AI L2 Under Voltage

What does F35 mean?

This fault indicates an L2 under-voltage condition (108 V) detected by the anti-islanding protection, triggering a slow disconnect. This mechanism ensures the inverter disconnects from an unstable grid, protecting both the inverter and grid from potential damage due to insufficient voltage.

• Grid L2-Neutral voltage dropping below 108 V for a sustained period, indicating persistent grid brownout or heavy load drawing power from phase L2.
• Undersized utility grid connection or long feeder cables causing significant voltage drop on phase L2 under normal operating loads.
• Inverter's L2 voltage sensing circuit experiencing a degradation in accuracy or intermittent measurement loss over time.
• Anti-islanding parameter P_AI_L2_Volt_Min_Slow set too high, triggering disconnects on minor, acceptable voltage dips.

Click steps to track your progress.

1. 1

   Using a true RMS multimeter, continuously monitor the L2-Neutral voltage at the inverter's AC input terminal L2 over several hours to detect persistent low voltage.

2. 2

   Compare the sustained L2-Neutral voltage readings against the specified 108 V trip threshold and the inverter's P_AI_L2_Volt_Min_Slow parameter.

3. 3

   Verify the tightness and condition of the L2 phase and neutral conductor connections at the inverter's input terminals (e.g., Terminal L2, Terminal N).

4. 4

   Investigate the local grid connection for other large loads drawing power from phase L2 that might cause voltage sags, especially during startup.

5. 5

   If external voltage is stable, verify the inverter's internal L2 voltage measurement offset parameter (e.g., P_AI_L2_Volt_Offset) for potential misconfiguration.