Undertorque Detection 1
Yaskawa · F7 Drive
Hva betyr UL3 ?
The drive detected that its output current was continuously below the threshold set in L6-02 for longer than the time specified in L6-03, when L6-01 was configured for undertorque detection. This fault indicates that the connected motor is operating under an unexpectedly low load, potentially due to a mechanical issue or process change.
Vanlige årsaker
- Mechanical decoupling of the motor from its load (e.g., broken belt, coupling failure, pump running dry).
- Process material flow stoppage (e.g., conveyor belt empty, fan damper fully closed).
- Undertorque detection level (L6-02) set too high, triggering even under normal light load conditions.
- Undertorque detection delay time (L6-03) set too short, causing nuisance trips during transient low current.
- Drive's internal current measurement inaccuracy or drift.
Reparasjonssteg & Sjekkliste
Klikk på steg for å spore fremgangen.
- 1
1. Visually inspect the mechanical coupling between the motor and its load (e.g., belt tension, coupling integrity).
- 2
2. Confirm the process being driven by the motor is operating normally and not in a no-load or extremely light-load condition.
- 3
3. Use a clamp-on ammeter to measure the actual motor output current during normal light-load operation and compare it to the L6-02 setting.
- 4
4. Adjust parameter L6-02 (Undertorque Detection Level 1) to a lower, more appropriate current threshold that reflects actual light-load operation.
- 5
5. Increase parameter L6-03 (Undertorque Detection Time 1) to allow for temporary low current conditions without tripping the fault.