Gree GMVVQ224WM/C-X Owner's Manual page 39

GMV Heat Recovery DC Inverter VRF
Step
Step 4
3.6 Vacuum and Drying of Refrigeration System
3.6.1 Air Tightness Test
(1) Notices
1) The range of test pressure gauge for R410A system should be above 4.5MPa.
2) Record the pressure gauge readings, ambient temperature and test time.
3) Pressure correction: The temperature changes by 1℃, and the pressure changes by 0.01
MPa.
4) The pressure should remain unchanged to be qualified.
5) If it is necessary to maintain pressure for a long time, the pressure should be reduced to
0.5 MPa or less. Long periods of high pressure can cause leakage at the weld site and
there is safety hazard.
6) Before the air tightness test for the refrigerant pipe is completed, it is not allowed to conduct
the insulation and wrapping work for any joints between the welding point and the bell
mouth of indoor unit. Please increase pressure from the outdoor side pipes at the same
time. It is forbidden to increase pressure from one side pipe:
NOTE: All welding points can't be heat-insulated and wrapped until the air tightness test is
completed.
(2) Operation procedures for the air tightness test
Photo
Fig.3.6.1
35
Operation instruction
(1) Pull the canvas
casing
(2) upside down and
press it on the butt
flange of the steel
pipe ventilation pipe
with steel bars;
(3) Drill holes with the
manual drill and fix
them with self-
tapping screws;
(4) Seal the two butt
joints with tinfoil
panel and check the
reliability of the
connection.
Note
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