Er.909 fault in inovance IS650 servo drive indicates Motor overload warning. This means the motor is being asked to produce more torque than it is rated for, which can lead to overheating, reduced performance, and potential damage.

1. Check wirings between servo drive, servo motor and encoder according to correct wiring diagram.
2. Confirm overload characteristic of servo drive or servo motor.
3. Check whether average load rate (H0B-12) is greater than 100.0% for long time.
4. Observe whether motor vibrates and generates noise during running.