Hitachi UTOPIA R32 Series - 9.2 Triple Evacuation Method

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PMEN0654 rev.0 - 12/2023
9
TRIPLE EVACUATION METHOD
VACUUM PUMPING
9.2 Triple Evacuaon Method
According to the following [Step 1] [Step 2] [Step 3] in order, conduct vacuum drying work.
Step 1
1 Vacuum unl the pressure reaches 2000 microns (2.0 mmHg).
2 Pressurize with nitrogen up to 0.3 MPaG (50 PSIG) for 15 minutes.
3 Release pressure unl reaching the atmosphere level, as low as 0.03 MPaG (5 PSIG).
Step 2
1 Vacuum unl the pressure reaches 1000 microns (1.0 mmHg).
2 Pressurize with nitrogen up to 0.3 MPaG (50 PSIG) for 15 minutes.
3 Release pressure unl reaching the atmosphere level, as low as 0.03 MPaG (5 PSIG).
Step 3
1 Vacuum unl the pressure reaches 500 microns (0.5 mmHg).
2 Stop vacuum pump.
3 Check that the vacuum 500 microns (0.5 mmHG) can maintain for one hour.
 NOTE
• If tool or measuring instruments come into contact with the refrigerant, use the tools or the
measuring instruments exclusively designed for the task at hand.
• Do not perform vacuuming pumping work with valves of the outdoor units open. Otherwise, the
refrigerant charged before shipment may leak and it may result in failure. If moisture remains
inside the pipes, the compressor may be damaged.