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Vacuum test dehydration procedure of refrigerant system. |
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Vacuum test dehydration procedure of refrigerant system. |
| After extract N2 gas for pressure/leak test, vacuum test to be carried out for leakage detection and | |
| drying of system with vacuum pump. If ambient temperature is below 5°C, system to be heated to prevent | |
| water freezing in the system. Especially, the place where moisture can remain in the system is to be | |
| heated partially. | |
| Keep ambient temperature above 16°C as far as possible to speed up the evaporation of moisture. | |
| "CAUTION" Do not attempt dehydration if ambient temperature is below 5°C | |
| Moisture may freeze in the system. | |
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1. |
Vacuum pump to be connected to liquid charging valve with connector. |
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2. |
Vacuum indicator to be installed between the charging valve and the suction valve of the |
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vacuum pump. |
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3. |
Lubricating oil of the vacuum pump to be fresh and clean. And to be confirmed suitable |
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quantity of oil before start-up. |
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4. |
Vacuum dehydration to be carried out after oil charging in crank-case of the compressor |
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so as to dehydrate Iubricationg oil. |
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5. |
Open compressor stop valve and all stop valve in the system. |
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Close all valves and connections to atmosphere. |
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Be sure to open expansion valve, solenoid valve, pressure regulating valve and all valves which |
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are connected to the high and low sides of system and allow the pump to draw a vacuum on |
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entire system. |
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6. |
Open shut-off valve in pump suction line, start vacuum and open charging valve and suction side |
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stop valve of compressor. |
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7. |
Vacuum pump to be operated until the vacuum indicator indicates high vacuum so that the |
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moisture contained in lubricating oil in the refrigerating system can be sufficiently evaporated an |
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extracted |
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8. |
Continue dehydrating until a vacuum of 50 mm hg absolute pressure in reached on vacuum |
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indicator. |
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9. |
When dehydration is completed, hold vacuum for minimum twelve(12) hours and observe vacuum |
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indicator reading continuously and ascertain that the pressure rising rate in the system in 1mm Hg |
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per one hour or less. |
| 10. | If system holds vacuum, disconnect indicator and connect a refrigerant, R-134a bottle to charging |
| connection. The system is now ready for charging and operation. |
