Overtorque Detection 2

What does OL4 mean?

The OL4 alarm or fault signifies that the motor's current or torque has surpassed the Overtorque Detection 2 Level (L6-05) under conditions defined by L6-04. Depending on the L6-04 setting, the inverter might continue running (alarm) or coast to a stop (fault). This secondary detection allows for different responses to specific overtorque scenarios.

• Mechanical overload on the driven equipment (e.g., conveyor jam, pump impeller seized) causing motor current to exceed Parameter L6-05.
• Motor sizing inadequate for the application's peak torque requirements, leading to frequent overtorque conditions.
• Incorrect setting of Parameter L6-05 (Overtorque Detection 2 Level) or Parameter L6-04 (Overtorque Detection 2 Trigger Time).
• Degradation of mechanical components (e.g., bearings, gears) increasing friction and required motor torque.
• Partial short circuit in motor windings, drawing excessive current for a given mechanical load.

Click steps to track your progress.

1. 1

   1. Measure actual motor current (Amps) with a clamp meter during peak load conditions and compare to motor nameplate FLA and Parameter L6-05 setting.

2. 2

   2. Inspect the mechanical load for any binding, jams, or unusual resistance that would increase torque demand (e.g., check conveyor belt tension, pump impeller rotation).

3. 3

   3. Verify the setting of Parameter L6-05 (Overtorque Detection 2 Level) and Parameter L6-04 (Overtorque Detection 2 Trigger Time) against application requirements. Adjust L6-05 to 120-150% of motor rated torque if appropriate.

4. 4

   4. Check for excessive vibration or noise from the motor and driven equipment, indicating bearing wear or misalignment.

5. 5

   5. Perform a motor insulation resistance test (Megger test) between motor phases and to ground to detect winding degradation.

6. 6

   6. If the motor is consistently operating near its thermal limit, consider upsizing the motor or drive to match the application's torque demand.