Battery-backup function
The inverter is equipped with a battery-backup function. The battery-backup function is disabled by default and must be enabled via the user interface. The configuration is set on the user interface of the inverter.
The battery-backup function ensures that the inverter forms a three-phase battery-backup grid that uses energy from the battery and the PV system that is directly connected to the inverter to supply the circuits of the household grid in the event of a utility grid failure. If automatic battery-backup operation is activated, the selected backup loads connected to the AC-BACKUP terminal are connected and supplied to the AC-GRID terminal in parallel grid operation mode via an integrated bypass contactor. In the event of a grid failure, the contactor opens. The inverter provides a stand-alone grid and the backup loads continue to be supplied by the energy stored in the battery and the PV modules connected directly to the inverter. The charging of the battery is ensured by the existing PV system during battery-backup operation. As soon as the utility grid is available again, the battery-backup operation is disabled automatically and the loads are supplied with energy from the household grid. When the utility grid is down and the battery fully discharged, there is, in the beginning, not enough power available to create a stable battery-backup grid. In this case, the battery must be charged by the PV system. The inverter is able to create a stable battery-backup grid only when enough power is available in the battery. Battery-backup operation starts automatically as soon as enough energy is available from the PV system. By setting parameters, it is possible to define up to which state of charge the battery is charged and discharged. For example, it is possible to set the amount of energy that should remain in the battery for battery-backup operation.
Communication between the inverter and the SMA apps takes place via a direct Wi-Fi connection in battery-backup operation.
Do not connect any loads that require an uninterrupted energy supply
The secure power supply operation and the battery-backup operation may not be used for loads that require a uninterrupted energy supply. The energy that is available during the secure power supply operation or battery-backup operation depends on the battery capacity available and the state of charge of the battery (SOC).
- Do not connect loads if they are dependent on an uninterrupted energy supply for reliable operation.