4. Installing the refrigerant piping
4.1. Precautions
For devices that use R410A refrigerant
• Use ester oil, ether oil, alkylbenzene oil (small amount) as the refrigeration
oil applied to the flared sections.
• Use C10 copper phosphorus, for copper and copper alloy seamless pipes,
to connect the refrigerant pipes. Use refrigerant pipes with the thicknesses
specified in the table to the below. Make sure the insides of the pipes are clean
and do not contain any harmful contaminants such as sulfuric compounds,
oxidants, debris, or dust.
Warning:
When installing or relocating, or servicing the air conditioner, use only the
specified refrigerant (R410A) to charge the refrigerant lines. Do not mix it with
any other refrigerant and do not allow air to remain in the lines.
If air is mixed with the refrigerant, then it can be the cause of abnormal high pres
-
sure in the refrigerant line, and may result in an explosion and other hazards.
The use of any refrigerant other than that specified for the system will cause
mechanical failure or system malfunction or unit breakdown. In the worst case,
this could lead to a serious impediment to securing product safety.
• Do not use pipes thinner than those specified above.
A
Die
B
Copper pipe
Fig. 4-2
4.2. Indoor unit (Fig. 4-1)
• When commercially available copper pipes are used, wrap liquid and gas pipes
with commercially available insulation materials (heat-resistant to 100 °C or more,
thickness of 12 mm or more).
• The indoor parts of the drain pipe should be wrapped with polyethylene foam insula-
tion materials (specific gravity of 0.03, thickness of 9 mm or more).
• Apply thin layer of refrigerant oil to pipe and joint seating surface before tightening
flare nut.
• Use two wrenches to tighten piping connections.
• Use leak detector or soapy water to check for gas leaks after connections are
completed.
• Use refrigerant piping insulation provided to insulate indoor unit connections. Insulate
carefully following shown below.
• Use correct flare nuts meeting the pipe size of the outdoor unit.
Apply refrigerating machine oil over the entire flare seat surface.
Be sure to only use the flare nuts
that came with the unit.
Fig. 4-1
RP71-140
Liquid pipe
ø9.52 thickness 0.8 mm
Gas pipe
ø15.88 thickness 1.0 mm
B
Flare nut tightening torque
Copper pipe O.D.
(mm)
Flare nut O.D.
(mm)
Tightening torque
(N·m)
ø6.35
17
14 - 18
ø6.35
22
34 - 42
ø9.52
22
34 - 42
ø12.7
26
49 - 61
ø12.7
29
68 - 82
ø15.88
29
68 - 82
ø15.88
36
100 - 120
ø19.05
36
100 - 120
Copper pipe O.D.
(mm)
B (mm)
Flare tool for R410A
Clutch type
ø6.35 (1/4”)
1.0 - 1.5
ø9.52 (3/8”)
1.0 - 1.5
ø12.7 (1/2”)
1.0 - 1.5
ø15.88 (5/8”)
1.0 - 1.5
ø19.05 (3/4”)
1.0 - 1.5
A
Flare cutting dimensions
Copper pipe O.D.
(mm)
Flare dimensions
øA dimensions (mm)
ø6.35
8.7 - 9.1
ø9.52
12.8 - 13.2
ø12.7
16.2 - 16.6
ø15.88
19.3 - 19.7
ø19.05
23.6 - 24.0
R0.4 ~ R0.8
90° ± 0.5°
45° ± 2°
ø
A
RG79D318H02.indd 5
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