Switching Times for Loads

The SMA Home Energy Solution with battery-backup function does not fulfill the requirements of an uninterruptible power supply as per IEC 62040. In the event of grid failure, an automatic transfer switching device disconnects the battery-backup grid from the utility grid. After disconnection, the loads and the PV system are not supplied for approximately five to seven seconds, until the battery-backup system can provide active power and reactive power again.

If any single load (e.g. a computer) requires an uninterruptible power supply in compliance with the standard or a switching time shorter than five to seven seconds, this load will need a separate uninterruptible power supply in accordance with IEC 62040.

Longer switching periods for phase coupling

Loads integrated in the battery-backup grid via phase coupling have a higher switching time, as the SMA Home Energy Solution with battery-backup function connects phase coupling with a time delay:

• Maximum switching time for Sunny Island: 15 seconds

• Maximum switching time for Sunny Boy Smart Energy: 10 seconds