Haier 1U71S2SG1FA Service Manual page 177

Refrigerant Charging Procedures
The following requirements are added as the supplementation of conventional procedures:
• During the use of refrigerant charging tools, cross contamination of different refrigerants shall be avoided. The
total length (including the refrigerant pipelines) shall be shortened as much as possible, to reduce the residual of
refrigerant inside;
• The cylinders of refrigerant shall be kept upright;
• Before refrigerant charging, the refrigeration system shall be earthed;
• A label must be pasted on the refrigeration system after refrigerant charging;
• Excessive charging is not allowed; the refrigerant shall be charged slowly;
• In case system leakage is identified, refrigerant charging is not allowed unless the leak point is repaired;
• During refrigerant charging, the charging amount shall be measured with an electronic scale or a spring scale.
The connecting hose between the refrigerant cylinder and the charging equipment shall be relaxed appropriately,
to avoid impact on the measuring accuracy due to stress.
Requirements on storage site of refrigerant
• The cylinder of refrigerant shall be placed in a -10-50 environment with favorable ventilation, and warning labels
°C
shall be pasted;
• The maintenance tool in contact with the refrigerant shall be stored and used separately, and the maintenance
tool of different refrigerants cannot be mixed.
Scrapping and Recovery
Scrapping
Before scrapping, the technician shall be completely familiar with the equipment and all its features. The safe
recovery of refrigerant is recommended. In case the refrigerant recovered needs to be reused, before which the
sample of refrigerant and oil shall be analyzed.
(1) The equipment and operation shall be well known;
(2) Power supply shall be switched off;
(3) The followings shall be guaranteed before scrapping:
• The mechanical equipment shall be convenient for operation on the cylinder of refrigerant (if necessary);
• All personal protective equipment is available and being used correctly;
• The whole course of recovery shall be guided by qualified personnel;
• The recovery equipment and cylinders shall be in line with corresponding standards.
(4) The refrigeration system shall be vacuumized if possible;
(5) In case the vacuum state cannot be reached, vacuumizing shall be carried out from numerous
positions, to pump the refrigerant in each part of the system out;
(6) It shall be guaranteed that the capacity of cylinders is sufficient before recovery;
(7) The recovery equipment shall be started and operated as per the operation instructions of the manufacturer;
(8) The cylinder cannot be charged too full. (The refrigerant charged cannot exceed Uu% of the capacity of
cylinders)
(9) The maximum operating pressure of cylinders cannot be surpassed even only lasting for a short term;
(10) After refrigerant recovery is completed, the cylinder and equipment must be evacuated rapidly, and all the stop
valves on the equipment must be closed;
(11) Before purification and tests, the refrigerant recovered cannot be charged into another refrigeration system.
Note:
The air conditioner shall be marked (with dates and signature) after being scrapped and the refrigerant is
discharged. It shall be guaranteed that the sign on the air conditioner can reflect the flammable refrigerant
charged inside.
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