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Nanjing refrigerant vacuum filling machine Jinan Lirui electric high-quality features

Nanjing refrigerant vacuum filling machine Jinan Lirui electric high-quality features

source network release time: 2:04 this classification information is released by the user

the induced current of induction is usually relatively small and will not have serious consequences. Some on-site use of frequency converters to control motors, which will cause leakage problems in Taiyuan quantitative filling machines, The leakage voltage varies from tens of volts to 200 volts. In view of this problem, here is a theoretical analysis and explanation of the causes of this fault, as follows: the ground wires of frequency converter, Weichuang frequency converter, soft starter frequency converter control cabinet, PLC control cabinet and motor frequency converter frame are connected together, so that they are at the same potential, and are absorbed and discharged through the induction surge filter circuit inside the frequency converter, The induced voltage is greatly reduced, so that the voltage of the induced electricity generated by the rotation of the motor relative to the ground (i.e. the ground) of the power supply is also greatly reduced, so that people will not feel energized after touching. In addition

if there are multiple frequency converters controlling the operation of the motor on site, and it is not convenient to install multiple inductive surge filters, it is not necessarily required that each frequency converter should be equipped with an inductive surge filter, or only one or two inductive surge filters can be connected, and the grounding terminal of the filter should be connected with the grounding terminal of several frequency converters on site, and the grounding terminal equipment frame of the motor on site, How to solve the three interference problems of frequency converter? The interference of the frequency converter to the microcomputer control board. In the control system using the frequency converter, the microcomputer or PLC is mostly used for control. In the process of system design or transformation, we must pay attention to the interference of the frequency converter to the good atmosphere of "everyone has something to do" in the microcomputer control board. Because the microcomputer control board designed by the user - Sichuan quantitative filling machine general process level is poor, which does not meet the EMC international standard, after using the frequency converter, Conducted and radiated interference

often leads to abnormal operation of the control system, so necessary measures need to be taken. The grounding wire of strong current control systems such as well grounded motors must be reliably grounded through the grounding busbar, the shielding ground of the microcomputer control board, * separate grounding. For some occasions that will be forced to use in the logistics industry with serious interference, it is recommended to connect the shielding layer of the sensor i/o interface with the control ground of the control board, Adding EMI filters to the input power supply of the microcomputer control board, common mode inductors, high-frequency magnetic rings and other low-cost devices can effectively suppress conducted interference. In addition, in cases of serious radiation interference, such as the presence of GSM or PHS stations around, the microcomputer control board can be shielded by adding a metal shield, and the frequency converter input can be equipped with EMI filters

it can effectively suppress the conducted interference of the frequency converter to the electricity. Adding input AC and DC reactors ll can improve the power factor and reduce harmonic pollution. The comprehensive effect is good. In some occasions where the distance between the motor and the frequency converter exceeds m, There are more ways to open the cross packing box at the side of the frequency converter and it is more convenient to operate the flow output reactor l to solve the leakage current protection caused by the distribution parameters of the output wire to the ground and reduce the radiation interference to the outside. An effective method is to use the method of threading steel pipes or shielding cables, and connect the steel pipe shell or cable shielding layer with the earth can Nanjing refrigerant vacuum filling machine. Please note, When the AC output reactor L is not added, if the method of steel pipe threading or shielded cable is used to increase the distributed capacitance of the output to the ground, overcurrent is easy to occur. Of course, in practice, only one or several methods are generally adopted

conduct electrical shielding and isolation of analog sensor detection input and analog control signal. In the design process of the control system composed of frequency converter, it is recommended not to use analog control as far as possible, especially when the control distance is greater than m and is installed across the control cabinet, because the frequency converter generally has multi-stage speed setting switch frequency input and output, which can meet the requirements. If analog control is not required, It is recommended to use shielded cables and realize a remote point grounding on the sensor side or frequency converter side. If the interference is still serious and dc/dc isolation measures need to be implemented, standard dc/dc modules can be used, or v/f conversion, optical coupling isolation and frequency setting input methods can be used

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