Speed Deviation
Yaskawa · J1000 AC Drive
What does dEv mean?
This minor fault occurs when the deviation between the speed reference and the actual speed feedback (typically from a PG option card) exceeds the threshold set in F1-10 for a duration longer than F1-11. Common causes include excessive load, improperly set acceleration/deceleration times, mechanical lock-ups, or incorrect parameter scaling. Failure to resolve this can lead to unstable motor operation, mechanical stress, or an inability to maintain desired process speeds.
Complete Troubleshooting Guide
- 1
Reduce the load on the motor if it is determined to be too heavy.
- 2
Increase the acceleration and deceleration times (C1-01 through C1-08) to allow the motor more time to reach target speeds.
- 3
Inspect the machine for any mechanical lock-ups or obstructions that prevent free movement.
- 4
Verify and adjust the settings of parameters F1-10 (speed deviation threshold) and F1-11 (deviation time limit).
- 5
If using terminal RP for speed feedback, ensure H6-02 is set to the correct speed feedback signal frequency at maximum motor speed and adjust H6-03 to H6-05 as needed. Confirm the motor brake is releasing properly and not engaging unexpectedly.