Installing The Refrigerant Piping - Mitsubishi Electric MR. SLIM PLA-ABA Installation Manual

4. Installing the refrigerant piping

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Flare cutting dimensions
Copper pipe O.D. Flare dimensions
(mm, inch) A dimensions (mm, inch)
6.35, 1/4 8.7 - 9.1, 11/32 - 23/64
9.52, 3/8 12.8 - 13.2, 1/2 - 33/64
12.7, 1/2 16.2 - 16.6, 41/64 - 21/32
15.88, 5/8 19.3 - 19.7, 49/64 - 25/32
19.05, 3/4 23.6 - 24.0, 15/16 - 61/64
B (mm, inch)
Copper pipe O.D.
Flare tool for R410A
mm (inch)
1.0 - 1.5, 3/64 - 1/16
6.35 (1/4")
1.0 - 1.5, 3/64 - 1/16
9.52 (3/8")
12.7 (1/2") 1.0 - 1.5, 3/64 - 1/16
15.88 (5/8") 1.0 - 1.5, 3/64 - 1/16
19.05 (3/4") 1.0 - 1.5, 3/64 - 1/16
Fig. 4-1
B
Die
Copper pipe
Fig. 4-2
Clutch type
4.1. Precautions
For devices that use R410A refrigerant
• Use ester oil, ether oil or alkylbenzene oil (small amount) as the refrigera-
tion oil applied to the fl ared sections.
• Use C1220 copper phosphorus for copper and copper alloy seamless pipes,
to connect the refrigerant pipes. Use refrigerant pipes with the thicknesses
specifi ed in the table 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 moving the air conditioner, use only the specifi ed refriger-
ant (R410A) to charge the refrigerant lines. Do not mix it with any other refrig-
erant and do not allow air to remain in the lines. Air enclosed in the lines can
cause pressure peaks resulting in a rupture and other hazards.
A12, A18
ø6.35 mm, ø1/4 inch
Liquid pipe
thickness 0.8mm, 1/32 inch
ø12.7 mm, ø1/2 inch
Gas pipe
thickness 0.8mm, 1/32 inch
• Do not use pipes thinner than those specifi ed above.
4.2. Connecting pipes (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, 212 °F
or more, thickness of 12 mm, 1/2 inch or more).
• The indoor parts of the drain pipe should be wrapped with polyethylene foam
insulation materials (specifi c gravity of 0.03, thickness of 9 mm, 23/64 inch or
more).
• Apply thin layer of refrigerant oil to pipe and joint seating surface before tighten-
ing fl are nut.
• Use two wrenches to tighten piping connections.
• Use refrigerant piping insulation provided to insulate indoor unit connections. In-
sulate carefully.
Flare nut tightening torque
Copper pipe O.D. Flare nut O.D.
(mm, inch) (mm, inch)
ø6.35, 1/4
ø6.35, 1/4
ø9.52, 3/8
ø12.7, 1/2
ø12.7, 1/2
ø15.88, 5/8
ø15.88, 5/8 36, 1-27/64
ø19.05, 3/4 36, 1-27/64
Apply refrigerating machine oil over the entire fl are seat surface.
Use correct fl are nuts meeting the pipe size of the outdoor unit.
Available pipe size
A12, A18
Liquid side ø6.35
Gas side ø12.7
: Factory fl are nut attachment to the heat exchanger.
A24, A30, A36, A42
ø9.52 mm, ø3/8 inch
thickness 0.8mm, 1/32 inch
ø15.88 mm, ø5/8 inch
thickness 1.0mm, 3/64 inch
Tightening torque
(N-m, ftlbs)
17, 43/64 14-18, 10-13
22, 7/8 34-42, 25-30
22, 7/8 34-42, 25-30
26, 1-3/64 49-61, 35-44
29, 1-9/64 68-82, 49-59
29, 1-9/64 68-82, 49-59
100-120, 71-86
100-120, 71-86
A24, A30, A36, A42
ø9.52
ø15.88
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