Backup power operation not possible

What does 901 mean?

The Fronius Primo GEN24 208-240 inverter is unable to switch to or maintain backup power operation (PV Point or Essential Backup). This means the system cannot provide emergency power to critical loads during a grid outage.

• Backup power operation not possible.
• Battery not connected.
• Battery not charged.
• Grid still present (backup power not required).
• Incorrect wiring of backup power connection.
• Faulty transfer switch (external or internal).

Click steps to track your progress.

1. 1

   Verify that a compatible battery system is correctly connected to the Fronius Primo GEN24 208-240 inverter and is sufficiently charged for backup operation.

2. 2

   Check the status of the public grid; backup power will only activate during a grid outage.

3. 3

   Inspect the wiring and connections for the backup power circuit (e.g., PV Point, Essential Backup box) to ensure they are correctly installed as per the manual.

4. 4

   If an external transfer switch or contactor is used, verify its operational status and control signals.

5. 5

   Ensure all necessary backup power features are enabled in the inverter's settings (e.g., "PV Point active" or "Essential Backup mode").