In the manual it is written “In the event of a grid failure, or shore or generator power being disconnected, the inverter within the MultiPlus Compact is automatically activated and takes over supply to the connected loads.”
Is there a way to have the inverter activated when the power on ACIN is present; ie using solar energy or battery power until the battery reaches a minimum level ( use the grid power only when the inverter cannot supply: no more battery or power on ACOUT too high) ?
ESS offers this functionality, but you have to make sure it is adequately certified (approved) by the grid operator for this, where you plan on using it as it synchronises with and feeds power into the grid supply. It is also intended for fixed installations. Do a search on the Victron website for ESS.
For offgrid/boat use solar and wind priority is an option.
It is not as configurable as ess.