Daikin FXKQ25MVE, Installation Manual

Page: 7 / 14

English 5
(When using a heat pump, the temperature of the gas piping
can reach up to approximately 120°C, so use insulation which is
sufficiently resistant.)
〈〈〈〈
Also, in cases where the temperature and humidity of the
refrigerant piping sections might exceed 30°C or RH80 %,
reinforce the refrigerant insulation. (20 mm or thicker) Con-
densation may form on the surface of the insulating material.
〉〉〉〉
〈〈〈〈
Before ringging tubes, check which type of refrigerant is
used. Proper operation is not possible if the types of refrig-
erant are not the same.
〉〉〉〉
CAUTION
• Use a pipe cutter and flare suitable for the type of refrigerant.
• Apply ester oil or ether oil around the flare portions
before connecting.
• To prevent dust, moisuture or other foreign matter from infil-
trating the tube, either pinch the end or cover it with tape.
• Do not allow anything other than the designated refrig-
erant to get mixed into the freezing cycle, such as air,
etc. If any refrigerant gas leaks while working on the
unit, ventilate the room thoroughly right away
.
• The outdoor unit is charged with refrigerant.
• Be sure to use both a spanner and torque wrench together,
as shown in the drawing, when connecting or disconnecting
pipes to/from the unit.
• Refer to the Table 3 for the dimensionons of flare not spaces.
• When connecting the flare nut, coat the flare section (both
inside and outside) with ester oil or ether oil, rotate three or
four times first, then screw in.
• Refer to the Table 3 for tightening torque.
Overtightening may damage the flare.
• Check the pipe connector for gas leaks, then insulate it as
shown in the drawing.
• Wrap only the gas line side with the sealing pad. Bend the pad
over the insulation for fitting (union) from above.
CAUTION
Over-tightening may damage the flare and cause a refriger-
ant leakage.
Use “ Tabel 4 ” as a reference if a torque wrench is not available.
Once work is complete, make sure there is no gas leaking. As
the flare nut is tightened with the wrench, the torque will sud-
denly increase. From that position, tighten the nut to the angle
shown on “ Tabel 4 ”.
• Make absolutely sure to execute heat insulation works on the
pipe-connecting section after checking gas leakage by thor-
oughly studying the following figure and using the attached
heat insulating materials for fitting. (Fasten both ends with
the clamps (accessory).)
• Wrap the sealing pad (accessory) only around the insulation
for the joints on the gas piping side.
CAUTION
Be sure to insulate any field piping all the way to the piping
connection inside the unit. Any exposed piping may cause
condensation or burns if touched.
CAUTION
CAUTION TO BE TAKEN WHEN BRAZING REFRIGER-
ANT PIPING
Do not use flux when brazing refrigerant piping. Therefore,
use the phosphor copper brazing filter metal (BCuP) which
does not require flux.
(Flux has extremely harmful infulence on refrigerant piping
sysems. For instance, if the chlorine based flux is used, it will
cause pipe corrosion or, in particular, if the flux contains fluo-
rine, it will damage the refrigerant oil.)
• Before brazing local refrigerant piping, nitrogen gas shall be
blown through the piping to expel air from the piping.
If your brazing is done without nitrogen gas blowing, a large
amount of oxide film develops inside the piping, and could
cause system malfunction.
• When brazing the refrigerant piping, only begin brazing after
having carried out nitrogen substitution or while inserting
nitrogen into the refrigerant piping. Once this is done, con-
nect the indoor unit with a flared or a flanged connection.
• Nitrogen should be set to 0.02 Mpa (0.2 kg/cm
2
) with a pres-
sure-reducing valve if brazing while inserting nitrogen into
the piping.
NOTE
The flare nuts used must be those included with the
main body.
• Refer to Table 3 for tightening torque.
Table 3
Ester oil or ether oil.
Torque wrench
Spanner
Piping union
Flare nut
Pipe
size
Tightening torque
Flare
dimensions
A (mm)
Flare
φ
6.4
(1/4”)
14.2 – 17.2N·m
(144 – 176 kgf·cm)
8.7 – 9.1
φ
9.5
(3/8”)
32.7 – 39.9N·m
(333 – 407 kgf·cm)
12.8 – 13.2
φ
12.7
(1/2”)
49.5 – 60.3N·m
(504 – 616 kgf·cm)
16.2 – 16.6
φ
15.9
(5/8”)
61.8 – 75.4N·m
(630 – 770 kgf·cm)
19.3 – 19.7
Small sealing pad
(accessory)
(accessory)
Gas pipe
Liquid pipe
Insulation
for fitting
Clamp
(× 6 accessory)
Refrigerant
piping
Part to be
brazed
Taping
Pressure-
reducing
valve
hands valve
Nitrogen
Nitrogen
A
45
0
Ⳳ
2
0
R0.4-0.8
90
0
Ⳳ
2
0
01_EN_3P086156-8F.fm Page 5 Wednesday, March 19, 2003 6:55 PM