Motor Overload

What does OLF mean?

This fault indicates that the motor is drawing excessive current, exceeding its thermal protection limits. This can be caused by a mechanical overload on the motor or incorrect configuration of the motor's thermal current parameter (ItH) or stator resistance (rSC). Prolonged operation under overload can lead to motor winding damage or premature failure.

• Persistent mechanical overload on the driven equipment (e.g., jammed bearings, binding gears, excessive fluid viscosity).
• Incorrect motor rated current (Parameter P2-01) entered into the drive, leading to an inaccurate thermal model.
• Motor thermal protection parameters (e.g., P5-03 Motor thermal time constant, P5-04 Motor PTC/NTC enable) are not correctly configured for the motor.
• Acceleration/deceleration times (P1-02, P1-03) are too short for the inertia of the connected load, causing high transient currents.
• Insufficient motor sizing for the application's continuous power requirements or peak load demands.

Click steps to track your progress.

1. 1

   1. Disconnect the motor from the mechanical load and perform a free-run test. Measure motor current on output terminals U, V, W (should be motor no-load current).

2. 2

   2. Inspect the mechanical system (e.g., pump, fan, conveyor, gearbox) for any binding, excessive friction, or blockages that could overload the motor.

3. 3

   3. Verify that the motor rated current (Parameter P2-01) in the drive matches the actual motor nameplate current rating. Correct if necessary.

4. 4

   4. Check Parameter P5-03 (Motor Thermal Time Constant) and P5-04 (Motor PTC/NTC Enable) settings to ensure they correspond to the motor's thermal characteristics.

5. 5

   5. Increase the acceleration time (Parameter P1-02) and deceleration time (Parameter P1-03) to reduce current peaks during speed changes.