For motor manufacturers, why are the powers of motors in the same center under high conditions so different?

　　Motor manufacturers clarify the differences through the heat dissipation conditions of the different protection grades.Use the most common comparison of IP23 and IP54 motors: under the same center height condition, the power of IP23 motors is larger than that of IP54 motors, and some are even outrageous.Why is this? The heat dissipation conditions are too poor.

　　The heat dissipation of IP23 motor windings is basically carried out by directly exchanging heat with the outside world.The prevailing wind path is designed as follows: the cold atmosphere enters through the windows at both ends of the motor and is directed to the feverish part. After receiving the heat generated by the motor, it exits from the window in the middle of the base and dissipates in the surrounding conditions.The fever parts of the motor almost completely fight with the heat dissipation medium, direct heat transfer and high heat exchange efficiency.If the unobstructed path of the heat dissipation medium atmosphere is fair, the product of the motor winding thermal load or the ampere-turns (electrical load) on the circumference of the unit length coil and the winding current density can be selected to be very high, which means that the electric power that the unit material can carry is required. Large, the motor volume can be greatly reduced.

　　However, the magnetic load will not change much due to the limitation of the saturation of the magnetic material. The closed motor with IP44 and higher protection level is compared with the open motor with IP23 and other different protection levels, and the thermal load can only reach 1/ 2 Your degree, and it is necessary to install an electric fan and a wind hood that enhance the heat dissipation of the appearance of the cabinet. The method of ventilation and heat dissipation is to exchange heat between the appearance of the cabinet and the outside atmosphere. The unit volume carrying power is also much smaller.Therefore, under the condition of concentric height, the power of the protective motor is larger than that of the closed motor, and the ventilation noise is also small.

　　The motor selection should be based on the detailed operating conditions first, and the protective motor of the same power should have a small frame size, self-made value and high reliability, but the operating conditions are bad and still cannot be selected.However, there are many confusing environments, which require customers to make appropriate requirements for protection, not to protect too much, and to meet the requirements of reliable operation under specific working conditions. The above-mentioned related common sense is the theoretical basis for correct measurement and selection.