I have 2 MultiPlus 12/3000/120 50/230. They are on different vehicles. One uses 11x50Ah gel batteries, second uses 4x110Ah flooded batteries. First one works fine 2 years, second more than year. Problems starts a mont ago. One (with gel batteries) not working on generator power. It tries several times switch to "mains", but stays on "inverting" mode. I tried 4kVA generator and 1kVA inverter-generator (charger only). I also using Digital multi control 200 and input current is limited accordingly. Works almost fine on grid power. If I connect grid power, or my 30kVA generator it switch to "mains" after 2...10 mins. I used MK3 to monitor system. I resetted several times all settings. Also upgraded firmware what I get from local seller.
Looks like some issues with synchronizing. Generator empty run voltage is 240...250V and frequency is 51...53Hz (different units) Multiplus can see input frequency and voltage, tries to keep frequency similar to input, but not switching over. Wide input voltage and frequency range are allowed. Grid frequency is 49,9...50,1 and voltage 225...235. Large generator running at 50,5...50,7Hz and 235V (no load).
second set runs fine, works fine on random generator and on grid power. Settings are same.
