Fanuc 0i Error Code 521

Fanuc CNC Minor Overtravel

Model: FANUC Series 0i / 0i Mate | Code: 521

Applicable Systems
Series 0i Series 16/18/21 Alpha Beta

Symptoms

Y axis negative overtravel detected, exceeding the negative software or hardware limit.

Possible Causes

  • The Y axis moved beyond the negative travel limit.
  • Program error or incorrect work offset.

Troubleshooting Steps

  1. Step 1: Manually move the Y axis back within the travel limit.
    Y axis moved to within limits.
  2. Step 2: Check and correct the program or offset causing the overtravel.
    Root cause identified and corrected.

How to Reset

Move the Y axis back within limits and reset to clear the alarm.

Related Fanuc Fault Codes

Source: Fanuc 0i/0iMate Alarm Code List, FANUC Corporation

Category: CNC