Unable to communicate with the power stage set

What does 401 mean?

This code indicates a loss of communication between the inverter's control system and its power stage set. This prevents proper operation, but the inverter will automatically attempt to re-establish communication and resume feeding energy into the grid.

• Interference or fault on the internal communication bus between control and power boards.
• Hardware malfunction of the power stage set or control system communication interfaces.
• Loose internal cabling connecting these components.

Click steps to track your progress.

1. 1

   If the status code is displayed continuously, notify a Fronius-trained service engineer for diagnosis.

2. 2

   Perform an AC reset by cycling the automatic circuit breaker to restart the inverter's internal communication.

3. 3

   Check for stable internal power supplies to both the control system and power stage set.