All motors have a fixed operating power, which is called rated power, and the unit is watt (W). If the actual power of the motor exceeds the rated power of the motor under certain circumstances, this phenomenon is called motor overload. Overload can easily lead to motor overheating, resulting in reduced winding insulation, and ultimately motor burning.
The influence and harm of overload operation on the motor mainly include the following aspects:
1. Long time overload operation of control motor operating elements and link lines will cause heating of contacts of contactors and circuit breakers, reduce their service life, and in serious cases, cause burning of contacts and burning of motor during open phase operation;
2. For variable frequency motors, the power components inside the frequency converter will be in full load and easy to be damaged;
3. For the motor bearing system, the overload operation for a long time will easily lead to overheating of the bearing, failure of the lubricating grease, and shortened service life of the raw materials.
