Backup mode with an automatic backup box

A backup box changes over automatically if there is a grid failure and disconnects the public grid from the house grid. Generally, the user does not need to do anything to switch from grid mode to backup mode and vice versa. The changeover is fully automatic in both directions.

The steps described here may differ depending on the backup box fitted. Further information on your backup box can be found in the manufacturer's instructions.

The backup function must be activated during initial commissioning or by changing the operating mode in the inverter. Depending on the hardware installed, you can choose between a manual and an automatic backup box. This setting can only be configured by an installer.

Procedure using an automatic backup box if there is a grid failure

  1. As soon as the public grid fails, you will receive an event message on the inverter.
  2. The red LED on the inverter lights up for a fault.
  3. The following event messages are displayed on the status line:
    - 6021 (The public grid has failed. The inverter is ready to start backup mode.)
    - 6006 (Sensor information cannot be retrieved)
  4. After a wait time of approx. 30 seconds, the inverter sends a switching signal to the backup box to disconnect the house grid from the public grid.
  5. The inverter then establishes a backup power network and switches to backup mode.
  6. The red and green LEDs light up on the inverter.
  7. The following event message is displayed on the status line:
    Backup mode.
  1. Backup mode active.

What are the required steps if the inverter shuts down when there is an overload?

If there is an overload, the inverter tries to establish a backup power network three times before it shuts down.

The inverter display then shows a message that the load should be reduced.

  1. Shut down consumers in the house grid to reduce the load.
  2. Acknowledge the message on the display.
  3. The inverter now tries to establish a backup power network again.

If it is still not possible to establish a backup power network, reduce the consumers further.

Do not switch the inverter off in backup mode if PV energy is no longer available. The inverter cannot establish a connection to the battery if it has been switched off because there are only a few battery types (e.g. BYD) that supply the inverter's communication board with energy.

Procedure using an automatic backup box when the grid returns

The KOSTAL Smart Energy Meter measures the grid parameters for the public grid at the grid connection point. As soon as the grid is available again, the KOSTAL Smart Energy Meter forwards this information to the inverter.

  1. As soon as the public grid is available again, you will receive an event message on the inverter display.
  2. The red LED on the inverter goes off.
  3. After a wait time of approx. 60 seconds, the inverter sends a switching signal to the backup box to reconnect the public grid.
  4. The backup box changes over to grid mode.
  5. All consumers are immediately connected to the public grid again and can be used.
  6. The inverter starts up again after approx. 90 seconds, depending on the grid guidelines, and can feed in to the public grid again.
  7. The green LED lights up on the inverter.
  1. Grid mode is active again.