Excessive Speed Deviation

What does DEV mean?

This fault occurs in Flux Vector control (A1-02=3) when the actual motor speed deviates from the reference speed by more than the F1-10 setting for longer than the F1-11 time. It often indicates a locked load or an inability for the motor to follow its command. Unresolved, this can lead to poor process control, mechanical stress on the system, or motor overheating due to sustained effort.

• Motor shaft or load mechanical issue (e.g., seized bearings, broken coupling, excessive friction) preventing the motor from reaching commanded speed.
• Incorrect motor parameters (e.g., E1-01 to E1-06, P1-01) entered in the Drive, leading to inaccurate speed estimation or control.
• Encoder feedback issue (e.g., loose wiring, damaged encoder, signal noise) causing incorrect actual speed measurement.
• Motor experiencing overload condition beyond its rated torque, making it unable to maintain speed.
• Drive output current limit (C3-01) or motor torque limit (P1-08) being reached prematurely, restricting power to the motor.

Click steps to track your progress.

1. 1

   With the motor de-energized, manually attempt to rotate the motor shaft and connected load to check for binding or excessive mechanical resistance.

2. 2

   Verify all motor nameplate data (E1-01 to E1-06) is accurately entered into the Drive parameters.

3. 3

   Inspect the encoder wiring for damage or loose connections, and verify the encoder pulses per revolution (P5-14) setting is correct.

4. 4

   Monitor the Drive's output current (U1-02) during operation to identify if the motor is consistently running at or above its rated current.

5. 5

   Adjust the F1-10 (Speed Deviation Detection Level) and F1-11 (Speed Deviation Detection Time) parameters to prevent nuisance trips, then perform auto-tuning (T1-01=1).

6. 6

   Check parameters P1-08 (Torque Limit) and C3-01 (Current Limit) to ensure they are not set too low for the application's required motor torque.