When the motor runs or fails, four methods can be used to prevent and troubleshoot in time by seeing, hearing, smelling and touching to ensure the operation of the motor.

I. Look

Observe whether there is any abnormality during the operation of the motor, which is mainly shown in the following cases.

1.When the stator winding is short-circuited, you may see the motor smoke.

2. When the motor is seriously overloaded or running in phase, the speed will be slow and there is a heavy humming sound.

3. When the motor repair network runs normally but stops suddenly, you may see sparks at the loose wiring; fuse is blown or a part is stuck, etc.

4. If the motor vibrates violently, it may be that the transmission device is stuck or the motor is poorly fixed, the foot bolt is loose, etc.

5. If there are discoloration, burn marks and smoke stains at the contact points and connections in the motor, it means that there may be local overheating, poor contact at the conductor connections or burned winding, etc.

2. Listen

When the motor is running normally, it should make a uniform and light humming sound, no noise and special sound. If the noise is too loud, including electromagnetic noise, bearing noise, ventilation noise, mechanical friction sound, etc., it may be a precursor of failure or failure phenomenon.

1. For electromagnetic noise, if the motor makes a high and low and heavy sound, the reasons may be the following.

(1) Uneven air gap between stator and rotor, at this time, the sound is high and low and the time between high and low sound is unchanged, which is caused by bearing wear and tear, thus making the stator and rotor different from the center.

(2) three-phase current imbalance. If the sound is dull, it means that the motor is seriously overloaded or running out of phase.

(3) Loose iron core. In the operation of the motor, the core fixing bolt is loosened due to vibration, which causes the core silicon steel piece to be loose and make noise.

2. For bearing noise, the motor should be monitored frequently during operation. The method of monitoring is: hold one end of the screwdriver against the bearing installation part, and the other end is close to the ear, then you can hear the bearing running sound. If the bearing is running normally, the sound will be continuous and small rustling sound, there will be no high and low change and metal friction sound. If the following sounds occur, it is abnormal.

(1) bearing operation with squeaking sound, which is the sound of metal friction, generally due to bearing oil shortage, should be disassembled bearing to fill the appropriate amount of grease.

(2) If there is a chirping sound, which is the sound of the ball rotation, generally for the grease dry or lack of oil caused, can be filled with the appropriate amount of grease.

(3) If there is a click or creak sound, it is the sound generated by the irregular movement of the ball in the bearing, which is caused by the damage of the ball in the bearing or the motor is not used for a long time and the grease dries up.

3. If the transmission mechanism and the driven mechanism make continuous and non-suddenly high and low sound, it can be divided into the following cases.

(1) Periodic snapping sound, caused by the belt joint is not smooth.

(2) Periodic thud sound, for the coupling or pulley and shaft loosening and key or keyway wear caused by.

(3) Uneven collision sound, caused by the wind blade collision fan cover.

3. Smell

By smelling the smell of the motor, you can also judge and prevent the failure. If a special paint smell is found, it means the internal temperature of the motor is too high; if a heavy paste smell or burnt smell is found, it may be that the insulation layer repair network is pierced or the winding is burnt.

Four, touch

Touching the temperature of some parts of the motor can also determine the cause of failure. In order to ensure the safety, the back of the hand should touch the motor shell and bearing.

1. Poor ventilation. Such as fan off, ventilation channel blockage, etc.

2. Overload. The current is too large and the stator winding is overheated.

3. Stator winding inter-turn short circuit or three-phase current imbalance.

4. Frequent starting or braking.

5. If the temperature around the bearing is too high, it may be caused by bearing damage or lack of oil.