Common knowledge about the use of Panasonic air conditioner compressors:
1. The role of the compressor in the system: It sucks in low-pressure refrigerant gas returned from the evaporator, compresses it, and forms high-temperature and high-pressure refrigerant vapor. For the compressor, whether the air conditioner is cooling or heating, the function and operating condition of the compressor does not change much; it's just that the operating conditions have changed slightly, with higher running pressure during heating.
2. The system needs to maintain a good oil return status: The refrigeration oil inside the compressor serves a lubrication function, effectively preventing wear on mechanical parts. Its sealing effect helps maintain the pressure difference between the high and low-pressure sides. Additionally, due to the continuous circulation of the refrigeration oil, it can promptly carry away the heat generated by the friction surfaces.
A portion of the refrigeration oil in the compressor is discharged into the system along with the refrigerant. The discharged oil dissolves in the liquid refrigerant in the condenser; as it enters the evaporator, it gradually separates from the refrigerant, adhering to the pipe walls or becoming misty and returning to the compressor with the gas. However, if the refrigeration oil cannot smoothly return after being discharged from the compressor, it will cause poor lubrication and eventually lead to excessive wear on the friction surfaces.
Therefore, when installing and using the system, the oil return situation must be considered:
① When installing the entire unit, try to minimize the length of the connecting pipes between indoor and outdoor units and the height difference between them. Explain to users that excessively long pipes or large height differences may lead to poor oil return in the system. During installation, an oil return bend should be set up (as noted by Beijing Panasonic Air Conditioner Repair).
② After powering on the compressor, it should run continuously for at least 5 minutes. This ensures the proper oil return state of the compressor. If the running time is too short, a significant amount of refrigeration oil may accumulate in the system and fail to return to the compressor. Over time, this can lead to wear inside the compressor due to insufficient oil. This point also needs to be explained to the user.
3. Under any circumstances, liquid refrigerant must not enter the compressor directly.
⑴ Refrigerant should be injected into the air conditioning system from the rear end of the condenser. Otherwise, liquid refrigerant will directly enter the compressor. Since liquid refrigerant has extremely strong solubility with refrigeration oil, it will dilute the existing oil film between the mechanical parts of the compressor, causing poor lubrication and abnormal wear on the compressor. Liquid refrigerant entering the compressor may also adhere to the terminal block, causing temporary insulation and voltage withstand issues.
⑵ When replenishing the refrigerant in the air conditioning system, be cautious: Do not add excessive refrigerant, otherwise it may exceed the maximum allowable charge of the compressor, leading to direct suction of liquid refrigerant into the compressor. Due to the incompressibility of liquids, this could damage the compressor.
Source: Beijing Panasonic Air Conditioner Repair Phone http://blog.tianya.cn/blogger/blog_main.asp?BlogID=3484683