Undertorque Detection 1
Yaskawa · J1000
¿Qué significa UL3 ?
The motor current has fallen below the minimum value set for torque detection (L6-02) for longer than the allowable time (L6-03). This indicates either inappropriate parameter settings for the current load conditions or a mechanical fault on the machine side, such as a loss of load or broken coupling.
Causas comunes
- Undertorque detection level (L6-02) set too high, exceeding the actual minimum operating current.
- Undertorque detection time (L6-03) set too short, causing nuisance trips from momentary load fluctuations.
- Actual mechanical load significantly reduced or completely absent (e.g., broken belt, coupling failure).
- Incorrect current transformer (CT) ratio set in drive parameters (if external CTs are used).
- Motor parameter auto-tuning (A1-02) results are inaccurate for the connected motor.
Pasos de reparación & Lista de verificación
Haga clic en los pasos para seguir su progreso.
- 1
1. Verify that the undertorque detection level parameter (L6-02) is appropriately set based on the minimum expected load current.
- 2
2. Increase the undertorque detection time parameter (L6-03) to prevent nuisance tripping from momentary load fluctuations.
- 3
3. Inspect the mechanical system for any disconnections, broken belts, chain failures, or coupling issues in the driven equipment.
- 4
4. Monitor the actual motor output current during operation using drive diagnostics (e.g., U1-01) or an external clamp meter and compare to L6-02.
- 5
5. Check the drive's motor parameter auto-tuning results (A1-02) for accuracy, especially motor rated current (P1-02).
- 6
6. If an external current transformer is used, confirm its ratio is correctly configured in the drive parameters (if applicable).