Installing The Refrigerant Piping - Mitsubishi Electric Mr.SLIM PCA-M KA Serie Installationshandbuch

4. Installing the refrigerant piping

A 45 2 B
Fig. 4-1
A Flare cutting dimensions
Copper pipe O.D. Flare dimensions
(mm) øA dimensions (mm)
ø6.35
ø9.52
ø12.7
ø15.88
E
F
Fig. 4-2
Copper pipe O.D.
Flare tool for R32/R410A
(mm)
ø6.35 (1/4")
ø9.52 (3/8")
ø12.7 (1/2")
ø15.88 (5/8")
C
DE
G
Fig. 4-3
C
8.7 - 9.1
12.8 - 13.2
16.2 - 16.6
19.3 - 19.7
B
E Die
F Copper pipe
B (mm)
Clutch type
0 - 0.5
0 - 0.5
0 - 0.5
0 - 0.5
D
E
F
4.1. Precautions
For devices that use R32/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,
D
oxidants, debris, or dust.
Warning:
When installing or relocating, or servicing the air conditioner, use only the
specified refrigerant written on outdoor unit 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
pressure 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.
Liquid pipe
Gas pipe
• Do not use pipes thinner than those specified 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 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 2 wrenches to tighten piping connections.
• Use refrigerant piping insulation provided to insulate indoor unit connections. Insulate
carefully.
• After connecting the refrigerant piping to the indoor unit, be sure to test the pipe
connections for gas leakage with nitrogen gas. (Check that there is no refrigerant
leakage from the refrigerant piping to the indoor unit.)
• Use flared nut installed to this indoor unit.
• In case of reconnecting the refrigerant pipes after detaching, make the flared part
of pipe re-fabricated.
B Flare nut tightening torque
Copper pipe O.D.
(mm)
ø6.35
ø6.35
ø9.52
ø12.7
ø12.7
ø15.88
C Apply refrigerating machine oil over the entire flare seat surface.
Do not apply refrigerating machine oil to the screw portions.
(This will make the flare nuts more apt to loosen.)
D Use correct flare nuts meeting the pipe size of the outdoor unit.
Available pipe size
Liquid side
Gas side
Ο : Factory flare nut attachment to the heat exchanger.
4.3. Indoor unit (Fig. 4-3)
A
Installing procedures
1. Slide the supplied pipe cover 2 over the gas tubing until it is pressed against the
B
sheet metal inside the unit.
2. Slide the provided pipe cover 3 over the liquid tubing until it is pressed against
the sheet metal inside the unit.
3. Tighten the pipe covers 2 and 3 at the both ends (20 mm) with the supplied
bands 4.
A Gas tubing
C
B Liquid tubing
C Band 4
D Pipe cover 2
4.4. For twin/triple combination
Refer to the outdoor unit installation manual.
M35, 50
ø6.35 thickness 0.8 mm ø9.52 thickness 0.8 mm
ø12.7 thickness 0.8 mm ø15.88 thickness 1.0 mm
Flare nut O.D.
(mm)
17
22
22
26
29
29
M35, 50 M60
ø6.35 Ο ø6.35
— ø9.52 Ο
ø12.7 Ο ø15.88 Ο
E Pipe cover 3
F Press the pipe cover against the sheet metal.
G Refrigerant tubing heat insulating material
M60-140
en
Tightening torque
(N·m)
14-18
34-42
34-42
49-61
68-82
68-82
M71-140
—
ø9.52 Ο
ø15.88 Ο
5