Speed Deviation

What does dEv mean?

The drive detected a significant deviation between the commanded speed reference and the actual detected speed, exceeding the set threshold (F1-10) for longer than the specified delay (F1-11). This indicates a problem with the motor's ability to follow the speed command, potentially leading to process disruption, mechanical stress, or loss of control.

• Mechanical overload or jam in the driven machinery preventing the motor from reaching commanded speed.
• Incorrectly set speed feedback parameters (e.g., F1-10 [Deviation Detection Level], F1-11 [Deviation Detection Delay]).
• Faulty or miscalibrated speed feedback device (e.g., encoder, resolver) providing inaccurate actual speed data.
• Loose coupling between the motor and the load, or between the motor and the feedback device (encoder shaft slip).
• Insufficient motor torque to accelerate or maintain speed due to wrong motor parameters (e.g., P2-01 [Motor Rated Current]) or undersized motor.

Click steps to track your progress.

1. 1

   1. Verify the mechanical load is free to move and not jammed, manually rotating the shaft if safe.

2. 2

   2. Adjust parameter F1-10 (Speed Deviation Detection Level) and F1-11 (Deviation Detection Delay) according to application requirements.

3. 3

   3. Confirm the motor nameplate data (e.g., rated current, rated speed) is correctly entered in parameters P2-01 to P2-06.

4. 4

   4. Test the encoder or resolver feedback signal by monitoring actual speed (e.g., U1-01 [Output Frequency], U1-03 [Motor Speed]) while commanding a speed.

5. 5

   5. Inspect the encoder/resolver mounting and coupling for looseness, damage, or slippage.

6. 6

   6. Perform an auto-tune procedure (e.g., setting parameter P0-02 to "1") to optimize motor control parameters.