Dear community, I discovered a trouble with FSPC of my DYI System few days ago. I have Fronius Symo on the AC output of 3-phase configured Multis II. Even when the batteries are almost empty, if the grid fails, the microgrid rises the frequency to 53Hz every few second and does not allow Symo to connect (Error 105). I upgraded the firmware of the Multis few months ago but don’t know whether the trouble came before or after the upgrade. I haven’t tested the behavior for long time. After the installation it worked. The Symo was disconnected on grid failure but connected again and followed the FSPC. Do you have some idea? I spend hours with the configuration but everything seems OK and trials didn’t help. Thanks.
On firmware upgrade most settings are purged from MP2. Pls double check either ESS assistant with PV is installed or PV assistant. PV power is defined per phase. If you have 6kWp in a 3-phase system, put 2kWp.
Also check the frequencies.
Hi Björn, thanks for the quick reply. I know that all settings were lost on upgrade but I had a backup file. The PV power I have and always had per system, I can change it per phase, but does it really matter if the issue is given even at night with zero PV power? Of course, the Symo does not try to connect, but I observe the 53Hz bursts with oscilloscope.
Sorry in this case, I have no experience.
Only thing I could imagine would be a short term loss of BMS connection and internal battery monitor assumes 100% SoC due to different battery settings in VeConfigure.
The ESS Assistant says “Total power“, so why per phase? This settings are on L1 available. If I save the assistant and load to L2 and L3 there is only question about PV Inverter but no settings. I tried per phase but it didn’t help.
It seems the PV settings are stored only on L1. As I wrote above, there are no such settings on L2 and L3. And if I delete the old assistant, replace with the file from L1 and upload changes, they don’t transfer the 44 blocks and don’t restart.
The BMS is alive, I would see if there were some issues.
Hello, has someone the next idea? Is it possible that after FW upgrade I did something wrong when doing the 3 phase config new? Unfortunately I see no possibility to review these settings, only start from scratch. But on grid works everything fine.
Hello guys, today I got a good hint in the German speaking area. My test was not clean - due to my laziness I disconnected only one phase, typically L3 and thought it is enough because the grid & plant protection disconnects the grid completely anyway. But following the hint I tested disconnecting of all or other phases and found out that the strange behavior happens only if L1 (master Multi) is present. L2 and L3 have no influence. So I think if master sees the correct grid voltage and frequency the system prepares for synchronizing and disables the AC coupled sources by 53Hz. Not bug but feature? A bit suboptimal, we hat 1-phase grid failures with couple of hours duration several time.
So my question is now reduced to “is it possible to avoid this behavior if L1 remains?“ Thanks 