Stall prevention stop

What does E.OLT mean?

This stall prevention stop fault occurs if the inverter's output frequency drops to 1Hz and remains there for 3 seconds due to active stall prevention. It indicates a prolonged and severe overload condition on the motor, which can lead to motor and inverter stress if unaddressed.

• Mechanical overload on the driven machine (e.g., jammed conveyor, seized bearing, heavy material buildup).
• Motor current exceeding the stall prevention threshold (e.g., Pr. 156 for current limit) for an extended period.
• Incorrect motor parameters (e.g., Pr. 0, Pr. 2, Pr. 3, Pr. 4) entered into the inverter, leading to inaccurate current sensing.
• Supply voltage sag below nominal, causing the motor to draw excessive current to maintain torque.
• Insufficient motor rated power for the application's torque requirements, leading to continuous overload.

Click steps to track your progress.

1. 1

   Measure the mechanical load on the driven equipment (e.g., using a torque wrench if applicable) to identify any jams or excessive resistance.

2. 2

   Verify the motor's full load current (FLC) and nameplate power are correctly entered in inverter parameters (e.g., Pr. 3, Pr. 9).

3. 3

   Monitor the inverter's output current (via display or software) during operation to identify values exceeding Pr. 9 (Motor Rated Current).

4. 4

   Increase the stall prevention operation level (e.g., Pr. 156 Stall Prevention Current Level) if the motor can tolerate higher current temporarily.

5. 5

   Confirm that the motor is receiving adequate cooling and its surface temperature is within manufacturer specifications.

6. 6

   Measure the resistance of each motor phase winding (U-V, V-W, W-U) to detect any winding shorts or open circuits.