Connecting Pipes; Refrigerant Piping - Mitsubishi Electric PUMY-P112VKM1 Installation Manual

4. Installing the refrigerant piping
45°± 2°
A Flare cutting dimensions
B Flare nut tightening torque
Fig. 4-5
A (Fig. 4-5)
Copper pipe O.D. Flare dimensions
(mm) 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
B (Fig. 4-5)
Copper pipe O.D. Flare nut O.D.
(mm)
ø6.35
ø6.35
ø9.52
ø12.7
ø12.7
ø15.88
ø15.88
Fig. 4-6
D
A Front piping cover
B Piping cover
C Stop valve
D Service panel
E Bend radius : 100 mm - 150 mm
Fig. 4-7
Tightening torque
(mm) (N·m)
17 14 - 18
22 34 - 42
22 34 - 42
26 49 - 61
29 68 - 82
29 68 - 82
36 100 - 120
A
A Die
B Copper pipe
A
4.4. Connecting pipes (Fig. 4-5)
Fig. 4-1 is a sample of piping system.
• Conduct sufficient anti-condensation and insulation work to prevent water dripping
from the refrigerant piping. (liquid pipe/gas pipe)
• Increase insulation depending on the environment where the refrigerant piping is
installed, or condensation may occur on the surface of the insulation material. (In-
sulation material Heat-resistant temperature: 120 °C, Thickness: 15 mm or more)
* When the refrigerant piping is used in locations subject to high temperature and
humidity such as in the attic, further addition of insulation may be required.
• To insulate the refrigerant piping, apply heat-resistant polyethylene foam between
the indoor unit and insulation material as well as to the net between the insulation
material filling all gaps.
(Condensation forming on the piping may result in condensation in the room or
burns when contacting the piping.)
• 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. A
• Use two wrenches to tighten piping connections. B
• Use leak detector or soapy water to check for gas leaks after connections are
completed.
• Apply refrigerating machine oil over the entire flare seat surface. C
• Use the flare nuts for the following pipe size. D
• When bending the pipes, be careful not to break them. Bend radius of 100 mm to
150 mm is sufficient.
• Make sure the pipes do not contact the compressor. Abnormal noise or vibration
may result.
1 Pipes must be connected starting from the indoor unit.
Flare nuts must be tightened with a torque wrench.
2 Flare the liquid pipes and gas pipes and apply a thin layer of refrigeration oil
(Applied on site).
• When usual pipe sealing is used, refer to Table 3 for flaring of R410A refrigerant
pipes.
The size adjustment gauge can be used to confirm A measurements.
Warning:
When installing the unit, securely connect the refrigerant pipes before starting
the compressor.
* To connect the CONNECTION KIT (PAC-LV11M-J), refer to the installation manual
for the CONNECTION KIT.
Table 3 (Fig. 4-6)
Copper pipe O.D. (mm)
ø6.35
ø9.52
ø12.7
ø15.88
ø19.05
4.5. Refrigerant piping (Fig. 4-7)
Remove the service panel D (three screws) and the front piping cover A (two screws)
and rear piping cover B (two screws).
1 Perform refrigerant piping connections for the indoor/outdoor unit when the outdoor
unit's stop valve is completely closed.
2 Vacuum-purge air from the indoor unit and the connection piping.
3 After connecting the refrigerant pipes, check the connected pipes and the indoor
unit for gas leaks. (Refer to 4.6. Refrigerant pipe airtight testing method)
C
4 Vacuumize the refrigerant lines through the service port of the liquid and gas stop
valves. And then open the stop valves completely (for both the liquid and gas stop
B
valves). This will completely connect the refrigerant lines of the indoor and outdoor
units.
• If the stop valves are left closed and the unit is operated, the compressor and
control valves will be damaged.
• Use a leak detector or soapy water to check for gas leaks at the pipe connec-
tion sections of the outdoor unit.
• Do not use the refrigerant from the unit to purge air from the refrigerant
lines.
E
• After the valve work is completed, tighten the valve caps to the correct torque:
20 to 25 N·m (200 to 250 kgf·cm).
Failure to replace and tighten the caps may result in refrigerant leakage. In
addition, do not damage the insides of the valve caps as they act as a seal to
prevent refrigerant leakage.
5 Use sealant to seal the ends of the thermal insulation around the pipe connection
sections to prevent water from entering the thermal insulation.
A (mm)
Flare tool for R410A Flare tool for R22·R407C
Clutch type
0 - 0.5 1.0 - 1.5
0 - 0.5 1.0 - 1.5
0 - 0.5 1.0 - 1.5
0 - 0.5 1.0 - 1.5
0 - 0.5 1.0 - 1.5
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