Refrigerant Piping Work - Daikin FCQ18AAVJU Installation Manual

CAUTION
• Install the indoor unit horizontally.
If the indoor unit is inclined and the drain piping side gets
high, it may cause malfunction of a float switch and results
in water leakage.
• Attach nuts on the upper and lower side of hanger
bracket.
If there is no upper nut and the lower nut is over-tightened,
the hanger bracket and the top plate malfunction and cre-
ate unwanted noise.
• Do not insert materials other than those specified
into the clearance between the hanger bracket and
the washer for hanger bracket (3).
Unless the washers are properly attached, the suspen-
sion bolts may come off from the hanger bracket.
WARNING
The indoor unit must be securely installed on a
place that can withstand the weight.
If the strength is insufficient, the indoor unit may fall
down and cause injuries.

5. 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 or operation will malfunction.
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 only the flared
inner surface with ether oil or ester oil.
• Use only the flare nuts attached to the indoor unit.
If other flare nuts are used, it may cause refrigerant
leakage.
• To prevent contamination or moisture from getting
into the piping, take measures such as pinch ing or
taping the piping.
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 piping to the air conditioner, make
sure to use a spanner and a torque wrench as shown in
Fig. 10.
• Using a tool other than a spanner may destroy the flare
nut thread, resulting in refrigerant leakage due to poor
tightening.
English
• For the dimension of flared part and the tightening
torque, refer to the Table 2.
• Use the flare nuts attached to the piping of indoor unit.
• When making a flare connection, coat only the flared
inner surface with ether oil or ester oil.
(Refer to Fig. 11)
Then, turn the flare nut 3 to 4 times with your hand and
screw in the nut.
Torque wrench
Flare nut
Union joint
Fig. 10
Coat only the flared inner
surface with ether oil or ester oil
Fig. 11
Table 2
Piping Tightening Dimension for
size torque processing flare
[in. (mm)] [lbf·ft. (N·m)] A [in. (mm)]
f 3/8
24.1 – 29.4 0.504 – 0.520
(9.5) (36.3±3.6) (13.0±0.2)
f 5/8
45.6 – 55.6 0.760 – 0.776
(15.9) (68.6±6.8) (19.5±0.2)
CAUTION
Do not let 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 much.
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 the 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 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).
Spanner
Flare shape
[in. (mm)]
R0.016-0.031
(0.4-0.8)
6