Frequency conversion motor with load test run - Solutions - Huaqiang Electronic Network

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Manually operate the stop button on the inverter panel and closely observe the motor's running process as well as the inverter's display screen to check for any signs of abnormal behavior. If the inverter triggers an overcurrent protection during the start-up or stop of the motor, it’s necessary to reset the acceleration and deceleration time settings. The motor's acceleration and deceleration performance is influenced by the torque available during these phases, and the rate at which the inverter changes frequency during start-up and braking is typically set by the user. However, if the motor’s inertia or load conditions change, adjusting the speed according to the preset frequency change rate may result in insufficient acceleration torque, causing the motor to stall—meaning the motor speed does not match the inverter’s output frequency. This mismatch can lead to overcurrent or overvoltage issues. Therefore, it’s crucial to adjust the acceleration and deceleration times based on the motor's inertia and load characteristics to ensure the inverter's frequency change rate aligns with the motor's speed change rate.

When verifying the reasonableness of these settings, it's common to begin by selecting the acceleration and deceleration times based on experience. If overcurrent occurs during startup, consider increasing the acceleration time slightly. Similarly, if overcurrent happens during braking, extend the deceleration time accordingly. However, the acceleration and deceleration times should not be set too long, as this can negatively impact production efficiency, especially when frequent starts and stops are required.

If the inverter continues to trigger protection after a short period, try modifying the start/stop curve from a straight line to an S-shaped or U-shaped curve, or even an anti-U-shaped curve. For motors with significant load inertia, longer start-stop times may be necessary, and the run curve type should be adjusted based on the specific load characteristics.

If the inverter still experiences operational faults, consider increasing the maximum current protection threshold. However, never disable the protection entirely—always leave at least a 10% to 20% margin for safety. If the issue persists, it may be necessary to replace the inverter with a higher power model to better handle the load requirements.