– 54 –
7
Refrigerant piping
CAUTION
Use flare nuts that are included with the unit. Using
different flare nuts may cause refrigerant gas leakage.
Refrigerant piping
Use the following item for the refrigerant piping.
Material: Seamless phosphorous deoxidized
copper pipe.
Ø6.35, Ø9.52, Ø12.7 Wall thickness 0.8 mm or more
REQUIREMENT
When the refrigerant pipe is long, provide support brackets
at intervals of 2.5 to 3 m to clamp the refrigerant pipe.
Otherwise, abnormal sound may be generated.
CAUTION
IMPORTANT 4 POINTS FOR PIPING WORK
1. Reusable mechanical connectors and flared joints are
not allowed indoors. When mechanical connectors are
reused indoors, sealing parts shall be renewed. When
flared joints are reused indoors, the flare part shall be
refabricated.
2. Tight connection (between pipes and unit)
3. Evacuate the air in the connecting pipes using VACUUM
PUMP.
4. Check the gas leakage. (Connected points)
Pipe size
Permissible piping length and
height difference
They vary according to the outdoor unit.
For details, refer to the Installation Manual attached to the
outdoor unit.
◆
Flaring
▼
Projection margin in flaring : B (Unit : mm)
Rigid (Clutch type)
▼
Flaring dia. meter size : A (Unit : mm)
CAUTION
• Do not scratch the inner surface of the flared part
when removing burrs.
• Flare processing under the condition of scratches on
the inner surface of flare processing part will cause
refrigerant gas leak.
• Check that the flared part is not scratched, deformed,
stepped, or flattened, and that there are no chips
adhered or other problems, after flare processing.
• Do not apply refrigerating machine oil to the flare
surface.
RAV-
Pipe size (mm)
Liquid side
Gas side
RM30 type
Ø6.4
Ø9.5
RM40, 56 type
Ø6.4
Ø12.7
• Cut the pipe with a pipe cutter.
Remove burrs completely.
Remaining burrs may cause gas leakage.
• Insert a flare nut into the pipe,
and flare the pipe.
As the flaring sizes of R32 or
R410A differ from those of
refrigerant R22, the flare tools
newly manufactured for R32 or
R410A are recommended.
However, the conventional
tools can be used by adjusting
projection margin of the
copper pipe.
Outer dia. of
copper pipe
R32 or R410A
tool used
Conventional
tool used
6.4, 9.5
0 to 0.5
1.5 to 2.0
12.7
Outer diam. of
copper pipe
A
6.4
9.1
9.5
13.2
12.7
16.6
B
+0
–0.4
A
Tightening connection
CAUTION
Do not apply excessive torque. Otherwise, the nut may
crack depending on the conditions.
▼
Tightening torque of flare pipe connections
Incorrect connections may cause not only a gas leak,
but also a trouble of the refrigeration cycle.
Align the centres of the connecting pipes and tighten
the flare nut as far as possible with your fingers. Then
tighten the nut with a spanner and torque wrench as
shown in the figure.
REQUIREMENT
Tightening with an excessive torque may crack the nut
depending on installation conditions.
Tighten the nut within the specified tightening torque.
Evacuation
Perform vacuuming from the charge port of valve of the
outdoor unit by using a vacuum pump.
For details, follow to the Installation Manual attached to
the outdoor unit.
• Do not use the refrigerant sealed in the outdoor unit
for evacuation.
REQUIREMENT
For the tools such as charge hose, use those
manufactured exclusively for R32 or R410A.
Refrigerant amount to be added
For addition of the refrigerant, add refrigerant “R32 or
R410A” referring to the attached Installation Manual of
outdoor unit.
Use a scale to charge the refrigerant of specified
amount.
REQUIREMENT
• Charging an excessive or too little amount of
refrigerant causes a trouble of the compressor.
Charge the refrigerant of specified amount.
• A personnel who charged the refrigerant should write
down the pipe length and the added refrigerant
amount in the F-GAS label of the outdoor unit. It is
necessary to fix the compressor and refrigeration
cycle malfunction.
Open the valve fully
Open the valve of the outdoor unit fully. A 4 mm-
hexagonal wrench is required for opening the valve.
For details, refer to the Installation Manual attached to
the outdoor unit.
Gas leak check
Check with a leak detector or soap water whether gas
leaks or not, from the pipe connecting section or cap of
the valve.
REQUIREMENT
Use a leak detector manufactured exclusively for HFC
refrigerant (R32, R410A, R134a).
Unit: N•m
Outer dia. of copper pipe
Tightening torque
6.4 mm
14 - 18
9.5 mm
34 - 42
12.7 mm
49 - 61
Work using two spanner
107-EN
108-EN
Summary of Contents for RAV-RM301SDT-E
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