Motor temperature and temperature rise：
Generally speaking, the temperature range of the motor is appropriate, which depends on the insulation level of the motor. If it is Class A, then the ambient temperature is 40°C and the temperature of the motor's shell should be less than 60°C.
 
The limit temperature of the motor is also closely related to the insulation class of the motor. For example, the limit working temperature of class A is 105°C, while the maximum allowable working temperature of class A is 90°C.
 
In the case of the motor under the rated load, the temperature of the shell should not be higher than 80 degrees, normally around 60 or 70 degrees, except for the water pump motor.
The relationship between temperature rise and temperature and other factors:
 
1. When the temperature drops, the temperature rise of the normal motor will slightly decrease. This is because the winding resistance R decreases and the copper loss decreases. When the temperature drops by 1℃, R drops by about 0.4%.
 
2. For self-cooling motors, temperature changes have a greater impact on large motors and enclosed motors. For every 10°C increase in ambient temperature, the temperature rise will increase by 1.5 to 3°C because the copper loss of the winding increases with the temperature rise.
 
3. When the air humidity increases by 10%, the temperature rise can be reduced by 0.07～0.38℃, with an average of 0.19℃ due to the improvement of heat conduction.
 
4. The altitude also affects the temperature rise. The altitude is 1000m as the standard. For every 100m liter, the temperature rise will increase by 1% of the temperature rise limit value.