I have two problems on a 3-phase Victron Multiplus 5000/48/70-100 with battery pack (lead acid 24 x 2V / 1150 Ah each) operated as an island. Three SMA inverters and two Victron MPPT 150/60.
One is the gird supply: when the batteries are low (now visible due to less power production and more demand with a heat pump for heating the house)
The other is the freq.shifting for the inverters (SMA)
The grid supply assist doesn't work at all. The assistants are programmed (general flag and generator start-stop) but for some strange reason the grid doesn't start when batteries are low. I've upgraded the multiplus (all of them) to the latest firmware 487 and reprogrammed the system from blank. The same problem ...
The freq.shifting is even stranger, when the PV inverter Support assistant is programmed, the Multiplus continuously switches the inverters off and on (50 to 53 Hz). It starts working AFTER a heavy load (higher then the combined inverted power) ... after that it works normal
Both problems are a pain because or the batteries can be overcharged or the batteries can be completely discharged. Now I have to manually interfere all the time.
I've uploaded three VSC files (added the extension PDF otherwise I could not upload the files) for the multi's maybe someone can take a look and see if I'm doing something wrong.
SMA 1 = 3kw inverter = 3500 wP panels
SMA 2 = 3kw inverter = 3250 wP panels
SMA 3 = 3kw inverter = 3370 wP panels
Any help is appreciated !!!