Information on Battery-Backup Systems

Wiring and connection of automatic transfer switches for single-phase or three-phase battery-backup systems

1. Do not bridge the neutral conductors of connections X1 to X5 in the automatic transfer switch. If the neutral conductor connections are bridged, residual-current devices could trip accidentally.
2. Label the equipment and devices of the automatic transfer switch in accordance with the schematic diagrams. This will facilitate installation, commissioning and assistance in case servicing is required.

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.

1. 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).
2. 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.