The electrical-related knowledge shared for you today is: how to determine the position of the frequency conversion control equipment and the motor. Everyone should understand the basic knowledge, that is, the distance between the frequency conversion control equipment and the motor should be as short as possible.

This reduces the cable's capacitance to ground and reduces the source of interference. Use shielded cables for control cables, shielded cables for power cables or use conduits for shielding from variable frequency control equipment to motors. The motor cable should be independent of other cables.

The smaller distance is 500mm. At the same time, avoid long-distance parallel routing of the motor cable and other cables, so as to reduce the electromagnetic interference caused by the rapid change of the output voltage of the frequency conversion control equipment. If the control cable and the power cable cross, you should do everything possible

Can make them cross at an angle of 90 degrees. The analog signal wires related to the frequency conversion control equipment are routed separately from the main circuit wires, even in the control cabinet.

　　Main circuit: The function of the reactor is to prevent the high-order harmonics generated by the frequency conversion control equipment from returning to the grid through the input circuit of the power supply, thereby affecting other power receiving equipment. It is necessary to decide whether to increase the frequency according to the capacity of the frequency conversion control equipment.

Reactor: The filter is installed at the output end of the frequency conversion control equipment to reduce the high-order harmonics output by the frequency conversion control equipment. When the distance between the frequency conversion control equipment and the motor is far, the filter should be installed. You can use the inverter’s own overload protection

Replace the thermal relay. The frequency conversion control equipment has manual switching of the power frequency and frequency conversion, so that the power frequency can be manually cut when the frequency conversion fails. Because the output terminal can not be applied with voltage, the solid power frequency and the frequency conversion must be interlocked. The frequency conversion control equipment itself has various guarantees

Protection function, but the lack of phase protection is not perfect, the circuit breaker plays an overload and lack of equal protection in the main circuit, the selection can be based on the capacity of the inverter.

　　The correct grounding of frequency conversion control equipment is an important means to improve system stability and suppress noise. The grounding resistance of the grounding terminal of the frequency conversion control equipment is as small as possible. The cross-section of the grounding wire is not less than 4mm and the length is not more than 5m. And change

It is better to use shielded twisted-pair cables for analog signal wires related to frequency control equipment, and use shielded three-core cables for power cables (its specifications are larger than those of ordinary motor cables) or follow the inverter's user manual. Grounding and power of variable frequency control equipment

The grounding points of the equipment are separated and cannot be grounded together. One end of the shielding layer of the signal wire is connected to the ground terminal of the inverter, and the other end is floating. There is electrical communication between the inverter and the control cabinet.