Stall Prevention Trip

What does E.OLT mean?

This fault occurs when the inverter's output frequency drops to 1Hz due to stall prevention operation and remains at that level for 3 seconds, ultimately leading to an inverter trip. The display shows "OL" during active stall prevention. This indicates that the motor is experiencing a continuous overload condition that the stall prevention function cannot overcome. Sustained overload can lead to motor and inverter damage.

• Excessive mechanical load on the motor causing it to slow down significantly, leading to the inverter's stall prevention (current limit) to activate.
• Incorrectly set stall prevention level (e.g., Pr. 156-Pr. 159 related parameters) causing it to trip too easily under normal load.
• Motor's rated torque or power being insufficient for the application, leading to continuous overload conditions.
• Mechanical binding or jamming in the driven machinery, impeding motor rotation and increasing torque demand.
• Parameter Pr. 155 (Stall prevention operating frequency) is set too high, triggering the trip condition prematurely.

Click steps to track your progress.

1. 1

   Measure the actual motor operating current and speed under load and compare to the motor's rated specifications.

2. 2

   Inspect the mechanical system (gears, bearings, belts, shafts) for binding, excessive friction, or physical damage.

3. 3

   Review and adjust stall prevention parameters (e.g., Pr. 156, Pr. 157, Pr. 158) to ensure they are appropriate for the motor and load characteristics.

4. 4

   Increase the acceleration time (Pr. 7) to allow the motor more time to overcome inertia without stalling during startup.

5. 5

   Verify the motor parameter settings (Pr. 9, Pr. 71, Pr. 80, Pr. 81) match the actual motor nameplate data.