Manual Diagnosis Method of Motor Fault

The motor is the core part of many devices and systems, and its normal operation is crucial to the stable operation of the entire system. However, various faults may occur during the operation of the motor, such as leakage, open circuit, turn-to-turn short circuit, etc. In order to detect and deal with these faults in time, we need to make judgments through manual visual perception such as seeing, hearing, smelling, and touching.

First, we can judge whether the motor is abnormal by "smelling". For example, when the temperature inside the motor is too high, it may cause the smell of paint to volatilize; if the insulation layer maintenance network is abnormal, there may also be a smell of burning objects.

Secondly, we can judge whether the motor is abnormal by "looking". For example, if the stator winding of the motor is short-circuited, it will generally be accompanied by smoke; overload operation of the motor will cause the speed to drop; if the motor is abnormally operated or stopped, sparks will appear due to ignition, and the fuse may also be blown or the parts may be stuck; the transmission device of the motor is blocked, the motor is unstable, the foot bolts of the motor are loose, etc., which will cause the motor to vibrate violently during operation; if the internal contact points and connections of the motor are abnormal in color or have traces of fire or smoke, then the possible problems are local overheating of the motor, poor contact of the motor conductor, and burning of the motor winding.

Once again, we can judge whether the motor is abnormal by "listening". For example, uneven air gap between the stator and rotor of the motor, unbalanced three-phase current and loose iron core will cause the motor to emit electromagnetic noise with varying heights; if the motor bearing makes abnormal sounds, there may be several situations, namely, the squeaking sound of the bearing due to lack of lubrication, the chirping sound of the ball grease drying up, and the rattling sound or creaking sound of the bearing ball damage; the transmission mechanism and the driven mechanism of the motor will also have abnormal sounds. If it is a uniform snapping sound, it means that there is a bulge in the belt joint. If it is a uniform thumping sound, it means that the coupling or pulley and the shaft are loose and the key or keyway is worn. If it is an uneven collision sound, it may be that the fan blades and the outer cover have collided.

Finally, we can judge whether the motor is abnormal by "touching". It mainly refers to the judgment of the motor temperature. When the following faults occur, the motor will overheat, including poor ventilation, motor overload, motor short circuit, three-phase current imbalance, too frequent starting or braking of the motor, and abnormal bearing temperature of the motor.

In general, through manual visual perception such as seeing, hearing, smelling and touching, we can promptly detect and deal with various faults of the motor to ensure the normal operation of the motor.