EV Charger plus EM540 on Ac-In wrong power consumption calculation

[MoJo]

Hello,

At first my system setup: 3x multiplus II, Battery, Cerbo GX (Venus OS 3.53), EVCharger on ACIn ( Firmware EVCS_Main_FW_OTA_V02.01_C025.evcsup), EM540 on ACIn before EVCharger in order to exactly measure the EV consumption, No more ACin loads, GridMeter Kostal KSEM, …

My Problem: After adding EVCS without EM540 connection everything worked and was displayed correctly (EVCS on left ACIn side, correct Power ratings - but EVCS readings were a bit inaccurate). As soon as I activated additionally the EM540 readout via RS485 (on the AC supply to the EVCS) things got a little bit strange.

Ev Charger in Venus OS jumped to the right side. EV consumption is doubled as EM540 and EVCharger are summed up. Details:

VRM Error on left side: EVCharger states 14+ kW. Overall power balance seems good, EM540 current is taken into account:

EVCS Homescreen seems to be valid - mostly:

Venus OS gui V2 has an interesting interpretation about what’s going on → AC load 8 kW and from there 15 kW EVCS Load:

My detailed settings:

Question: Did I configure something wrong here? Can this be fixed through Venus OS settings?
Any help is highly appreciated!

Bg and tia,

MoJo

[nuxland]

I’m also figuring out how to correct that Victron own EVCS power so that it would show correct numbers. There is calibration table for different Ampers. And I have there 0.96 for 16A but as seen in this node-red graph (light line is shelly meter and dark is EVCS reported) that EVCS is calculating it’s power so fluctuatingly.

It would be great if I could disable victron self EVCS power calculation and via modbus could inject my calculated power to it.
Then in VRM all the kWh and power values are actually correct.

Maybe @Lpopescu can answer how EVCS is calculating it’s power value.

[Lpopescu (Lucian Popescu)]

Hi, no unfortunately not