AI L1L2 Over Voltage

What does F29 mean?

This fault indicates an over-voltage condition between L1 and L2 phases detected by the anti-islanding protection, exceeding the AC qualification limits. This mechanism ensures the inverter disconnects from the grid if grid power is unstable or absent, preventing dangerous backfeeding and potential damage to equipment.

• Grid L1-L2 phase-to-phase voltage exceeding the inverter's configured AC qualification limit (typically a percentage of nominal voltage).
• Grid voltage imbalance or an over-voltage condition between phases L1 and L2 caused by utility grid fluctuations or nearby heavy load changes.
• Inverter's internal L1-L2 voltage sensing circuitry experiencing drift, calibration error, or hardware malfunction.
• Anti-islanding parameter P_AI_L1L2_Volt_Max_Qual set too restrictively for the expected grid voltage envelope.

Click steps to track your progress.

1. 1

   Using a true RMS multimeter, measure and record the L1-L2 phase-to-phase voltage at the inverter's input terminals over an extended period (e.g., 30 minutes).

2. 2

   Compare the measured L1-L2 voltage values to the inverter's configured AC qualification limit parameter (e.g., P_Grid_Volt_Max_L1L2_Qual).

3. 3

   Inspect the integrity of the AC input connections for phases L1 and L2 at the inverter (e.g., Terminals L1, L2) for loose terminals or poor contact.

4. 4

   Consult the utility provider to inquire about recent grid stability, voltage anomalies, or work performed on the local distribution network.

5. 5

   If grid voltage is stable and within acceptable range, perform an internal inverter diagnostic on the voltage sensing hardware or replace the control board.