Undertorque Detection 2

What does UL4 mean?

This fault triggers when the drive's output current falls below the level set in L6-05 for longer than the time specified in L6-06. Similar to UL3, it's often caused by a machine problem like a broken pulley belt or misconfigured load parameters. Ignoring this can result in undetected mechanical problems, operational inefficiencies, or unexpected stops.

• Partial load reduction in the driven machinery (e.g., conveyor belt temporarily clearing a jam).
• Reduced viscosity of material in mixing or pumping applications, lowering the required torque.
• Parameter L6-05 (Undertorque Detection Level 2) set excessively high for the application's operating range.
• Drive operating in an extended unloaded state due to process interruption or standby mode.
• Loose mechanical components causing reduced friction or load resistance.

Click steps to track your progress.

1. 1

   Inspect the driven machinery and process for any conditions that would cause a sustained reduction in load.

2. 2

   Verify L6-05 (Undertorque Detection Level 2) is set appropriately for the secondary undertorque condition.

3. 3

   Adjust L6-06 (Undertorque Detection Delay 2) to prevent nuisance trips for short-duration load changes.

4. 4

   Monitor the drive's output current (parameter U1-03) during various load conditions.

5. 5

   Check for any changes in the process material or conditions that could consistently lower torque requirements.