Cause: AFE Bus unbalancing comes when an imbalance in the direct current (DC) link voltage within the drive's power electronics. This imbalance can occur due to various reasons and can potentially harm the drive if not addressed promptly.

"ObF2" fault in Schneider ATV950 drive indicate "AFE Bus unbalancing" issue. This means the drive is operating with a non-linear load, the current drawn by each phase might not be equal, causing DC link voltage imbalance.

Follow theses steps to correct the fault:

1. Check Load Characteristics: Ensure the load connected to the drive is linear and balanced. If the load is non-linear, consider using input reactors or filters to improve power quality.
2. Verify Drive Parameters: Review and adjust drive parameters related to current sharing, DC bus voltage control, and other relevant settings.
3. Inspect Power Supply: Check for voltage imbalances or fluctuations in the input power supply.
4. Monitor Drive Temperatures: Excessive temperatures in the power stage components might indicate hardware issues.
5. Check Motor Condition: Verify the motor's winding resistance and current draw for any imbalances.