Eight major causes of motor burnout in refrigeration compressors

Eight major causes of motor burnout in refrigeration compressors

As the core power source of the air conditioning system, the normal operation of the air conditioning compressor plays a decisive role in the efficiency and lifespan of the entire air conditioning system. However, in practical use, the burning problem of air conditioning compressors is quite common, and the reasons are diverse and complex. The following is a detailed explanation of the eight main causes of air conditioning compressor burnout:

1. Frequent starting of air conditioning compressor: Although a step-down starting circuit design is used, the initial current of the air conditioning compressor will still exceed the rated value by several times, causing the motor temperature to rise rapidly. If the temperature setting of the air conditioner is unreasonable, such as too low refrigeration or too high heating, it will cause the compressor to start and stop frequently, greatly reducing its service life.

2. Unstable power supply voltage: When the quality of the power supply is poor and the voltage is too high or too low, it will have a negative impact on the air conditioning compressor motor. Especially when the operating voltage exceeds the rated range of the compressor, motors that are in an inefficient and overheated state for a long time are prone to a decrease in insulation performance, and the windings may be burned out due to overheating; In addition, three-phase voltage or current imbalance can also increase motor losses (iron and copper losses), causing the compressor motor coil temperature to be too high. Failure of overheat protection may lead to motor insulation burnout, ultimately causing coil short circuit burnout.

3. Insufficient cleanliness of the air conditioning copper pipe system: If the system contains moisture, it will lead to a decrease in the insulation performance of the compression motor. After experiencing high and low temperature cycling changes, water, refrigerant, and refrigeration oil will produce acidic substances, which will corrode the insulation layer of the motor. Under long-term operation, there is a risk of the air conditioning compressor motor being burned out

4. The rotating parts of the air conditioning compressor are stuck: Once the rotating parts are stuck, if the motor protection device fails to operate effectively, the compressor motor may burn out due to overload.

5. Incomplete cleaning of refrigeration system: For air conditioning refrigeration systems that have experienced compressor burnout faults before, it is necessary to thoroughly clean them before replacing with new compressors. If strong acidic substances generated during the burning process of the original compressor remain in the system, these acidic residues will corrode the insulation layer of the new compressor motor after the operation of the new compressor, leading to further burning.

6. Insufficient cooling of the air conditioning compressor: Improper control of overheated return air in the air conditioning system results in high return air temperature or low return air volume, making it impossible for the compressor motor coil to receive effective cooling. This situation is more common in air-cooled heat pump units, and high return air temperature can also lead to high exhaust temperature, causing a series of compressor problems.

7. Manufacturing process defects of air conditioning compressors: If the motor burns out shortly after the air conditioner is used, there may be process quality issues during the compressor manufacturing process.

8. Fault in the starting contactor of the air conditioning compressor: The starting contactor is an important component to ensure the safe and stable start of the air conditioning compressor. When its contact resistance is too high or sintered, it may cause a short circuit of the motor, which can lead to motor burnout; In addition, poor circuit contact may also cause excessive starting current, which can easily ignite and burn out the air conditioning compressor due to the instantaneous strong current impact. Therefore, ensuring the good condition of the starting contactor and its related circuits is crucial for preventing compressor burnout.