Why are intermittent motors more likely to have problems?

If the motor is in an intermittent operating condition with frequent starting, frequent starting will cause the motor to have a serious impact on the winding due to the large current during the starting process, and the winding will overheat and age the insulation, and the reliability of the motor will deteriorate. Especially for motors that are directly started at power frequency, the problem is more serious, so the insulation level of this type of motor should be relatively high, generally not lower than Class F.

For operating conditions with relatively short running time and long downtime, the motor may have condensation, that is, after the motor winding is reduced from the high temperature during operation, the winding will be damp due to temperature difference and protection and surrounding environmental factors. If the motor is started directly under this situation, it may cause the motor winding to be broken down due to poor insulation performance, especially for high-voltage motors, the problem may be more serious. For this reason, moisture-proof heating devices have become standard for high-voltage motors, and motor users should carry out necessary moisture removal before starting the motor.

For high-voltage motors and high-power motors, due to the special characteristics of the motor body and rotor being heavy, rotation protection should be performed regularly during the placement of the motor to prevent adverse effects on the bearing system, that is, deformation of the bearing system components due to the deadweight of the rotor; this problem does not exist for continuously rotating motors, as long as the bearing operating status is closely monitored and relevant maintenance is performed.