20
Unit installation
SPLIT RACK AIR CONDITIONER USER MANUAL
UM.ICUBE2.0-SRAC.SG.0822 August 2022 www.eaton.com
2.9 Vacuum and refill frozen oil
Vacuum
After the leakage test with nitrogen, the air in the pipe must be removed. Please use the vacuum pump to
remove the air in the pipe, and do not use the refrigerant method to remove the air in the pipe, otherwise the
non-condensable gas will not be removed completely. This will increase the high pressure of the system and
decrease the refrigeration performance.
Step 1: First open the indoor globe valve, connect the pressure gauge to the indoor unit gas needle valve (i.e. low
pressure end, thicker nozzle) and liquid path needle valve (i.e. high pressure end, thinner nozzle) respectively, and
then connect the vacuum pump.
Step 2: At the beginning of vacuum pumping, the vacuum pump is loud and white smoke is emitting from the
outlet. If there is still white smoke coming out after 10 minutes, it may be due to poor sealing of the refrigeration
system, or excessive residual refrigerant and moisture in the refrigeration system. Then continue continue to
observe for 10 minutes.
Step 3: After 20 minutes, the pointer of the pressure gauge should be in the negative area, and the sound of
the vacuum pump is relatively low. At this time, the vacuum pressure gauge can be closed and opened several
times, and there should be no obvious change in the pointer position of the pressure gauge and the sound of the
vacuum pump before and after closing, otherwise the refrigeration system may be poorly sealed.
Step 4: After confirming that there is no leakage in the refrigeration system, the vacuum time should
not be less than 80 minutes, and the final vacuum pump display pressure should not be greater than
60Pa (absolute pressure).
Step 5: After pumping the vacuum, close all valves of the pressure gauge, close the vacuum pump (there is no
need to remove the connection), hold pressure for 10 minutes, the pressure of the refrigeration system should
not be greater than 90Pa (absolute pressure).
ote:
N
When pumping vacuum, the globe valve of the indoor unit must be opened, and the globe valve of the
outdoor unit must be opened. And then the air should be removed from the air path needle valve and
the liquid path needle valve of the indoor unit, to ensure not only one end is vacuumized (for units with
cryogenic components please refer to the installation instructions for cryogenic components).
Schematic diagram for needle valve of E04SE unit
Liquid line needle valve
Back valve
needle
valveLiquid
Gas line needle valve
Figure 2.18
