Overtorque

What does OL3 mean?

An OL3 condition indicates an overtorque situation where the motor's output torque exceeds the configured L6-02 level for the duration set in L6-03. This can be set as either an alarm or a fault and can be detected continuously or only when at speed agreement. It typically signifies a jam, excessive mechanical load, or an obstruction in the driven equipment. Unresolved overtorque can lead to motor overheating, mechanical damage, or drive trip.

• Mechanical overload on the driven equipment (e.g., jammed conveyor, seized bearing, excessive material in a crusher), requiring torque beyond the motor's capability.
• Incorrect setting of parameter L6-02 (Overtorque Detection Level) or L6-03 (Overtorque Detection Time), making the detection too sensitive or too fast.
• Motor operating at a very low speed or with insufficient cooling, reducing its torque capability and causing it to appear overloaded at lower actual loads.
• Failure of the mechanical brake or a backstop on the load, leading to motor having to hold or drive an unexpected load.
• Incorrect motor parameters (e.g., E1-01, E1-02) entered into the drive, leading to an inaccurate calculation of motor torque.

Click steps to track your progress.

1. 1

   Visually inspect the driven machine for any mechanical binding, obstructions, or damage that could be increasing the load on the motor.

2. 2

   Using a clamp-on ammeter, measure the motor's actual operating current (e.g., on U/T1, V/T2, W/T3) and compare it to the motor's rated current (E1-01) and the OL3 detection level (L6-02).

3. 3

   Temporarily increase the parameter L6-03 (Overtorque Detection Time) to a higher value (e.g., 5-10 seconds) to determine if the overtorque condition is momentary.

4. 4

   Confirm that the drive's motor data parameters (E1-01, E1-02, E1-03) accurately match the motor's nameplate information.

5. 5

   Verify the integrity of the power transmission components (e.g., belts, pulleys, gears, couplings) for wear, misalignment, or damage.