Frequency converter in the use of the process will inevitably appear some big and small failures, today, Jinan Inverter Maintenance Factory to share with you the causes of overload tripping frequency converter and inspection methods!
1. Reasons for overload tripping:
The characteristics of overweight mechanical load and overweight emergency are motor heating. It can be found by reading the running current on the display screen that the three-phase voltage is unbalanced, which results in excessive running current of a certain phase and overload tripping. Its characteristics are the unbalanced heating of the motor.
2. Inspection methods:
Check whether the three-phase voltage on the motor side is balanced. If the three-phase voltage on the motor side is not balanced, then check whether the actual three-phase voltage output of the converter is balanced. If it is not balanced, the problem is inside the converter.
If the output voltage of the converter is practically balanced, the problem is whether the whole connection screw has been tightened on the line from the converter to the motor. If there are contactors or other electrical appliances between the converter and the motor, it is also necessary to check whether the connection terminals of the related electrical appliances have been tightened and the contacts have been tightened. Whether the situation is good or not.
If the three-phase voltage on the motor side is balanced, we should look at the working frequency when tripping. If the working frequency is low and the vector is not used, the U/f ratio will be lowered first. If the U/f ratio can still drive the load after the fall, it shows that the original preset U/f ratio is too high and the peak value of excitation current is too large, the U/f ratio will be lowered to reduce the current if the drop lags behind. If the load is not fixed, the capacity of the converter should be increased. If the converter has the function of vector application, vector application should be adopted.
Check whether the motor is heating, if the temperature rise of the motor is not high, the first thing to check is whether the electronic thermal protection function of the frequency converter is properly preset. If the frequency converter is redundant, the preset value of the electronic thermal protection function should be relaxed.
The above is the Jinan Inverter Maintenance Factory to bring you information, to learn more about the relevant knowledge, you can pay attention to our official website!