Why can’t general motors be used in plateau areas?
The main features of the plateau area are:1. Low air pressure or air density.2. The air temperature is low and the temperature changes greatly.3. The absolute humidity of the air is small.4. The solar irradiance is high. The oxygen content of the air at 5000m is only 53% of that at sea level. etc.Altitude has adverse effects on motor temperature rise, motor corona (high voltage motor) and commutation of DC motors.The following three aspects should be paid attention to: (1) The higher the altitude, the greater the temperature rise of the motor and the smaller the output power. However, when the air temperature decreases with the increase of altitude enough to compensate for the influence of altitude on temperature rise, the rated output power of the motor can remain unchanged; (2) Anti-corona measures should be taken when high-voltage motors are used on plateaus; (3) Altitude is unfavorable to the commutation of DC motors, so attention should be paid to the selection of carbon brush materials.Plateau motors refer to motors that are used at altitudes higher than 1000 meters. According to the national industry standard: JB/T7573-94 general technical conditions for electrical products under plateau environmental conditions, plateau motors are divided into many levels: they are not more than 2000 meters, 3000 meters, 4000 meters, and 5000 meters. Plateau motors operate at high altitudes, due to low air pressure, poor heat dissipation conditions, and increased losses and reduced operating efficiency. Therefore, similarly , the rated electromagnetic load and heat dissipation design of motors operating at different altitudes are different. For motors that are not high-altitude specifications, it is best to properly reduce the load to run. Otherwise, the life and performance of the motor will be affected, and even burn out in a short time.Due to the characteristics of the plateau will bring the following adverse effects on the operation of the motor, corresponding measures should be taken in the design and manufacture of the surface: 1. Causes a decrease in dielectric strength: for every 1000 meters up, the dielectric strength will decrease by 8-15%. 2. The breakdown voltage of the electrical gap decreases, so the electrical gap should be increased correspondingly according to the altitude. 3. The initial voltage of corona decreases, and anti-corona measures should be strengthened. 4. The cooling effect of the air medium decreases, the heat dissipation capacity decreases, and the temperature rise increases. For every 1000M increase, the temperature rise will increase by 3%-10%, so the temperature rise limit must be corrected.