Cause : Motor is turning faster than highest allowed speed due to incorrectly set minimum/maximum speed, insufficient braking torque or changes in load when using torque reference.

1. Check minimum/maximum speed settings, parameters 30.11 Minimum speed and 30.12 Maximum speed.

2. Check adequacy of motor braking torque.

3. Check applicability of torque control.

4. Check need for brake chopper and resistor.