SMA SUNNY ISLAND 4.4M Operating Manual page 17

SMA Solar Technology AG
Connection of automatic transfer switches for single-phase battery-backup systems
In single-phase battery-backup systems, only the line conductor of the Sunny Island that is connected to the circuit
breaker F1 of the automatic transfer switch is monitored for grid failure. If terminal AC2 Gen/Grid L is connected
to another line conductor, the battery-backup system is not able to synchronize with the utility grid following a grid
failure.
• With single-phase battery-backup systems, connect circuit breaker F1 and terminal AC2 Gen/Grid L of the
Sunny Island to the same line conductor, e.g. to L1 (for a single-phase battery-backup system with an all-pole
disconnection function).
• Connect the PV inverter and the Sunny Island to the same line conductor if possible. This way, in the event of
grid failure, the PV inverters are supplied with voltage directly and then can feed in even if phase coupling is
deactivated.
Operating Manual SI44M-80H-12-BE-en-10
2 Safety
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