Auto-Tuning Fault

What does -tnF mean?

This fault occurs during the auto-tuning process, indicating that the drive controller is unable to successfully tune itself to the connected motor. This is typically due to using a specialized motor or one whose power rating does not match the 'n' (nominal) or 'nld' (no-load) settings of the UFb parameter, preventing optimal motor control. Incorrect tuning can lead to inefficient operation or other motor control issues.

• Incorrect motor nameplate data (e.g., P2-01 rated current, P2-02 rated voltage, P2-03 rated frequency) entered into the drive's parameters.
• Open circuit in one of the motor stator windings, preventing accurate impedance measurement during tuning.
• Motor not connected directly to drive output (e.g., through an output filter, line reactor, or contactor) during tuning.
• Motor output cabling (U, V, W) too long or incorrect gauge, leading to excessive voltage drop during the tuning process.
• Tuning attempted with a specialized motor (e.g., reluctance motor, certain servo motors) incompatible with standard autotune algorithms.

Click steps to track your progress.

1. 1

   Verify all motor nameplate data (P2-01, P2-02, P2-03, P2-04, P2-05) matches the drive's parameter settings precisely.

2. 2

   Disconnect motor power cables (U, V, W) from the drive output terminals (T1, T2, T3) and perform a winding resistance test. Check for open phases.

3. 3

   Ensure no external devices (contactors, fuses, filters) are connected between the drive output and the motor during the tuning process.

4. 4

   Review the motor cable length. For long cable runs, consider using a drive-side line reactor or specific drive parameters for compensation.

5. 5

   If using a specialized motor, review the drive manual for specific tuning procedures or consider disabling autotuning and manually entering motor parameters.