Huawei NetCol5000-A025 User Manual page 112

NetCol5000-A025 In-row Air Cooled Smart Cooling
Product
User Manual (300 mm Width)
Figure 4-2 Vacuumizing a unit with a low-temperature component
(1) Pressure gauge 1
(4) Discharge pipe needle
valve
Step 2 In the beginning, the vacuum pump makes loud noises 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 in the cooling system.
Step 3 After 20 minutes, the pressure gauge pointers should be in the negative area and
the vacuum pump makes small noises. Close and open the pressure gauges
repeatedly for several times. The position of the pressure gauge pointers and the
sound made by the vacuum pump should not change. Otherwise, the cooling
system may not be sealed properly.
Step 4 After making sure that the cooling system does not leak, vacuumize for at least 80
minutes. The final pressure of the vacuum pump (absolute pressure) should not
be higher than 60 Pa and the sight glass shows that the vacuum pump is dry
(green) inside.
Step 5 After vacuumizing, close all valves of the pressure gauges and the vacuum pump
(no disconnection is required), preserve the pressure for 10 minutes, and ensure
that the system pressure (absolute pressure) is less than or equal to 90 Pa.
Issue 15 (2020-12-10)
(2) Pressure gauge 2
(5) Liquid pipe needle valve
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4 Power-On Commissioning
(3) Vacuum pump
(6) Low-pressure needle valve
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