Servo axis abnormal load detected signal

What does ABTQSV mean?

This signal indicates that a servo axis in the Fanuc i Series CNC has encountered an abnormal load condition. This typically suggests the motor is drawing excessive current, potentially leading to motor overload, drive tripping, or mechanical damage.

• Excessive mechanical load, binding, or obstruction in the servo axis movement.
• Incorrect servo tuning parameters, such as high gain or insufficient torque limit.
• Motor or servo amplifier malfunction (e.g., degraded windings, faulty encoder).
• Degraded mechanical components like bearings, lead screws, or linear guides.
• Short circuit or ground fault in the motor power cable or motor windings.

Click steps to track your progress.

1. 1

   Mechanically disconnect the motor from the load (if safe and feasible) and test the motor independently to rule out mechanical binding.

2. 2

   Inspect the mechanical system (bearings, guides, ball screw) for damage, debris, or excessive friction.

3. 3

   Monitor the actual motor current and torque via the CNC diagnostic screen to identify the specific overload condition.

4. 4

   Verify servo tuning parameters (e.g., servo gain, acceleration/deceleration times, torque limits) against the machine builder's specifications.

5. 5

   Check motor windings and power cables for short circuits or ground faults using a multimeter and insulation resistance tester.