Installing The Refrigerant Piping - Mitsubishi Electric PLA-A-BA4 Series Installation Manual

4. Installing the refrigerant piping

45 2
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")
9.52 (3/8") 1.0 - 1.5, 3/64 - 1/16
12.7 (1/2") 1.0 - 1.5, 3/64 - 1/16
1.0 - 1.5, 3/64 - 1/16
15.88 (5/8")
1.0 - 1.5, 3/64 - 1/16
19.05 (3/4")
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
refrigeration oil applied to the flared sections.
• Use C1220 copper phosphorus for copper and copper alloy seamless pipes,
to connect the refrigerant pipes. Use refrigerant pipes with the thicknesses
specified 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 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. Air enclosed in
the lines can cause pressure peaks resulting in a rupture and other hazards.
A12, A18
Liquid pipe ø6.35 mm, ø1/4 inch
thickness 0.8mm, 1/32 inch
Gas pipe ø12.7 mm, ø1/2 inch
thickness 0.8mm, 1/32 inch
• Do not use pipes thinner than those specified above.
4.. 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 (specific 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
tightening flare nut.
• Use two wrenches to tighten piping connections.
• Use refrigerant piping insulation provided to insulate indoor unit connections.
Insulate carefully.
B Flare nut tightening torque
Copper pipe O.D. Flare nut O.D.
(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
ø19.05, 3/4
C Apply refrigerating machine oil over the entire flare seat surface.
D Use correct flare nuts meeting the pipe size of the outdoor unit.
Available pipe size
A12, A18
Liquid side ø6.35
Gas side ø12.7
: Factory flare 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
(mm, inch) (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
36, 1-27/64 100-120, 71-86
36, 1-27/64 100-120, 71-86
A24, A30, A36, A42
ø9.52
ø15.88
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