Installation Of Refrigerant Piping - Gree DC Inverter Multi VRF Service Manual

DC INVERTER MULTI VRF

6.6 Installation of Refrigerant Piping

1 Precautions on piping works
At the site of transport, storage and construction, the two ends of copper pipes shall be sealed
with plastic sealing caps. Before welding, copper pipes must be cleaned (washing the inner side
of pipe with alcohol) to ensure no dust and no water in pipeline.
Nitrogen-filled welding shall be used for the welding of copper pipes. Nitrogen pressure shall be
0.05 0.3MPa. Nitrogen flow can be sensed by hand.
When multiple multi-connected units are installed, refrigerant piping must be marked to avoid
confusion between pipes of different units.
A two-way drier shall be mounted at the liquid pipe side at the place where an outdoor unit is
connected.
2 Assemble copper pipes
The copper pipe shall be vertically inserted to the specified length. The centerline of two
assemblies shall overlap. The position shall be determined for welding. To ensure correct
mounting size, do not determine the position with your hands, thus to prevent the copper pipe
from moving when heated.
See below for the welding size of copper pipe:
If the mounting clearance is too large, the diameter of coarse pipe may be reduced to an
appropriate value to according to applicable specifications.
3 Installation of branch pipe
The branch pipe plays the function to divert the refrigerant flow. Therefore, the selection and
installation of branch pipe is very important to the operation of multi-unit. Based on correct
selection of branch pipe, the branch pipe must be installed according to installation specifications.
Connection schematics for Y-type branch pipe
The connection of Y-type branch pipe is as shown below. The inlet is connected to outdoor unit or
previous branch; the outlet is connected to indoor unit or next branch.
Site pipe
Outdoor Unit
Outer diameter of pipe D
(mm)
6.35
φ
9.52, 12.7
φ φ
15.8
φ
19.05, 22.2, 25.4
φ φ φ
28.6, 31.8
φ φ
≥ 35
φ
Outlet 1
Inlet
Outlet 2
Y-type Manifold
Pipe
INSTALLATION
Min. insert depth B
(mm)
6
7
8
10
12
14
To other manifold
pipe or indoor unit
Site pipe
Clearance A-D
0.05 0.21
0.05 0.27
0.05 0.35
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