SMA Backup 3P Kit (BU-SBSE-3P-50) is an automatic transfer switching device that enables single-phase battery-backup operation with phase coupling in the SMA Home Energy Solution together with the Sunny Boy Smart Energy. It is suitable for households with a three-phase grid connection.
The SMA Backup 3P Kit can be operated in parallel grid operation and in battery-backup operation. In the event of a power outage, the SMA Backup 3P Kit disconnects the connection to the utility grid and automatically switches to battery-backup operation so that the hybrid inverter can supply the entire household with power from the battery and the PV system. Only L1 is monitored at all times. If the utility grid fails on L2 or L3, the automatic transfer switching device does not switch to battery-backup operation. During battery-backup operation, the hybrid inverter provides the same voltage to all 3 line conductors. | 
