voltage and line current. 230V is the phase voltage. Line voltage is 400V.


never mind me then…

carry on… :slightly_smiling_face:

and people say we are dangerous over in the US for having 240v single phase in our houses. :laughing: