Mitsubishi Electric PU-FRP71VHA2 Installationshandbuch Seite 6

4. Installing the refrigerant piping
A
A Flare cutting dimensions
B Flare nut tightening torque
A (Fig. 4-1)
Copper pipe O.D.
(mm)
ø6.35
ø9.52
ø12.7
ø15.88
en
ø19.05
B (Fig. 4-1)
Copper pipe O.D.
(mm)
ø6.35
ø6.35
ø9.52
ø12.7
ø12.7
ø15.88
ø19.05
A
D
A
B
C D
5
B
C
Fig. 4-1
D
Flare dimensions
øA dimensions (mm)
8.7 - 9.1
12.8 - 13.2
16.2 - 16.6
19.3 - 19.7
23.6 - 24.0
Flare nut O.D. Tightening torque
(mm) (N·m)
7 14 - 18
22 34 - 42
22 34 - 42
26 49 - 61
29 68 - 82
29 68 - 82
6 100 - 120
A
A Die
B Copper pipe
B
Fig. 4-2
A Front piping cover
C B Piping cover
C Stop valve
D Service panel
E Bend radius : 100mm - 150mm
B
A
E
A WIRING WORK: Connect to power and
indoor unit
B WIRING WORK: Connect to cylinder unit or
hydrobox
C PIPING WORK: Connect to cylinder unit or
hydrobox
D PIPING WORK: Connect to indoor unit
This tap mark indicates the cylinder/hydro
unit connection side for the following parts.
• Terminal block for the connecting
cables, S1/S2/S3
• Stop valves, gas and liquid for the
refrigerant connection
Fig. 4-3
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
insulation 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 tighten-
ing 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
Gas side Pipe size (mm)
Liquid side Pipe size (mm)
• When bending the pipes, be careful not to break them. Bend radii of 100 mm to
150 mm are 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 (Ap-
plied on site).
• When usual pipe sealing is used, refer to Table 1 for flaring of R410A refrigerant
pipes.
The size adjustment gauge can be used to confirm A measurements.
Table 1 (Fig. 4-2)
Copper pipe O.D.
Flare tool for R410A
(mm)
ø6.35 (1/4") 0 - 0.5
ø9.52 (3/8") 0 - 0.5
ø12.7 (1/2") 0 - 0.5
ø15.88 (5/8") 0 - 0.5
ø19.05 (3/4") 0 - 0.5
4.3. Refrigerant piping (Fig. 4-3)
Remove the service panel D (3 screws) and the front piping cover A (2 screws)
and rear piping cover B (2 screws).
1 Perform refrigerant piping connections for the indoor/outdoor unit, and the cyl-
inder/outdoor unit or hydrobox/outdoor unit when the outdoor unit's stop valves
are completely closed.
2 Vacuum-purge air from the indoor unit, and the cylinder unit or hydrobox, and
the connection piping.
3 After connecting the refrigerant pipes, check the connected pipes, the indoor
unit, and the cylinder unit or hydrobox, for gas leaks. (Refer to 4.4 Refrigerant
pipe airtight testing method)
4 A high-performance vacuum pump should be used at the stop valve service port
to maintain a vacuum for an adequate time (at least one hour after reaching –
101 kPa (5 Torr)) in order to vacuum dry the inside of the pipes. Always check
the degree of vacuum at the gauge manifold. If there is any moisture left in the
pipe, the degree of vacuum is sometimes not reached with short-time vacuum
application.
After vacuum drying, completely open the stop valves (both 2 sets of liquid and
gas) for the outdoor unit. This completely links the refrigerant circuits in the in-
door unit, the cylinder unit or hydrobox, and the outdoor unit.
• If the vacuum drying is inadequate, air and water vapor remain in the refriger-
ant circuits and can cause abnormal rise of high pressure, abnormal drop of
low pressure, deterioration of the refrigerating machine oil due to moisture, etc.
• 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.
• 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 connec-
tion sections to prevent water from entering the thermal insulation.
[15.88
[9.52
A (mm)
Flare tool for R22·R407C
Clutch type
1.0 - 1.5
1.0 - 1.5
1.0 - 1.5
1.0 - 1.5
1.0 - 1.5