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.
64
Step 4
Check that the time for vacuumizing is 80 minutes or longer after making sure that the
cooling system does not leak, the pressure displayed on the vacuum pump is less than or equal
to 60 Pa (absolute pressure), and the sight glass is dry (green).
Step 5
After vacuumizing, close valves of all pressure gauges, the vacuum pump (no disconnection is
required), remain the pressure for 10 minutes, and ensure that the system pressure is equal to
or smaller than 90 Pa (absolute pressure).
If the pressure gauge precision does not reach 60 Pa (absolute pressure), ensure that the pressure gauge
pointers stay in the minimum scale. In addition, remain the pressure for one hour and check whether the
pressure increases obviously.
----End
4.2.4 Partially Charging in Refrigerant
Prerequisites
Before refrigerant charging, ensure that the air is exhausted from the hose connecting to the
steel vessel of the refrigerant.
Context
Wear protective gloves when handling refrigerant.
Charge the refrigerant (R410A) after checking that the cooling system does not leak and
the vacuum meets the requirements.
Charge refrigerant as required upon calculation shown in
4.2.1 Calculation Requirements
of Chilled Oil and Refrigerant to Be Charged
.
Charge refrigerant to the three needle valves shown in
Figure 4-2
simultaneously.
Procedure
Step 1
Replace the vacuum pump with the steel vessel of the refrigerant.
Step 2
Slightly release the valve of the steel vessel and the hose nut in
Figure 4-2
until you feel cold
air at the nut. Fasten the nut and the steel vessel valve.
Step 3
Put the steel vessel on an electronic balance and clear the reading.
Step 4
Open valves of the pressure gauges and the steel vessel in
Figure 4-2
and start charging
refrigerant.
