This behavior started about 3 weeks ago.
By the time, I was running on the latest Beta VenusOS V3.80~12
The following configuration.
AC1 Is set to Generator (current limit is set to 16A)
AC2 is set to Grid (current limit is set to 20A = Grid circuit Breaker rating)
Both Solar chargers have the same amount of panels.
Both arrays are on the same roof side and are mounted with same angles and face the exact same direction
NO shading
NO clouds! The problem is that the MPPTs Operating Mode are constantly switching between 0, 1 and 2
0=Off
1=Voltage/current limited
2=MPPT active
I am logging via MQTT and displaying the data with Grafana and this is how a 5 Minute graph looks like:
MPP Charger Output Power and MppOperatingMode
What I have done so far:
Went numerous times through all settings, but can not find anything wrong
Disconnecting the MPPTs - by pulling the VE.Direct cables and reseting BMS-Control via Victron Connect -Bluetooth
Now the charger stayed ON but NO Grid Feed-in
additionally I did set the "GRID SETPOINT to - 4500W
THEN the grid feed-in starts working, but it is not using the Full Solar power
…and I had to control this by manually adjusting the grid set point
SO NO way this is going to stay like this.
I even did a clean OS install. Flashed the Venus OS from SD Card and downgraded to the official V3.67 - (still the same problem here)
then updated to V3.72 (this is the version currently running, but still the same problem
Any idea what could cause this behavior?
What else should I check?
I am out of ideas.
Have you installed a production version - 3.72?
Betas have issues and the main forum sections aren’t intended for betas.
If you have any modifications, remove them so there are no variables.
If you have dess, disable that.
There are just too many reasons issues like this happen, difficult to diagnose remotely.
That the mppts aren’t listed is an issue, I would be checking all the wiring carefully. For multiple mppts to disappear is highly unusual, typically there is a local issue being overlooked
It won’t work correctly if the mppts aren’t visible on the gx.
If you connect to them with the app do they show any history of error codes?
Disconnected they will work purely on bus voltage, exporting isn’t intended to work like that.
When they are connected at least you will have data in VRM that could show why they are shutting down.
What grid code are you using? Some limit exporting.
Yesterday, after sunset, I reconnected both MPPTs back to the CerboGX.
This morning, I was monitoring the system, from shortly before sunrise.
Both MPPTs did NOT switch to MppOperatingMode=2 even though there is bright sunlight
So I disconnected both MPPTs and disabled the BMS control.
Both chargers immediately started charging
@Jurgen_Pflug What changed three weeks ago? Unrelated, but why set an inverter limit of 8000W if it is only a 6400W unit? An ESS will not exceed it unlike an off-grid system that can be higher for short durations. Also, do you have AC coupled PV enabled, but I did not notice and AC inverter? Curious to note you have serious DC consumption is that correct and what DC consumer are you running? I did not notice DVCC settings in your post which should be enabled.
They are on, they are producing 180W give, or take, they just aren’t ramping up.
What are the BMS parameters at this time - CVL, CCL, DCL?
Have you compared the voltages (using a meter) at the battery terminals, the mppt terminals and the inverter?
What is the PV string voltage at this time (asked this earlier)?
What are the dvcc parameters?
When something works fine and then doesn’t, after no changes, it can be a poor connection somewhere that leads to voltage discrepancies, which will throw the system off.
it is 8000VA, not Watts. Its continuous wattage rating, after power factor, is 20% less and decreases with temperature.
It is a 6400W inverter as per the datasheet.
Also your temps seem high - battery at 34C - the system will be derating. The battery may even be limiting charging at that high reading.
Anything that could affect ESS could affect how the system works. It should typically be ignored, but I like to turn off anything that should not be enabled, including feed-in AC PV, if you don’t have any.
