Today I experienced some strange behavior. It seems that on phase 3 a constantly high value is being calculated, even though nothing is connected to the AC load; everything is connected to AC Input 1.
Because of this, 7 kWh was fed back into the grid while the battery is not fully charged.
I have never seen this behavior before. On L3, at certain moments, it showed more than 1100 W while nothing was connected. Could there be something wrong with the calculation of phase 3?
For example, Home Wizard shows that I am feeding back 1000 W, while the GX only shows 300 W being fed back.
System:
3 Fase - MultiPlus-II 48/5000/70-50
VM-3P75CT HQ2419A7WHP
I take already the following actions:
Update GX to lastest version
VM-3P75CT HQ2419A7WHP power off and on
Disconnect Home Wizard , to check if this was incorrect.
I did some testing, and the induction cooktop is connected to phase 3. If nothing is connected to AC Input 1 and nothing is connected to AC Loads, the calculation doesn’t seem to work correctly. As soon as I turn on the induction cooktop, the AC Load drops to 0.
The emphase solar panels are also connected in L3, so during the day there is only feed back to the grid.
I did a check to compare the Fase 3 value of the home wizard and victron
The VM-3P75CT HQ2419A7WHP is not messuring the correct value any more of fase 3
All groups are on AC out 1, so I can also let the inverters determine the phase.
I have now set the grid measurement to inverter/charger. I have disabled the VM-3P75CT.
Now phase 3 is determined correctly, and hopefully the system will work normally again.
I am going to request a new VM-3P75CT from my supplier because L3 is no longer being measured correctly. This meters is not a year old.
It might be helpful if someone could advise whether it would be better not to use a VM-3P75CT at all in my case. Only if I connect something to the AC load would this meter need to work again.
The system has been working well since February, so I don’t think there is anything wrong with the CT clamps. I will check this on Friday, but I don’t think that can be the problem.
I checked the clamps. They were all clicked into place, but I still had the feeling that they weren’t closed properly. To be on the safe side, I put cable ties around the clamps to make sure they were closed properly.
The measurement deviation of phase 3 was still present. It seemed to be slightly smaller, but it was still not being measured correctly.
After installing the cable ties, the difference was much smaller. That’s why I did another measurement, and now the difference seems minimal. I’ve now put the ESS back on the VM meter, and in Home Wizard, the energy is fluctuating around 0 again. Perhaps the clamps weren’t tight enough and firmware version 1.10 helped. Now I’ll wait a few days to see if it continues to work properly. In any case, it’s nice that I can always fall back on the meter of the inverter/charger.
Everything has been working fine for a few days now. The ESS is keeping everything at zero to the mains. The cable tie and the firmware seem to have solved the problem. I will keep an eye on it.
