AC Grid Impedance

What does 104 mean?

This status code indicates that the AC grid impedance is too high, preventing the Fronius Primo GEN24 208-240 inverter from operating correctly. This can be caused by long or undersized AC cables, or a generally weak utility grid connection.

• AC cable connecting the inverter to the grid is too long or has an insufficient cross-section, leading to increased impedance.
• The AC grid itself is too weak or has high internal impedance, making it unsuitable for inverter operation.

Click steps to track your progress.

1. 1

   Inspect the AC grid connection point for loose terminals or poor contact.

2. 2

   Verify the AC cabling to the inverter terminals (wire gauge and length) and ensure it meets installation guidelines to minimize impedance.

3. 3

   Observe the stability of the AC grid by monitoring voltage and current under load.

4. 4

   De-energize the inverter (switch off AC and DC disconnects), wait for 5 minutes, then re-energize to reset. If the message persists, the inverter may require service.