Mitsubishi FR-A Series- FR-A800, FR-A770/A701, FR-A700, FR-A800-E, FR-A741 Drive
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Apr 01, 2024 5:09 am
Cause : Overcurrent trip during acceleration comes when the inverter output current reaches or exceeds approximately 220% of the rated current during acceleration, the protective circuit is activated to stop the inverter output.
- Check for sudden speed acceleration.
- Check if the downward acceleration time is too long in a lift application.
- Check for output short-circuit.
- Check that the Pr.3 Base frequency setting is not 60 Hz when the motor rated frequency is 50 Hz.
- Check if the stall prevention operation level is set too high. Check if the fast-response current limit operation is disabled.
- Check that the regenerative driving is not performed frequently. (Check if the output voltage becomes larger than the V/F reference voltage at regenerative driving and overcurrent occurs due to increase in the motor current.)
- Check that the power supply for RS-485 terminal is not shorted (under vector control).
- Check that the encoder wiring and the specifications (encoder power supply, resolution, differential/ complementary) are correct.
- Check also that the motor wiring (U, V, W) is correct (under vector control).
- Check that the rotation direction is not switched from forward to reverse rotation (or from reverse to forward) during torque control under Real sensorless vector control.
- Check that the inverter capacity matches with the motor capacity. (PM sensorless vector control)
- Check if a start command is given to the inverter while the motor is coasting. (PM sensorless vector control)