Motor temperature

P=UI; the output power of the motor remains constant. When the voltage U decreases, the current I increases. The resistance R of the motor’s windings is a constant value, and the heat generated Q is given by Q=I*I*R. Therefore. . . . . .

If the voltage is too low by more than 10%, it will increase the current flowing through the motor, raise the temperature of the coils; in severe cases, this can cause the mechanical equipment to stop operating or fail to start, and may even lead to the destruction of the motor. 　　Dangers of operating at low voltage: 1. Burning out the motor. If the voltage is too low by more than 10%, it will increase the current flowing through the motor, raise the temperature of the coils; in severe cases, this can cause the mechanical equipment to stop operating or fail to start, and may even lead to the destruction of the motor. 　　2. The light is dim. A 5% decrease in voltage results in an 18% reduction in the illuminance of ordinary light bulbs ； Voltage drops by 10%, illuminance drops by 35% ； If the voltage is reduced by 20%, the fluorescent light cannot start. 　　3. Increase line losses. When a certain amount of power is transmitted, the voltage decreases while the current increases accordingly, resulting in higher line losses. 　　4. Reduce the static and transient stability of the power system. Due to the voltage drop, the maximum transmission capacity of the line decreases accordingly, which reduces stability; excessively low voltages can lead to voltage collapse. 　　5. The generator output decreases. If the voltage drops by more than 5%, the generator output must also decrease accordingly. 　　6. Affects voltage stability. If regional reactive power compensation is insufficient, the deficit in reactive power can only be compensated by a decrease in voltage, resulting in an increasing deficit in reactive power and a decreasing voltage until collapse occurs.

According to Ohm’s law, if the voltage is low, shouldn’t the current also be low?