Air compressor coil burnout is a complex problem that can be caused by a variety of factors. Here are some of the main reasons and their solutions:

1.Abnormal load and stalled rotation: The air compressor motor is subjected to the load of compressed gas and overcoming mechanical friction during operation. If the pressure ratio or differential pressure is too large, or if the lubrication fails, the load on the motor will increase, resulting in an increase in frictional resistance, causing abnormal loads and stalling. The current at stalled rotor can be 4-8 times the normal operating current, causing the windings to heat up quickly and be damaged. To avoid this, ensure that the compressor is operating under suitable operating conditions, and check and replace the lubricating oil regularly.

2.Short circuits in windings caused by metal shavings: Metal shavings that can be included in the windings are the main cause of short circuits and reduced ground insulation values. These metal shavings can come from copper pipe chips from the construction process, welding slag, or debris that falls from internal wear and component damage to compressors. Therefore, it is very important to strengthen the quality control during the construction process, regularly inspect the inside of the compressor, and clean up the metal chips and debris in time.

3.Contactor problem: If the contactor is not properly selected or of poor quality, it may not be able to withstand the high current impact of the compressor starting, stalled rotor and low voltage, and it is easy to have contact jitter, welding and even falling off, resulting in motor damage. The contactor should be selected correctly according to the load, and the contacts and wiring of the contactor should be checked regularly to ensure good contact.

4.Power supply phase loss and voltage abnormality: The power supply voltage change range is too large or the three-phase voltage is unbalanced, which can easily destroy the motor. Make sure that the power supply voltage is stable to avoid excessive voltage fluctuations, and regularly check the power cord and terminal blocks to ensure reliable connections.

5.Poor oil return of refrigeration system: due to poor oil return of refrigeration system, it will cause the compressor to lack oil and cannot transport enough refrigeration oil to each lubrication part, which will aggravate the friction of each lubrication part, cause the piston and crankshaft to be stuck in a short time, cause the current of the compressor motor to rise sharply, and then burn the motor coil. The normal operation of the refrigeration system should be ensured to avoid problems such as liquid return, blockage of shut-off valve, and impassable oil return hole.

In view of these reasons, they should be investigated one by one and corresponding measures should be taken, such as improving operation and circuit linkage, regularly checking and maintaining automatic air pressure switches, reducing frequent starting, and ensuring the effectiveness of motor protection devices to restore the normal operation of air compressors. If the problem is complex or cannot be solved on your own, it is recommended to contact a professional repair service to deal with it.