Precharging Refrigerant - Huawei NetCol5000-A050 User Manual

NetCol5000-A050 In-row Air Cooled Smart Cooling
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User Manual
Step 2 In the beginning, the vacuum pump makes loud noise and exhausts white smoke
from the exhaust vent. After 10 minutes, if it still exhausts white smoke, observe it
for another 10 minutes because the cooling system may not be sealed properly or
there may be too much refrigerant or water residues in the cooling system.
Step 3 After 20 minutes, the pressure gauge pointer should be in the negative area and
the vacuum pump makes small noise. Close and open the pressure gauge
alternatively for several times. The position of the pressure gauge pointer and the
sound made by the vacuum pump do not obviously change. Otherwise, the
cooling system may not be sealed properly.
Step 4 Vacuumize the cooling system for at least 80 minutes after checking that the
cooling system does not leak. The pressure displayed on the vacuum pump should
be less than or equal to 60 Pa (absolute pressure). When the pressure stops
dropping, pump for another 10 minutes. The indication of sight glass is dry
(green).
Step 5 After vacuumizing is complete, close all valves of the pressure gauge and the
vacuum pump without disconnecting the pump, and preserve the pressure for 10
minutes. Ensure that the pressure of the cooling system does not exceed 90 Pa
(absolute pressure).
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6.1.3 Precharging Refrigerant

Prerequisites
Before charging refrigerant, ensure that air is exhausted from the gas pipe
connecting to the refrigerant cylinder.
Context
● When charging refrigerant, you are advised to use a safety valve to prevent
refrigerant leakage during the removal of a rubber hose, which may cause
frostbite.
● Wear antifreeze gloves when performing refrigerant-related operations.
● Charge refrigerant (R410A) right after checking that the cooling system does
not leak and the vacuum level meets the requirements.
Procedure
Step 1 Remove the vacuum pump from the vacuumizing equipment, and replace the
vacuum pump with a refrigerant cylinder, as shown in
Issue 08 (2021-09-17)
NO TE
If the minimum reading of the pressure gauge is greater than 60 Pa (absolute pressure),
ensure that the pointer stays at the smallest scale of the pressure gauge in vacuumizing
and preserve the pressure for 1 hour. Then check that the pressure does not rise evidently.
CA UTION
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6 Power-On Commissioning
Figure 6-3 or Figure 6-4.
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