Common causes and countermeasures of motors
Causes of common motor faults and countermeasures:
First, the motor temperature rises too high or smoke
This type of fault is a manifestation of overheating of the motor. There are many reasons for this: there are external factors of the motor (such as poor power supply quality, excessive load, high ambient temperature and poor ventilation, etc.); there are also reasons for the motor itself.
Common causes and countermeasures for the motor itself:
1. The winding connection is wrong, and the star is connected to a triangle or vice versa.
2. When the stator windings are short-circuited or grounded, the current is increased and the copper loss is increased. If the fault is not serious, only need to re-insulate the insulation, and the winding should be replaced seriously.
3. The one-phase winding of the stator is broken, or one of the parallel windings is broken, causing the three-phase current to be unbalanced and the windings to overheat.
4. Rotor broken bars. Solder or replace the copper strip rotor, and replace the cast aluminum rotor.
5. Fixed and rotor rubbing. It can check whether the bearing is loose, whether the rotor and the rotor are poorly assembled.
6. The ambient temperature is high, the surface of the motor is much dirt, or the air passage is blocked;
7. The motor fan is faulty and the ventilation is poor;
Second, the bearing is overheated
When the temperature of the rolling bearing of the motor exceeds 95 °C and the temperature of the sliding bearing exceeds 80 °C, the bearing is overheated. The reasons and countermeasures are as follows:
1. Bearing damage should be replaced.
2. Rolling bearing grease is too little, too much or there are impurities such as iron filings. The capacity of the grease should not exceed 70% of the bearing and bearing cap volume, and should be replaced with new ones.
3. The bearing and the end cap are too tight or too loose. The bearing housing is machined when it is too tight, and the steel sleeve is placed inside the end cover when it is too loose.
4. The motor ends or bearing caps are poorly assembled. Flatten the end cap or bearing cap stop and tighten the screws.
5. The drive belt is too tight or the coupling is poorly assembled. Adjust the belt tension and correct the coupling.
6. Sliding bearing oil is too little, there are impurities or oil ring stuck, should be refueled, replaced with new oil, repair or replace the oil ring.
7. The bearing clearance is too large or too small;
8. The motor shaft is bent.
Third, the noise is abnormal
1. When the rotor and the rotor are rubbed, a harsh "click" will be produced. Bearings should be inspected and damaged for renewal. If the bearing is not broken, it is found that the bearing can be inserted into the inner ring or the outer ring or the bearing and the end cover can be replaced.
2. The motor is out of phase and the hum is particularly loud. Can be powered off and then closed to see if it can start normally. If it does not start, there may be a phase break. Phase loss operation can also occur if the contacts of the switch and contactor are not turned on.
3. When the bearing is seriously deficient in oil, a "click" sound can be heard from the bearing chamber. The bearings should be cleaned and new oil added.
4. When the wind leaves touch the shell or have debris, it will make a crash. The blades should be calibrated to remove debris from the blades.
5. The rotor bar is broken, and the high and low "beep" sound occurs, the rotation speed is also slow, and the current is increased.
6. The first end of the stator winding is wired incorrectly, with a low hum and low speed.
7. The stator and rotor core are loose;
Fourth, the vibration is too large
1. The rotor of the motor is unbalanced (such as the weight of the screw on the rotor) should be corrected for dynamic balance.
2. The drive pulley is unbalanced and the static balance should be corrected.
3. The shaft is bent. The shaft should be replaced, or the car should be straight (sleeve).
4. The installation foundation is uneven or unstable. Should be reinstalled and fixed.
5. The rotor bar breaks, causing the load current to oscillate when it is large and small.
6. The coupling is not properly assembled or loose.
7. The driven machine loses its dynamic balance.
8. The stator winding has a local fault, and the rotating magnetic field is unbalanced to cause vibration.
9. The bearing clearance is too large due to wear;
10. The core is deformed or loose;
11. The fan is unbalanced;
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Label: Causes and Countermeasures for Common Faults of Motors
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