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1. Manually operate the running stop key on the panel of the inverter, observe the process of the motor running and stopping and the display window of the inverter to see if there is any abnormal phenomenon.

2. If activated. In the process of stopping the motor, the inverter has an overcurrent protection action, and the acceleration and deceleration time should be reset. The acceleration of the motor during acceleration and deceleration depends on the acceleration torque, while the frequency change rate of the frequency converter during startup and braking is set by the user. If the moment of inertia of the motor or the load of the motor changes, when the speed is increased or decelerated according to the preset frequency change rate, the acceleration torque may be insufficient, which may cause the motor to stall, that is, the motor speed is not coordinated with the output frequency of the inverter, resulting in excessive current or overvoltage. Therefore, it is necessary to set the acceleration and deceleration time reasonably according to the moment of inertia of the motor and the load, so that the frequency change rate of the inverter can be coordinated with the motor speed change rate. The way to check whether this setting is reasonable is to first select the acceleration and deceleration time according to experience. If overcurrent occurs during startup, the acceleration time can be extended appropriately; if overcurrent occurs during braking, then Appropriately extend the deceleration time. On the other hand, the acceleration and deceleration time should not be set too long, as it will affect the production efficiency, especially when starting and braking frequently.

3. If the inverter is still protected within the limited time, the start/stop operation curve should be changed from a straight line to an S-shaped, U-shaped line or reversed S-shaped, reversed U-shaped line. When the load inertia of the motor is large, a longer start and stop time should be used, and the type of operation curve should be set according to its load characteristics.
4. If the inverter still has running faults, try to increase the protection value of the maximum current, but the protection cannot be canceled, and at least 10%-20% protection margin should be left.
5. If the frequency converter still fails to operate, replace it with a higher power frequency converter.
6. If the motor driven by the frequency converter cannot reach the preset speed during startup, there may be two situations:
(1) Electromechanical resonance occurs in the system, which can be judged from the sound of the motor running. The resonance point can be avoided by setting the frequency jump value. Generally, the frequency converter can set three jump points. When the frequency converter controlled by V/f drives the asynchronous motor, the current and speed of the motor will oscillate in certain frequency bands. In serious cases, the system cannot operate, and even the over-current protection occurs during the acceleration process so that the motor cannot start normally. It is more serious when the load is light or the moment of inertia is small. Ordinary inverters are equipped with a frequency jump function, and the user can set the jump point and jump width on the V/f curve according to the frequency point where the system oscillates. When the motor accelerates, it can automatically skip these frequency bands to ensure the normal operation of the system.(2) The torque output capacity of the motor is not enough. Different brands of inverters have different factory parameter settings. Under the same conditions, the load capacity of the motor is different, and the load capacity of the motor may also be different due to different control methods of the inverter; or Due to the different output efficiency of the system, the load capacity will be different. For this case, increase the value of Torque Boost. If it cannot be achieved, use the manual torque boost function, do not set it too high, the temperature rise of the motor will increase at this time. If it still doesn't work, you should use a new control method. For example, the Hitachi inverter adopts the method of constant V/f ratio. When the start-up fails to meet the requirements, use the speed sensorless space vector control method, which has a larger torque output. ability. For fan and pump loads, the curve value of derating torque should be reduced.

4. The frequency converter is connected with the upper computer for system debugging
After the manual basic setting is completed, if there is an upper computer in the system, connect the control wire of the inverter directly to the upper computer control wire, and change the operation mode of the inverter to terminal control. According to the needs of the upper computer system, set the range 0-5V or 0-10V of the inverter receiving frequency signal terminal, and the response speed of the inverter to the analog frequency signal sampling. If additional monitor headers are needed, select the monitor value of the analog output and adjust the range of the inverter output monitor value terminal.