Haier DW-86L486, Руководство по послепродажному обслуживанию

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-------Internal training document for Haier service provider. External disclosure is prohibited --- Classification
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8.5 Refrigerant Charging Process:
8.5.1 Preparation
1) Refrigerant (R134A, R404A, R290, R508b and R170.)
2) Hansen valve
3) Standard electronic scale (error
≤±2g)
4) Vacuum pump (
≥4L)
5) Pressure gauge (high and low pressures shall be read at the same time) See Fig. 1.
8.5.2 System Cutoff
1) Cut off the failure system from the end of the process pipe with a pipe wrench and discharge the
refrigerant in the system.
2) Finish welding the open pipeline with the pressure gauge in 20min. after the system is cut off.
[Notes]
* This series is a two-stage refrigerant system with separated high temperature stage and low
temperature stage. Do not open the two systems at the same time during maintenance and make clear
which system needs to be cut off.
*If the humidity in the maintenance workshop or if it is rainy or cloudy, it is forbidden to cut off the system
and each pipeline of the system which has been cut off shall be welded well at once.
*Since the machine has the strict requirement for moisture in the system, each pipeline port shall be
sealed up with adhesive tape immediately after it is cut off, so as to prevent from air entering the system,
and also the pipeline at each port shall be welded completely in 20min.
8.5.3 Vacuum-pumping
1) Connect the vacuum pump adapter with the public adapter in the middle of the pressure gauge. See
Fig. 2.
2) Switch on the vacuum pump for vacuum-pumping and the vacuum shall be
≤3Pa. See the attached
notes for the reference. See Fig. 3.
3) When the vacuum meets the said requirement, stop pumping at high temperature firstly and quickly
weld and seal up the high temperature charging pipe (the pipe cannot be sealed up when the refrigerant
pressure is too high and the freezer refrigerates), and then continue vacuum-pumping for 1h at the low
pressure. See Fig. 4.
4) After that, switch off the pressure gauge valve. Meanwhile, the machine shall be kept at the negative
pressure for 1h, so as to check if the machine system is under the vacuum state. At the same time,
observe if the pressure indicated by the pressure gauge goes up. Otherwise, vacuum-pumping for 1h
shall be conducted again. Then, continue to keep the machine under the negative state for 1h above
continuously, and stop vacuum-pumping and start charging until the pressure does not go up.