Overload

What does 400 mean?

This alarm indicates that a servo motor or an axis connected to the Fanuc Series 20 CNC has experienced an excessive load, exceeding its continuous rating or instantaneous peak capacity, for a duration beyond the permissible limit. This can lead to motor overheating and potential damage.

• Excessive mechanical load on the axis due to heavy cutting conditions, workpiece weight, or tooling.
• Mechanical binding, obstruction, or increased friction in the axis mechanics (e.g., worn bearings, overtightened components).
• Incorrect servo motor parameters (e.g., acceleration/deceleration times too short, current limits set too low).
• Malfunctioning servo motor (e.g., shorted windings, worn bearings).
• Issue with the servo amplifier's current monitoring or control circuitry.

Click steps to track your progress.

1. 1

   Inspect the mechanical system for binding, obstructions, or excessive friction. Manually move the axis to check for smooth operation throughout its travel.

2. 2

   Verify servo motor parameters, specifically current limits, acceleration/deceleration settings, and overload protection thresholds, against the machine's electrical schematics and specifications.

3. 3

   Monitor the actual motor current and torque load using the CNC diagnostic screen during operation to identify peak load conditions.

4. 4

   Check the motor cooling fan for proper operation and ensure no dust or debris is obstructing airflow.

5. 5

   Test motor windings for short circuits or ground faults, and measure phase-to-phase resistance with a multimeter.