Generally speaking, if the motor insulation level is A, the ambient temperature is 40 degree C, then the motor shell temperature should be less than 60 degree C. The core temperature rise of the winding contact (thermometer method) should not exceed the temperature rise limit of the winding insulation contact (resistance method), that is, class A is 60 degree C, class E is 75 degree C, class B is 80 degree C, class F is 100 degree C, and class H is 125 degree C. The temperature of the rolling bearing should not exceed 95 degree , and the temperature of the sliding bearing should not exceed 80 degree . Because the temperature is too high, the oil quality will change and destroy the oil film.

General motor operating regulations stipulate that the maximum temperature of rolling bearings does not exceed 95 degrees Celsius, and the maximum temperature of sliding bearings does not exceed 80 degrees Celsius. At the same time, the temperature rise is required not to exceed 55 degrees Celsius (temperature rise is the bearing temperature minus the ambient temperature at the time of testing);

4.4.1 During pump operation, the highest temperature of the bearing shall not exceed 80 degrees.

JB/T5294-91 3.2.9.2 Bearing temperature rise shall not exceed the ambient temperature of 40 degrees, the maximum temperature shall not exceed 80 degrees.

4.3.3 When the pump operates under the specified conditions, the external surface temperature of the built-in bearing shall not be higher than 20 degrees above the temperature of the conveying medium, and the maximum temperature shall not be higher than 80 degrees. The temperature rise of the external surface of the external bearing should not be 40 degrees at the high ambient temperature. The maximum temperature is no higher than 80 degrees.

JB/T7255-94 5.15.3 Service temperature of bearings. Bearing temperature rise shall not exceed the ambient temperature of 35 degrees, the maximum temperature shall not exceed 75 degrees.

JB/T7743-95 7.16.4 Bearing temperature rise shall not exceed the ambient temperature of 40 degrees, the maximum temperature shall not exceed 80 degrees.

4.14 Bearing temperature rise shall not exceed the ambient temperature 35, the maximum temperature shall not exceed 80 degrees.