ULF
Process Underload Fault (Torque)
Schneider Electric · Altivar Machine ATV320 Variable Speed Drive
What does ULF mean?
A torque underload detected fault. This indicates that the motor is operating with significantly less load than expected, potentially pointing to a mechanical failure (e.g., broken belt, pump cavitation) or a material flow issue. While not immediately damaging, it signals an abnormal process condition.
Additional Steps
Steps 1–2 are listed in Priority Fix.
- 3
Verify the underload threshold parameter in the drive configuration.
- 4
Ensure the motor is correctly sized for the application, and the expected load is present.
Source: Schneider Electric Altivar Machine ATV320 Variable Speed Drive
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