Precautions for motor reducers in high-temperature environments

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0.37KW motor, operating at an ambient temperature of 80°C (hot rolling mill conditions in an oven), 

experienced the following issues: the motor insulation melted, the plastic fan blades melted, 

and the bearing lubricating oil was physically vaporized by the high temperature, 

causing it to dry out, resulting in seizure and blackening of the copper wires. Generally, 

ordinary three-phase asynchronous motors are safe

 to operate in ambient temperatures between -20°C and 40°C. 

If the ambient temperature exceeds 50°C, 

a custom-made high-temperature resistant motor is required.

Motors naturally experience a temperature rise during operation, typically around 70°C. Therefore, 

the internal temperature limit of a motor is approximately 160°C-170°C. 

At an ambient temperature of 60°C, 

the derating temperature of the motor is typically around 0.82°C.

Improvement solutions: 1. Upgrade the motor's insulation class from F to H.

2. Replace the motor bearings with sealed high-temperature resistant bearings.

3. Replace the motor's plastic cooling fan with a metal fan, such as an aluminum alloy fan or an iron fan.

4. Due to power loss in high-temperature environments 

(ambient temperature > 50 degrees Celsius) or high-altitude environments 

(> 1 km), the motor needs to be derated. The motor power needs 

to be increased to achieve the actual operating power of 370W.

5. Inadequate motor dynamic balance can cause vibration, 

which may be normal at low speeds but not at high speeds.

6. Worn motor bearings, lack of lubrication, 

or improper assembly during repair or installation can cause significant rotor eccentricity, 

leading to friction between the stator and rotor, which can also cause vibration.

7. Foreign objects inside the motor, or broken bars in the squirrel-cage rotor, can cause abnormal noise and vibration.