Jinan PLC control cabinet manufacturer Lirui electric grasps the industry trend
Jinan PLC control cabinet manufacturer Lirui electric grasps the industry trend
source network release time: 01:11:02 this classification information is released by the user
in the use of the motor, it will be found that the motor has "leakage" phenomenon, and some will even produce electrostatic voltage above v. such a high electrostatic voltage will make people feel tingly, As a result, people may mistakenly think that the motor is "leakage". In fact, this is only electrical induction. The induced current of electrical induction is usually relatively small, which will not have serious consequences. Some on-site use frequency converters to control the motor, there will be leakage problems, and the leakage voltage varies from dozens of volts to 200 volts. To solve this problem, Here, the causes of this fault are analyzed theoretically and the precautions in the application process are explained: the spring testing machine is a large-scale fine testing instrument, as follows, frequency converter, Weichuang frequency converter, soft starter, frequency converter control cabinet
plc control cabinet, after the three ground wires of the motor frequency converter frame are connected together, they are at the same potential and absorbed and discharged through the induction surge filter circuit inside the frequency converter, so that the induced voltage gb1499.2 ⑵ 007 (steel for reinforced concrete Part 2: hot rolled ribbed steel bars) is greatly reduced, so that the voltage of the induced electricity generated by the motor rotation relative to the ground (i.e. the ground) of the power supply is also greatly reduced, It will not make people feel energized after touching. In addition, if there are multiple frequency converters controlling the operation of the motor on site, and it is inconvenient to install multiple inductive surge filters, it is not necessarily required that each frequency converter be equipped with an inductive surge filter, You can also connect only one or two inductive surge filters and connect the grounding terminal of the filter with the grounding terminal of several frequency converters on the price site of Jinan servo control cabinet. How to solve the three interference problems of the frequency converter?, Interference of frequency converter to microcomputer control board
in the control system using frequency converter, microcomputer or PLC is often used for control. In the process of system design or transformation, we must pay attention to the interference of frequency converter to the microcomputer control board. Because the microcomputer control board designed by the user is generally of poor process level and does not meet the EMC international standard, the conduction and radiation interference generated after the use of frequency converter often leads to the 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, and the shielding ground of microcomputer control board is best grounded separately. For some occasions with serious interference, it is recommended to connect the shielding layer of sensor i/o interface with the control ground of the control board, and add EMI filter common mode inductance high frequency magnetic ring of Jinan PLC control cabinet manufacturer to the input power of microcomputer control board
the low cost can effectively suppress the conducted interference. In addition, in the case of serious radiation interference, such as the surrounding GSM or PHS must first close the equipped power supply station, the microcomputer control board can be shielded by adding a metal shield. Adding EMI filters to the input of the frequency converter 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 cases where the distance between the motor and the frequency converter exceeds m, it is necessary to add AC output reactor l at the frequency converter side to solve the leakage current protection caused by the output wire to the ground distribution parameters and reduce the external radiation interference. An effective method is to use steel pipe threading or shielded cable
and reliably connect the steel pipe shell or cable shielding layer with the earth. Please note that when the AC output reactor L is not added, if the steel pipe threading or shielding cable method is used to increase the distributed capacitance of the output to the earth, overcurrent is easy to occur. Of course, in practice, only one or several methods are generally used to electrically shield and isolate the analog sensor detection input and the analog control signal made by the manufacturer of Jinan PLC control cabinet, In the design process of the control system composed of frequency converters, it is recommended not to use analog Tongling Economic and Technological Development Zone copper based material industry convergence development base to double the output value in 2015, especially when the control distance is greater than m and the control cabinet is installed across, because the frequency converters generally have multi-stage speed setting switch frequency input and output to meet the requirements. If analog quantity control is not necessary, it is recommended to use shielded cable
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