– 14 –
EN
CAUTION
When the refrigerant pipe is long, provide support
brackets at intervals of 2.5 m to 3 m to clamp the
refrigerant pipe. Otherwise, abnormal sound may be
generated.
■
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.
CAUTION
IMPORTANT 4 POINTS FOR PIPING WORK
1. Reusable mechanical connectors and
fl
ared
joints are not allowed indoors. When mechanical
connectors are reused indoors, sealing parts shall
be renewed. When
fl
ared joints are reused indoors,
the
fl
are 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
Model
Pipe size (mm)
Gas side
Liquid side
HM56
Ø12.7
Ø6.4
HM80, HM90,
HM110, HM140,
HM160
Ø15.9
Ø9.5
■
Connecting refrigerant piping
Flaring
y
Cut the pipe with a pipe cutter.
Remove burrs completely.
Remaining burrs may cause gas leakage.
y
Insert a
fl
are nut into the pipe, and
fl
are the pipe.
As the
fl
aring sizes of R32 differ from those of
refrigerant R22, the
fl
are tools newly manufactured
for R32 are recommended.
However, the conventional tools can be used by
adjusting projection margin of the copper pipe.
Projection margin in
fl
aring: B (Unit: mm)
Outer dia. of
copper pipe
Tool used
Conventional
tool used
6.4, 9.5
0.5 to 1.1
0.5 to 1.1
12.7, 15.9
0.5 to 1.1
1.5 to 2.0
B
Flaring diameter size: A (Unit: mm)
Outer dia. of copper pipe
A
+0
-0.4
6.4
9.1
9.5
13.2
12.7
16.6
15.9
19.7
A
CAUTION
y
Do not scratch the inner surface of the
fl
ared part
when removing burrs.
y
Flare processing under the condition of scratches
on the inner surface of
fl
are processing part will
cause refrigerant gas leak.
y
Check that the
fl
ared part is not scratched,
deformed, stepped, or
fl
attened, and that there
are no chips adhered or other problems, after
fl
are
processing.
y
Do not apply refrigerating machine oil to the
fl
are
surface.
* In case of
fl
aring with the conventional
fl
are tool,
pull it out approx. 0.5 mm more than that for R22
to djust to the speci
fi
ed
fl
are size. The copper pipe
gauge is useful for adjusting projection margin size.
y
The sealed gas was sealed at the atmospheric
pressure so when the
fl
are nut is removed, there
will no “whooshing” sound: This is normal and is not
indicative of trouble.
y
Use two wrenches to connect the indoor unit pipe.
Work using double spanner
y
Use the tightening torque levels as listed in the
following table.
Outer dia. of connecting
pipe (mm)
Tightening torque (N•m)
6.4
14 to 18
9.5
34 to 42
12.7
49 to 61
15.9
63 to 77
4
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
fl
are nut as far as possible with your
fi
ngers. Then
tighten the nut with a spanner and torque wrench as
shown in the
fi
gure.
CAUTION
Tightening with an excessive torque may crack the
nut depending on installation conditions.
■
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.
y
Do not use the refrigerant sealed in the outdoor unit
for evacuation.
REQUIREMENT
For the tools such as charge hose, etc., use those
manufactured exclusively for R32.
Refrigerant amount to be added
For addition of the refrigerant, add refrigerant
“R32” referring to the attached Installation Manual of
outdoor unit.
Use a scale to charge the refrigerant of speci
fi
ed
amount.
REQUIREMENT
y
Charging an excessive or too little amount of
refrigerant causes a trouble of the compressor.
Charge the refrigerant of speci
fi
ed amount.
y
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
fi
x 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, R134a, R410A, etc.).
7
Refrigerant
piping
