Hello, I have a system that consists of 2 MPII and one fronius primo 3.8kW.
I can get them to work correctly, first, i am unable to see the voltage or the current of the Primo, another issue that i have is that whenever there is low ac load and the primo works at full power, the MPII increases the frequency, making it disconnect from the system.
While your system is grid connected, the Multiplus can’t raise it’s frequency to drop off the inverter. It has to stay in sync with the grid frequency. That means, the primo is disconnecting on its own.
Eventually the voltage / frequency is rising over the primos limits, because your grid is overloaded during the hours of full power from you and other neighbours?
You can check VRM Advanced graphs for the ACIN frequency and voltage during these drops to see if that may be the case.
Makes sense.
i don’t see any disturbance in the voltage
When looking at this frequency values, you only get an indication, they can change quickly, but VRM will only log according to your logging interval (smallest is 1 min) and then even do some averaging, depending on the visual width of the graph.
So that indicates that there was most likely a raise in frequency that went well above drop-off frequency.
Also add the Input frequency, too see if that spike “came from grid” itself.
On posted graphs I see voltages up to 129V which seem high to me, for a 120V grid.
As dognose mentioned, looks like Primo is gradually reducing power and eventually stop production, to compensate high grid voltage.
During this periods, please check Primo’s LCD, if this is the case, it should show “State 567” during powe reduction or even an error code during complete stop.
Might be.. what i find weird is that it only disconnects when my loads are lower than 1kW and the primo is at full power it doesn’t disconnect under other circumstances
I think the VRM frequency of 60.3Hz is some bug. I have the same frequency difference.
