F556 torque proving fault in ABB DCS800 drive indicate that the drive has failed to verify the motor's torque during a torque proving procedure.

Torque proving is a process where the drive attempts to produce a specific torque level and then verifies that the actual torque output matches the commanded value.

1. Inspect the motor coupling and load for any misalignment, damage, or excessive wear.
2. Ensure that the motor and load are securely mounted.
3. Check the wiring between the drive and the motor for loose connections or damage.
4. Ensure that the motor power supply is adequate.
5. Restarting the drive can sometimes resolve temporary software issues.