Overtorque Detection 2

What does oL4 mean?

This fault triggers when the drive's output current surpasses the level set in L6-05 for longer than the time specified in L6-06. Similar to oL3, it points to a machine issue, such as a locked rotor or improperly set load parameters. Persistent overtorque can lead to mechanical strain, premature equipment wear, or even motor damage.

• Severe mechanical jam or locked rotor condition in the driven equipment.
• Rapid deceleration rate (e.g., C1-02) set too fast, causing regenerative braking current to exceed limits, especially with large inertia loads.
• Incorrect overtorque detection level (L6-05) set too low, or overtorque detection time (L6-06) set too short.
• Motor braking circuit (if external brake resistor is used) malfunctioning or resistor value incorrect (e.g., R1-01).
• Internal short circuit within the motor windings leading to high current draw.

Click steps to track your progress.

1. 1

   1. Isolate the motor from the mechanical load and attempt to run the motor unloaded to distinguish motor/drive issue from mechanical load issue.

2. 2

   2. Monitor the drive's output current (e.g., U1-06) and the motor speed (e.g., U1-01) just before the fault occurs.

3. 3

   3. Increase parameter L6-05 (Overtorque Detection 2 Level) or L6-06 (Overtorque Detection 2 Time) in small increments if no mechanical issue is found.

4. 4

   4. If using a braking resistor, verify its resistance with an ohmmeter and check parameter R1-01 (Braking Resistor Ohms) matches.

5. 5

   5. Adjust deceleration time parameter C1-02 to a longer duration to reduce peak braking current demands.

6. 6

   6. Measure the resistance between each motor phase winding (U-V, V-W, W-U) with a multimeter (power off) and compare to specifications.