I have an issue with my 12/300/120 Multiplus. When on shore power, and set to Charger Only mode, (majority of time), there have been three occasions now when the unit has tripped to "overload" for no apparent reason.
AC loads are minimal, probably 2-300W, DC loads also low, 3 - 11A depending status of fridge / freezer and any lights on.
I had thought the first time that "UPS Mode" may have been a factor but this has been disabled.
Batteries are 4 x Rolls 400 series flooded lead acid, 130Ah ea. Other Victron in the system currently just the BMV712, with 100/30MPPT and Colour GX controller to be fitted soon.
I can give more detail and photos when I get back to the boat in a week or two, including current firmware, which I know is not the latest.
The unit was not installed by me but already installed in the boat.