Cause : Opposite rotation deceleration fault comes when the speed may not decelerate during low speed operation if the rotation direction of the speed command and the estimated speed differ when the rotation is changing from forward to reverse or from reverse to forward during torque control under Real sensorless vector control.

1. At this time, the inverter output is stopped if the rotation direction will not change, causing overload. This fault is not available in the initial status (V/F control). (It is available only during Real sensorless vector control.)
2. Check that the rotation direction is not switched from forward to reverse rotation (or from reverse to forward) during torque control under Real sensorless vector control.
3. Prevent the motor from switching the rotation direction from forward to reverse (or from reverse to forward) during torque control under Real sensorless vector control.