Siemens inverter is commonly used in the control of fans and pumps loads, by changing the frequency and voltage size, so as to control the motor to run at different speeds, to achieve the effect of flexible control. In the use of frequency converter, users need to pay attention to the reasonable use, so that the frequency converter can work normally and stably. In this paper, the following overload problem for Siemens inverter analysis, to provide users with some judgment methods.
Siemens inverter overload check method
1. Check whether the three-phase voltage on the motor side is balanced, if the three-phase voltage on the motor side is unbalanced, then check whether the three-phase voltage on the output side of the frequency converter is balanced, if it is also unbalanced, then the problem is inside the frequency converter.
If the voltage at the output side of the inverter is balanced, the problem lies in the line from the inverter to the motor, check whether all the screws at the terminal are tightened, and if there is a contactor or other electrical appliances between the inverter and the motor, check whether the terminals of the relevant electrical appliances are tightened and whether the contacts are in good contact condition.
2. Check whether the motor is hot or not, if the temperature rise of the motor is not high, then first of all, you should check whether the electronic thermal protection function of the frequency converter is reasonably preset, such as the frequency converter is still available, then you should relax the preset value of the electronic thermal protection function.
If the temperature rise of the motor is too high, and the overload is a normal overload, then the motor load is too heavy. At this time, the first should be able to appropriately increase the transmission ratio to reduce the load on the motor shaft. If you can increase, then increase the transmission ratio. If the transmission ratio can not be increased, then the motor capacity should be increased.
If the motor side of the three-phase voltage balance, you should know the operating frequency when the trip:
If the operating frequency is low, and not with vector control (or no vector control), then first reduce the U/f ratio, if the reduction can still drive the load, it means that the original preset U/f ratio is too high, and the peak value of the excitation current is too large, and the current can be reduced by reducing the U/f ratio; if the reduction does not bring the load, then the capacity of the inverter should be considered to be increased; if the frequency converter has the function of vector control, then it should be used. Vector control mode.
This paper analyses the transformer overload situation from several aspects, the user in the actual use of the process, if you encounter similar problems, you can refer to the content provided in this paper to solve. More problems are also welcome to communicate with us.