LNEYA ultra-low temperature freezer indoor and outdoor connection has been completed, observe the oil pump oil mark indication to see if there is enough oil, and then start the vacuum pump to see if it is normal. Then unscrew the large valve back cover nut and the fluorine injection nozzle nut, connect the pressure gauge low pressure, connect one end of the thimble to the refrigerant nozzle side, open the low pressure meter switch, vacuum, and quickly show that the vacuum is completed. It may be the vacuum of the yellow tube that the gauge is not open.
The specific time for vacuuming in the ultra-low temperature freezer is about 20-30min. When the pressure gauge pointer is ≤-0.1MPa, then close the pressure gauge low pressure valve, then close the vacuum pump, hold the pressure, observe the pressure gauge pointer for 5 minutes, and see if the pointer rotates. If the system pressure leak is greater than -0.08Mpa, the system has a leak.
If the LNEYA ultra-low temperature freezer compartment leaks, it is necessary to check the possible leak points and repeat the above-mentioned operation vacuuming process, open the small valve and remove the meter. Special attention: After confirming that there is no leakage point, open the small valve spool a little. When the pressure (low pressure) reaches 0.05MPa, close the small valve and quickly remove the pressure gauge (very critical point). Note: This step is to make the system become positive pressure, avoiding the air entering again during the unloading process, and the vacuum is invalid.
Special attention should be paid when opening the LNEYA ultra-low temperature freezer line: first open the small valve completely, and then tighten the valve back nut immediately after opening the large valve completely. Need to pay attention: Be sure to open the valve plug completely, so as not to affect the performance of the ultra-low temperature freezer in the later stage.
Of course, after vacuuming, pay attention to leak detection. Specifically, check each interface and shut-off valve of the internal and external machines first, and apply soapy water to the suspicious points with a sponge block. Each stay should be no less than 3 minutes. If bubbles are formed, There is a leak. At the same time, note that the soapy water should not be too thin, otherwise it will affect the inspection. In summer, the leak should be detected in the stop state, and in the winter, the leak should be detected during the heating operation.
After the vacuum of the ultra-low temperature freezer refrigeration system, users are advised to pay attention to the leakage of the system to avoid the presence of leaks.