The selection of frequency converter is really important, because if the selection is not appropriate, it will cause waste of time and money, and production accidents and personnel damage.
Small edition here and you talk about low-voltage inverter fast selection method, for reference.
First, according to the classification and selection of frequency converter
1. The frequency converter can be divided into general frequency converter and special frequency converter.
2. General purpose inverter is mainly used in: general fan and pump type load, mechanical load, load requiring high overload, etc.
3. Special frequency converter is mainly used in: special fan pump (refer to frequency converter driving multiple fans or pumps) load, elevator type load, tension control load, EPS type load, dust and moisture proof load, textile type load, pumping unit type load, explosion-proof type load, etc.
Second, model selection according to parameters
1. Generally, the model of frequency converter is defined according to the number + power of each manufacturer. For example, the model of frequency converter of a certain brand is *** - 011g / 015p, in which G represents heavy load constant torque and adapts to 11kw heavy load or constant torque load; P represents light load and adapts to 15kw light load series load.
2. The accurate method of selecting frequency converter is based on the actual rated current of motor, and the rated power of motor can only be used as reference.
3. If the distance between the frequency converter and the motor is far, it is recommended to install an output reactor if the distance is more than 100m, and the power of the frequency converter should be selected by amplifying the first gear.
4. When the frequency converter is used to control several motors in parallel, it must be considered that the total length of the motor cable is within the allowable range of the frequency converter.
5. When selecting the frequency converter for high-speed motor, it should be slightly larger than that for ordinary motor.
6. When the explosion-proof motor is driven, the explosion-proof special frequency converter shall be selected.
7. For the load with large torque fluctuation such as compressor and vibrator and the peak load such as oil pressure pump, it is necessary to understand the power frequency operation and select the frequency converter with rated output current greater than its maximum current.
8. Single phase motors are not suitable for inverter drive.
Third, select the type according to the use environment
1. Influence of ambient temperature on frequency converter: when selecting the frequency converter, it is necessary to consider that the ambient temperature is generally - 10 ~ 40 ° C. if the temperature of the working environment is higher than 40 ° C, the frequency converter shall be used with 5% derating for every 1 ° C increase, and external forced heat dissipation must be added.
2. Influence of humidity on frequency converter: when selecting frequency converter, if the humidity is lower than 90%, the relative humidity of air is less than or equal to 90%, without condensation. If the humidity is too high and the humidity changes greatly, the internal part of the frequency converter is prone to condensation, then the insulation performance will be greatly reduced, and even lead to short circuit. The special frequency converter for preventing humidity shall be selected for this kind of working condition
3. Influence of altitude on frequency converter: the frequency converter can output rated power when installed below 1000m altitude. When the altitude is over 1000m, the output power will decrease; when the set carrier frequency is above the factory value, the converter needs to be derated 5% for every 1kHz increase.
4. Influence of dust on frequency converter: in the case of metal conductive dust, the conductive dust will invade the inside of frequency converter, which is easy to cause short circuit of the internal circuit of frequency converter and burn down the frequency converter in serious cases. Therefore, in the case of dust production and operation, this kind of working condition should choose a special inverter for dust prevention, which can prevent the dust from entering and avoid the burning of the motor.
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