– 52 –
5
REFRIGERANT PIPING AND EVACUATING
Refrigerant piping
1. If the outdoor units are to be mounted on a wall,
make sure that the supporting platform is
sufficiently strong. The platform should be
designed and manufactured to maintain its
strength over a long period of time, and sufficient
consideration should be given to ensuring that the
outdoor unit will not fall.
2. Use copper pipe with 0.8 mm or more
thickness.
3. Flare nut and flare works are different from those
of the conventional refrigerant.
Take out the flare nut attached to the main unit of
the air conditioner, and use it.
CAUTION
IMPORTANT 4 POINTS FOR PIPING WORK
1. Remove dust and moisture from the inside of
the connecting pipes.
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)
Permissible piping length and heat
They vary according to the outdoor unit.
For details, refer to the Installation Manual attached to
the outdoor unit.
Flaring
Insert a flare nut into the pipe, and flare the pipe.
As the flaring sizes of R410A differ from those of
refrigerant R22, the flare tools newly manufactured for
R410A are recommended.
However, the conventional tools can be used by
adjusting projection margin of the copper pipe.
• Projection margin in flaring :
B (Unit : mm)
Rigid (Clutch type)
Imperial (Wing nut type)
B
A
Flare at
indoor
unit side
Flare at
outdoor
unit side
Half union
Flare nut
Externally
threaded side
Internally
threaded side
Use a wrench to secure.
Use a torque wrench to tighten.
• Flaring diam. meter size :
A (Unit : mm)
Outer diam. of copper pipe
6.4
9.5
12.7
A
R410A
R22
9.1
9.0
13.2
13.0
16.6
16.2
* In case of flaring for R410A with the conventional
flare tool, pull it out approx. 0.5 mm more than that
for R22 to adjust to the specified flare size.
The copper pipe gauge is useful for adjusting
projection margin size.
Tightening connection
CAUTION
• Do not apply excessive torque. Otherwise, the
nut may crack depending on the conditions.
(Unit : N•m)
Outer diam. of copper pipe
6.4 mm (diam.)
9.5 mm (diam.)
12.7 mm (diam.)
Tightening torque
14 to 18 (1.4 to 1.8 kgf•m)
33 to 42 (3.3 to 4.2 kgf•m)
50 to 62 (5.0 to 6.2 kgf•m)
• Tightening torque of flare pipe connections
Pressure of R410A is higher than that of R22.
(Approx. 1.6 times)
Therefore, using a torque wrench, tighten the flare
pipe connecting sections which connect the indoor
and outdoor units of the
specified tightening torque.
Incorrect connections may
cause not only a gas
leak, but also a trouble
of the refrigeration cycle.
Align the centers 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.
+0
- 0.4
Outer diam. of
copper pipe
6.4
9.5
12.7
R410A tool used
R410A
R22
0 to 0.5
(Same as left)
0 to 0.5
(Same as left)
0 to 0.5
(Same as left)
Conventional tool used
R410A
R22
1.0 to 1.5
0.5 to 1.0
1.0 to 1.5
0.5 to 1.0
1.0 to 1.5
0.5 to 1.0
Outer diam. of copper pipe
6.4
9.5
12.7
R410A
R22
1.5 to 2.0
1.0 to 1.5
1.5 to 2.0
1.0 to 1.5
2.0 to 2.5
1.5 to 2.0
Summary of Contents for RAS-M10SMUCV-E
Page 71: ... 71 11 7 P C Board Layout ...
