NetCol5000-A020 Air Cooled In-row Precision Air
Conditioner
User Manual
4 Power-On Commissioning
Issue 01 (2014-06-30)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
63
4.2.3 Vacuumizing
Procedure
Step 1
Connect pressure gauges to the high-pressure needle valve, low-pressure needle valve, and
vacuum pump, as shown in
Figure 4-2
, and start vacuumizing from the two positions.
Figure 4-2
Vacuumizing
(1) Low-pressure needle valve
(2) High-pressure needle valve
(3) Pressure gauge
(4) Nut
(5) Vacuum pump
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 noise. Close and open the pressure gauges alternatively for several times.
The position of the pressure gauge pointers and the sound made by the vacuum pump do not
change. Otherwise, the cooling system may not be sealed properly.