Motor housing temperature
Thread Content
In one of our company’s 45kW flameproof ExdIICT4 motors (with Class F insulation), the temperature of the casing is around 80°C, while the temperature of the rolling bearings (near the motor end cover) is 75°C. Is it necessary to use an external fan to reduce the temperature? What is the casing temperature limit? What is the temperature of the internal windings at 80°C for the enclosure?
This post was last edited by zdl1966 on 2017-6-17 at 16:53. The surface temperature of the motor ranges from 85 to 90 degrees at most; it cannot go any higher. As it is a high-speed motor, the temperature is generally kept below 80 degrees in summer, and shutdown is necessary if this limit is exceeded (taking into account the insulation grade of the windings). The temperature of the bearings on the side of the motor can reach up to 80 degrees in summer. This depends on the type of grease used in the bearings: if it is lithium-based molybdenum disulfide grease, the temperature can go as high as around 85 degrees; whereas with calcium-based molybdenum disulfide grease, the maximum temperature is around 75 degrees. Because high temperatures can easily cause molybdenum disulfide to become liquid, which is extremely dangerous! A lack of oil in the bearing can lead to serious problems within 10 minutes! AC motors for non-explosion-proof environments on the ground: 4-pole and 6-pole motors. Since their rotation speed is low, it is sufficient to regularly lubricate the bearings and keep the temperature at 70 degrees. If the bearing temperature exceeds 80 degrees (in the case of motors with 4 poles or more), it is definitely due to a lack of lubrication
It should be cooled down; it’s necessary to stop and check it
Generally, it is sufficient to measure the casing temperature. Due to factors such as the motor structure, it is difficult to accurately measure the temperature of the internal windings without specialized probes. A bearing temperature of 75°C is considered the upper limit for operational use. The motor temperature is a bit high, but it depends on the local temperature; in Turpan, Xinjiang, temperatures of 80 degrees aren’t a problem.
The temperature is a bit high; it needs to be disassembled for inspection. The maximum shell temperature is 95 degrees; at 80 degrees, the winding temperature approaches 100 degrees
The temperature is a bit high; it needs to be disassembled for inspection. The maximum shell temperature is 95 degrees; at 80 degrees, the winding temperature approaches 100 degrees
The temperature is a bit high; it needs to be disassembled for inspection. The maximum shell temperature is 95 degrees; at 80 degrees, the winding temperature approaches 100 degrees
The temperature is a bit high; it needs to be disassembled for inspection. The maximum shell temperature is 95 degrees; at 80 degrees, the winding temperature approaches 100 degrees
The housing temperature limit can be found in the manual
The housing temperature limit can be found in the manual