Daikin FXHQ-M, Engineeiring Data

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EDUS39-600-F5 Installation
FXHQ-M 23
6-1 GENERAL INSTRUCTIONS
• For refrigerant pipe of outdoor units, see the installa-
tion manual attached to the outdoor unit.
• Execute thermal insulation work completely on both
sides of the gas pipe and the li q uid pipe or a water leak
may occur.
.
(The temperature of the gas pipe can reach up to
approximately 250°F, so use insulation pipe cover
that is sufficiently resistant.)
• In cases where the temperature and humidity of the
refrigerant pipe sections might exceed 86°F or RH
80%, reinforce the thermal insulation (3/4 in. or thicker)
or condensate may form on the surface of the insula-
tion pipe cover.
Before refrigerant pipe work, check which type of
refrigerant is used. Proper operation is not possible if
the types of refrigerant are not the same.
6-2 CONNECTING THE REFRIGERANT PIPE
• Ensure outdoor unit is charged w ith refrigerant.
• Use copper alloy seamless pipes.
• Be sure to use both a spanner and tor
q ue w rench together,
as sho w n in the dra w ing, w hen connecting or disconnect-
ing pipes to/from the unit. (Refer to Fig. 13)
• Refer to Table 2 to determine the proper tightening tor q ue.
• Refer to Table 2 for the dimensions of flare shape.
• When connecting the flare nut, coat the flare section (both
inside and outside) w ith ester oil or ether oil, rotate three or
• four times first, then scre w in. (Refer to Fig. 14)
• Use the flare nut include w ith the main body of the unit.
CAUTION
• Oil must not adhere to any e q uipment other than a flare. If
oil adheres to resin or other parts, deterioration may occur..
Table 2
CAUTION
• Overtightening may damage the flare and cause a refriger-
ant leakage.
Not recommended but in case of emergency
You must use a tor q ue w rench but if one is not available,
you can use the follo w ing installation method:
When you keep tightening the flare nut w ith a spanner, there is
a point w here the tightening tor q ue suddenly increases. From
that position, further tighten the flare nut the angle sho w n
belo w :
Table 3
After the work is finished, make sure to check that
there is no gas leak.
6-3 BRAZING REFRIGERANT PIPING
• Do not use flux w hen brazing refrigerant pipe. Use phos-
phor copper brazing filler metal (BCuP) w hich does not
re q uire flux.
• Flux has an extremely negative effect on refrigerant piping
systems. For instance, if chlorine based flux is used, it w ill
cause pipe corrosion. If the flux contains fluorine, it w ill
damage the refrigerant oil.
• Before brazing local refrigerant pipe, nitrogen gas shall be
blo w n through the pipe to expel air from the pipe.
If brazing is done w ithout nitrogen gas blo w ing, a large
amount of oxide film develops inside the pipe w hich can
cause system malfunction.
• When brazing the refrigerant pipe, only begin brazing after
having carried out nitrogen substitution or w hile inserting
nitrogen into the refrigerant pipe. Once this is done, con-
nect the indoor unit
w ith a flared or a flanged connection.
• N itrogen should be set to 2.9 psi w ith a pressure-reducing
valve if brazing w hile inserting nitrogen into the pipe.
(Refer to Fig. 15)
Tor q ue w rench
Flare nut
Pipe union
Spanner
Fig. 13
Fig. 14
Ester oil or ether oil.
Pipe size
(in.)
Tightening
tor q ue (ft.lbf)
Flare dimen-
sions A
(in.)
Flare shape (in.)
φ
1/4 10.4–12.7 0.342–0.358
φ
3/8 24.1–29.4 0.504–0.520
φ
1/2 36.5–44.5 0.638–0.654
φ
5/8 45.6–55.6 0.760–0.776
Pipe size (in.) Further tightening angle Recommended arm length of tool (in.)
φ
1/4 60 to 90 degrees Approx. 5 7/8
φ
3/8 60 to 90 degrees Approx. 7 7/8
φ
1/2 30 to 60 degrees Approx. 9 13/16
φ
5/8 30 to 60 degrees Approx. 11 13/16
R0.016-0.031
A
90˚± 2˚
45˚±2˚
Refrigerant pipe
Part to be
brazed
Taping
Pressure-reducing
valve
hands valve
N itrogen
N itrogen
Fig. 15