Helle there,
i use a helper as a counter.
It counts power over a period of one day.
In this case it counts the Watt/kWh of a Shelly 3EM over one day.
The results differ around 30-40% from reality.
This is what i experienced with every counter i used.
What am i doing wrong.
But you show a kW helper while you talk about kWh and a utility meter cannot do that conversion.You compare to a kWh sensor from the Shelly.
You can apply the utility meter directly to the kWh sensor from the Shelly. If you are converting kW to kWh you’re probably doing that wrong, but you don’t need to.
But the whole point is kW is something entirely different from kWh. It is like the difference between speed and distance traveled. If you want to convert kW to kWh you need a Riemann sum integral, but there’s no need, because you already have the kWh. Putting kW in a utility meter yields useless results. Just put the kWh sensor in the utility meter and you are done.