In the supermarket, the unmanned vending machine is not cooled. We must first power on the sound to make sure that the compressor is running, open the refrigerator door, and the sound heard is a crisp, squeaky sound, indicating that there may be no refrigerant inside, maybe It is a high-pressure leak; how is it humming, then touch the capillary to get the outlet, a little cold, indicating that there is still a little refrigerant, it may be a low-pressure leak.
All of the above are still preliminary shutdown of the unmanned vending machine, specifically combined with the pressure and filter status to determine, after listening to the sound and stop, after 15 to 20 minutes to open the process tube, the ice block to wait for ice to open, When the tube is opened, cut the knife half, take a plastic bag to cover the cutter and the process tube, and then fold it down by hand. Then you can know the pressure inside the system: negative pressure, zero pressure, positive pressure A small amount of refrigerant is still a large amount of refrigerant in positive pressure.
If the unmanned vending machine is a bit cold at the beginning, there will be refrigeration in a few days or even a month, but in the end it will not cool, there is a compressor running sound, it is very stuffy, there is no other sound, you can be sure Ice blocking, in this case, the ice can be cooled again. In the case where the unmanned vending machine determines that the frozen tube is not leaking, it must be refrigerated or temperature-changing. There is a slap in the air, and there is no one in the vending machine. You can see if there is any trace of water flowing through the door of the unmanned vending machine. There is no rust in the door cabinet. If there is a basic can be determined to be a high-pressure leak, then the door tube can be found directly to the door tube, and the door tube can not be found. Most of the door frames are rusted and frozen in the refrigerated outlet pipe. If there is a back, you should also dispose of the drain pipe. Lift a little to the backplate position. The foam must be dug in the water and stick to the leak. The door frame is scraped clean and glued.
Negative pressure, combined with the hum of the front, can be determined to be a high-pressure leak. The positive pressure must be combined with the filter. The zero pressure is more troublesome, and high and low-pressure leaks may occur. The state of the filter can be determined. A large amount of positive pressure has to determine whether the compressor exhaust is normal, generally can not stand with the thumb, judging the compressor is no problem.
No matter whether the unmanned vending machine uses copper pipes, iron pipes, aluminum pipes or composite pipes, it will not leak in the dry environment without water. The unmanned vending machine insulation material is used even better. In the past few years, there is more or less water in the position of the refrigerating pipe. In the refrigerating room, the water in the foam layer is between liquid and solid, and it is used all year round. The water vending machine in the frozen layer foam is frozen. The iron pipe is rusted by water, and the wall of the copper pipe is thin. The water is also rusted. The aluminum tube itself is not easily hydrolyzed, but now the aluminum tube is used to obtain the unmanned vending machine or the capillary tube and the aluminum tube are connected in the refrigerating chamber. The middle part of the capillary tube and the aluminum tube are wrapped together for heat exchange, and the capillary tube has heat. Even if the heat exchange site is in the frozen layer, the water is still in a liquid state. The contact between copper and aluminum in an environment where liquid water is present causes an ionization reaction, causing the aluminum tube to be corroded. Therefore, as long as there is a leak in the refrigerated or recirculated part of the pipeline, there must be water involved. When it leaks to the purple point, when the vacuum is turned on, the moisture will be sucked into the system and left in the filter.
If there is water in the unmanned vending machine filter, it is necessary to open the back pipe or change the pipe. There is no moisture in the zero pressure filter. Generally, the door pipe rust is very serious, the perforation is very large, and only the door pipe or the plug is removed. The condenser is fine.