Many thought that the central air conditioner was simply “leaving old oil with new oil”。
But in the eyes of those who really know how to do it, this step is like a “heart-to-heart bridge” for compressors: if it's not working properly, the efficiency drops and the weight goes directly to the end of the day. After 2025, this seemingly ignominious maintenance exercise is becoming a watershed in the industry — technology, environmental standards, precision density, all reshuffled。
For a large central air conditioner, lubricants are systematic blood。
Different refrigerants, different compressors, and corresponding oils all resemble custom formulations。
The screwr requires a slightly more viscous 68, while the centrifuge prefers a lighter 32; the traditional r22 system also uses mineral oil, and a new generation of environmentally friendly refrigerants, such as r134a and r410a, must use poe synthetic oil。
If the oil is mixed in the wrong way, it would be tantamount to filling the gasoline car with diesel fuel, the consequences are understandable。
Over the past two years, environmental regulations have accelerated, new hfo-type low-gwp refrigerants are in full swing, and the associated oils have been replaced, and the pag series has gradually taken place。
The equipment that is still running with old oil, like the veterans wearing broken combat boots, could be accidental for two steps。
The oil selection was right, and the clean-up was the real test。
Many of the protection sites appear to be clean, although more than 30% of the oil and impurities remain in the pipeline。
As a result, the professional team used nitrogen to wash it repeatedly after the oil was released — forcing out the mud and the iron crumbs hidden in the corner of the pipe。
The wettest areas, even using the “vacuum damage + double-blowing” step, remove air and water together and leave a completely clean oil trail。
The moment of true refuelling is about “silence”。
Refrigerated oils are easily combined with water in the air, and even a few minutes of exposure can generate acids and corrosive wires。
So now the oil is replaced almost entirely by negative pressure inhalation — first to create a vacuum below 100 pa and then to “suck in”。
It should also be noted in detail that the weight error control of the electronic scales is within 1 per cent, and that the simultaneous detection of refrigerant leakages, particularly in combustible refrigerant systems, at the time of betting, is subject to every safety rule。
The oil has to be replaced with a "consolidated whole."。
Oil filtration cores and dry filters must be replaced, and the age of the seals cannot be saved。
The screwrs will pay particular attention to the replacement of elements of the oil separators to prevent the mist from being brought into the cooling circuit, and the long heat exchanger surface will be adhesived into a layer of glue and energy efficiency will be brought down directly。
Centrifugal machines focus on the balance of gear case coding, with a slight wear and tear that can reduce efficiency by a few percentage points。
The debug phase, a real test of experience。
The oil pressure difference, the running sound, the vibration frequency is closely observed from the second it starts。
Experienced masters do not rely on instrumentation, and can be judged by hearing alone — oil is not going well, there is a blockage。
The new standards also require a time-delayed test of the oil pressure margin controller to ensure that the warning logic is accurate and that the iplv verification is based on the energy efficiency curve, and that the oil exchange is not only for lubrication but also for energy conservation and stability。
This package, which appears cumbersome, relates to the “lifebook” of each device。
For enterprises, this is not only an expenditure on protection costs, but an investment that avoids large losses and losses。
Over the past few years, the trend towards high-end protection has become more pronounced: spectral oil analysis has become a routine exercise, with a six-monthly forecast of axle bearing wear and tear; enterprise asset management systems have also begun to incorporate energy efficiency and lubrication health data, and oil replacement has been upgraded for the first time from “maintenance” to “strategic maintenance”。
Central air conditioners are afraid of being treated with rough hands。
A mature protection team, like a doctor who listens to a machine's heartbeat, knows when to change blood, how to change it, how to get this heart back to the best rhythm。
A sophisticated standardized process is not just a process requirement, but a responsible attitude to the life of the equipment。
Perhaps this is the core competitiveness of the entire refrigeration sector in the coming years: who knows better about “breathing” of equipment and who can have a stable and efficient initiative。
