Internal fault (e.g. general hardware)

What does 721 mean?

The Fronius Primo GEN24 208-240 inverter has detected a general internal hardware fault that is not covered by more specific error codes. This indicates a broad malfunction within the inverter's electronic components, preventing normal operation.

• Internal fault (e.g. general hardware).

Click steps to track your progress.

1. 1

   Perform a complete power cycle of the Fronius Primo GEN24 208-240 inverter: Open the AC circuit breaker, then the DC disconnector, wait for at least 5 minutes, and then reclose them in reverse order (DC first, then AC).

2. 2

   Check the inverter's event log for any other codes that might have appeared previously and could provide context for this general hardware fault.

3. 3

   Ensure the inverter's environment is within operating specifications (temperature, humidity) and that there are no signs of physical impact or water damage.

4. 4

   Verify that the firmware is the latest version, as general hardware stability can sometimes be improved by software updates.

5. 5

   If the fault persists, this indicates a severe internal hardware failure; contact Fronius service immediately for advanced diagnostics and potential main board replacement.