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English
6. REFRIGERANT PIPING WORK
•
For the outdoor unit refrigerant piping, refer to the installa-
tion manual attached to the outdoor unit.
•
Carry out insulation of both gas and liquid refrigerant piping
securely. If not insulated, it may cause water leakage. For
gas piping, use insulation material of which heat resistant
temperature is not less than 250°F (120°C).
For use under high humidity, strengthen the insulation ma-
terial for refrigerant piping. If not strengthened, the surface
of insulation material may sweat.
•
Before installation work, make sure that the refrigerant is
R410A. (Unless the refrigerant is R410A, the nor mal opera-
tion cannot be expected.)
CAUTION
This air conditioner is a dedicated model for refriger-
ant R410A. Make sure to meet the require ments shown
below and carry out installation work.
• Use dedicated piping cutters and flaring tools for
R410A.
• When making a flare connection, coat the flared in
-
ner surface only with ether oil or ester oil.
• Use only the flare nuts attached to the air condition
-
er. If other flare nuts are used, it may cause refriger
-
ant leakage.
•
To prevent contamination or moisture from getting
into the piping, take measures such as pinch ing or
taping the pipings.
Do not mix substance other than the specified refrig
-
erant such as air into the refrigeration circuit.
If the refrigerant leaks during the work, ventilate the
room.
•
The refrigerant is pre-charged in the outdoor unit.
•
When connecting the pipings to the air conditioner,
make sure to use a spanner and a torque wrench as
shown in
Fig. 9
.
•
For the dimension of flared part and the tightening
torque, refer to the Table 2.
•
When making a flare connection, coat the flared inner
surface only with ether oil or ester oil.
(Refer to Fig. 10)
Then, turn the flare nut 3 to 4 times with your hand and
screw in the nut.
Torque wrench
Spanner
Flare nut
Union joint
Fig. 9
Coat the flared inner surface
only with ether oil or ester oil
Fig. 10
Table 2
Piping
size
[in. (mm)]
Tightening
torque
[lbf·ft. (N·m)]
Dimension for
processing flare
A [in. (mm)]
Flare shape
[in. (mm)]
f
1/4
(6.4)
10.4–12.7
(15.7±1.5)
0.342–0.358
(8.9±0.2)
90°±2°
A
45°±2°
R0.016-0.031
(0.4-0.8)
f
3/8
(9.5)
24.1–29.4
(36.3±3.6)
0.504–0.520
(13.0±0.2)
f
1/2
(12.7)
36.5–44.5
(54.9±5.4)
0.638–0.654
(16.4±0.2)
f
5/8
(15.9)
45.6–55.6
(68.6±6.8)
0.760–0.776
(19.5±0.2)
CAUTION
Do not have oil adhere to the screw fixing part of resin
parts.
If oil adheres, it may weaken the strength of screwed part.
Do not tighten flare nuts too tight.
If a flare nut cracks, the refrigerant may leak.
•
If there is no torque wrench, use Table 3 as a rule of
thumb.
When tightening a flare nut with a spanner harder and
harder, there is a point where the tightening torque sud-
denly increases.
From that position, tighten the nut additionally at the
angle shown in Table 3.
After the work is finished, check securely that there is no
gas leak.
If the nut is not tightened as instructed, it may cause
slow refrigerant leak and result in malfunction (such as
does not cool or heat).
Table 3
Piping size
[in. (mm)]
Tightening
angle
Recommended arm length of
tool used
f
1/4 (6.4)
60°–90°
Approx. 6 in. (150 mm)
f
3/8 (9.5)
60°–90°
Approx. 8 in. (200 mm)
f
1/2 (12.7)
30°–60°
Approx. 10 in. (250 mm)
f
5/8 (15.9)
30°–60°
Approx. 12 in. (300 mm)
CAUTION
Insulation of field piping must be carried out up to the
connection inside the casing.
If the piping is exposed to the atmosphere, it may cause
sweating, burn due to touching the piping, electric shocks
or a fire due to the wiring touching the piping.
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