Automatic Motor Tuning (AMT) failure

What does AMT tuning fail mean?

This alarm indicates that the Automatic Motor Tuning (AMT) process, which identifies motor parameters for optimal control, has failed. This can happen due to incorrect motor wiring, mechanical issues, or unsuitable motor characteristics for the tuning process.

• Incorrect motor nameplate data (e.g., rated current P1-50, rated voltage P1-51, rated frequency P1-52, rated speed P1-53) entered into the drive's parameters.
• Motor not connected to the drive, or motor wiring (U, V, W) is incorrect or has a high resistance connection.
• Motor is mechanically jammed, overloaded, or connected to a load that prevents free rotation during the tuning process.
• Drive output filter (e.g., dV/dt filter, sine wave filter) connected between the drive and motor, interfering with impedance measurement.
• Excessive cable length between drive and motor, causing significant voltage drop or inductive effects that skew tuning results.

Click steps to track your progress.

1. 1

   Verify all motor nameplate data (rated current, voltage, frequency, speed, power factor) entered in drive parameters (e.g., P1-50 to P1-55) is accurate.

2. 2

   Ensure the motor is correctly wired to the drive's output terminals (U, V, W) and that all connections are tight and making good contact.

3. 3

   Confirm that the motor is mechanically uncoupled or able to rotate freely without significant load during the AMT process.

4. 4

   If a motor output filter is installed, temporarily bypass or disconnect it for the duration of the AMT process, if permissible by system design.

5. 5

   Measure the resistance of each motor phase winding (U-V, V-W, W-U) with a multimeter to check for open circuits or significant imbalances.

6. 6

   Check motor insulation resistance from each phase to ground (using a megohmmeter) to ensure no ground faults are present which could interfere with tuning.