Gree GMV-Pdm450W/NaB-M

DC Inverter Multi
VRF Service Manual
105
5�2 Three Principles of Refrigerant Piping Installation
Observe the three principles of refrigerant piping:
Key Factors Measures to Avoid Failure
Dry
Invasion of outside water
Example: Rainwater, engineering water
Invasion of indoor condensate
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Fabrication of
tting pipe
Vacuuming and
drying
Purge
Clean
Formation of oxides inside
the pipe during welding
Invasion of dust and foreign
articles from outside
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Fabrication of
tting pipe
Purge
Expel with nitrogen 0.05~0.3Mpa
Airtight
Incomplete welding
Leakage from ared port
Leakage from edge
Use suitable materials (copper tube,
soldering bar)
Observe the basic operations for aring of
tting pipe
Observe the basic welding procedures
Observe the basic inerfacting procedures
Airtight test
5�3 Installation of Metal Embedded Pipe
Work Order
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Metal Embedding Diagram Installation of metal Embedded PartsPlotting
Plot the line on ground if possible and use laser to project it onto the roof. This is quick and correct.
Advance Installation of Metal Embedded Parts
Please select according to local codes.
Subsequent Installation of Expansion Bolts
In case that the metal embedded parts cannot be used due to design change, the expansion bolts may be used.
Subsequent Installation of Expansion Bolts
The foot pedal shall be supported on three points if exceeding 2m.
The foot pedal must be xed securely to the ladder.
Please do not work on the top of ladder.
5�4 Installation of Carriage of Refrigerant pipin
5.4.1 Fixing of horizontal pipe
The refrigerant pipe will extend and shrink with each start or stop of the air conditioner unit (5~10 times / hour).
Under a temperature difference of 80
, this extension may reach 13.84mm for every 10m. To prevent failure, the pipes
must be reinforced as follows.
Spacing between supports
Outer diameter of pipe (mm) 6.35-8.52 Over 12.7
Spacing between supports (m) Below 1.2 Below 1.5
Note:
If the gas pipe and liquid pipe are suspended together, the size of liquid pipe shall prevail
CAUTION
Never make the pipe directly contact with the xing metal parts. Thermal insulation shall be provided around the
xing metal parts; otherwise, condensing will occur.