hi, I measuring with the 3-phase IAMmeter the incoming energy to my house (main cables). I measure about 3.02 A in energy consumption on phase 3 (@230V - EU standard). Now when I activate my small solar system and put all energy on phase 3, I can see from my sensor on the solar system that it is producing about 900W (@230V). That would mean I produce about 3.9 A on phase 3.
My logic mind says I should measure 3.02A - 3.9A = -0.82 A. Well, the IAMmeter tells me the current is about 2.8 A. So no big change in the measured value. (the consumption inside my house did not change.)
So what is going on?
This is an article about the troubleshooting of the "wrong" power reading, we list many possibilities that cause a "wrong" power reading.
Or you can do this test firstly,
If all three-phase readings are nearly the same under this testing, it will prove the energy meter works correctly.
Then please check the wiring of your installation.
1 Connect Ua Ub and Uc together to the voltage of phase A,
2 clamp CTa Ctb and Ctc also to the wire of phase A.
Then compare the power ,voltage and current reading of the there phase reading, if they are nearly the same, it means the consistency is OK,
The power reading displayed in the IAMMETER cloud is the active power,not the apparent power reading
active power = V*I*Power factor
I think it is also the active power reading in your solar PV inverter monitoring system(provided by the solar inverter manufacturer)
To simplify the understanding, please just focus on the power reading first.
If the grid power of phase C is about 600W (measured by WEM3080T)
Then you turn on the solar PV inverter,it is a single-phase inverter, only connected in phase C
If your solar PV produces around 900W,
Then you will see a -300W in the phase C power reading from the IAMMETER energy meter. It means there is a feedin power (export energy to the grid) of 300w.
there is two premise about the result of -300W
1 power reading keep constant(both solar pv output and the grid consumption in phase C keep constant)
2 the energy meter should be in normal mode, not nem(net energy metering) mode. The normal mode is the default mode, so if you do not turn on the NEM manually, it should be in the normal mode.