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ErrorLib — Industrial Fault Code Library

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400

Servo Motor Overheat (Estimated)

Fanuc · Alpha i series AC Servo Motor

What does 400 mean?

The servo motor has overheated, indicated by an estimated temperature exceeding safe operating limits. This suggests that the motor's operating conditions may be excessively severe, leading to thermal stress.

Common Causes

  • Motor operation conditions are too severe for the motor's thermal capacity (e.g., high duty cycle, excessive load).
  • Ambient temperature around the motor is excessively high.

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Evaluate the motor's duty cycle, load, and speed profile; reduce operating severity if possible.

  2. 2

    Verify ambient temperature around the motor does not exceed specified limits.

  3. 3

    If the alarm recurs after the motor has cooled, replace the motor or servo amplifier.

Browse all codes in this manual (60)
Verified technical data. Last updated: April 2026

Related Faults

000Power-Down Required Parameter011Zero Feedrate Specified013Maximum Feedrate Zero
Source: Fanuc Alpha i series AC Servo Motor
Open Manual (Page 226)Search more codes in this manual