1. The equipment operates at overload, causing the motor to run at rated current or beyond rated current for a long time. Special attention should be paid to the fact that the starting current of the motor is 3-5 times the rated current, so it is advisable to avoid starting the equipment with or at full load (mainly depending on the matching margin between the rated current and normal operating current of the motor).
2. The motor operates in a relatively humid working environment. Before starting the motor, the insulation of the coil to ground and between phases should be checked.
3. The mechanical failure of the pump caused the motor to overload, resulting in excessive current and burning of the coil.
4. The heat dissipation problem of the motor. Generally, motor coils use air-cooled casings, while submersible pumps use water-cooled casings. Large motors often use air-to-air heat exchangers and air-water heat exchangers for cooling. If the cooling water (air) is cut off, causing the coil to be unable to dissipate heat, it may burn out the coil.
1. The motor shaft is not concentric, it is recommended to replace the motor shaft;
2. The motor shaft is worn, it is recommended to replace the motor shaft;
3. The motor bearing box and bearings are loose, it is recommended to replace them at the same time;
4. The concentricity between the water pump and the motor is not good, it is recommended to adjust it;
5. The motor temperature is too high and the lubricating oil used for the bearings is not good. It is recommended to use high-temperature resistant lubricating oil or check the cause of the high temperature in the motor.