English
6
CAUTION
Over-tightening may damage the flare and cause a refriger-
ant leakage.
Use “ Table 2 ” 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 “ Table 2 ”.
• After checking the pipe-connection for gas leakage, be sure
to insulate the liquid and gas piping, referring to the figure
below.
• Wrap the sealing pad (field supply) 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.
NOTE
• Attached piping is needed for connecting gas piping. Use
attached piping according to the size of the piping to be con-
nected.
When connecting the included piping, use the included pip-
ing flange hex bolts accessory (9) and spring washers acces-
sory (10).
• Connect refrigerant piping and branching according to the
attached installation manuals that come with the outdoor
unit.
CAUTION
CAUTION TO BE TAKEN WHEN BRAZING REFRIGER-
ANT PIPING
Do not use flux when brazing refrigerant piping. Therefore,
use the phosphor copper brazing filler metal (BCuP-2/
B-Cu93P-710/795) 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
fluorine, 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 2.90PSI with a pressure-reducing
valve if brazing while inserting nitrogen into the piping.
Not recommendable but in case of emergency
You must use a torque wrench but if you are obliged to
install the unit without a torque wrench, you may follow the
installation method mentioned below.
After the work is finished, make sure to check that
there is no gas leak.
When you keep on tightening the flare nut with a spanner,
there is a point where the tightening torque suddenly
increases. From that position, further tighten the flare nut
the angle shown below:
Table 2
7.
DRAIN PIPING WORK
〈〈
Rig the drain pipe as shown below and take measures
against condensation. Improperly rigged piping could lead
to leaks and eventually wet furniture and belongings.
〉〉
〈〈
Insulate the drain hose inside the building.
〉〉
(1) Carry out the drain piping.
Indoor units to be
connected
Gas piping diameter
Liquid piping
diameter
FXMQ72MVJU
φ
3/4
Use attached piping.
φ
3/8
FXMQ96MVJU
φ
7/8
Use attached piping.
Sealing pad
(Field supply)
Insulation for fitting
(Field supply)
Gas pipe
Liquid pipe
(for gas line)
Clamp
(accessory (8))
Pipe size
Further tightening
angle
Recommended arm length of
tool
φ
1/4”
60 to 90 degrees
Approx. 5-7/8in.
φ
3/8”
60 to 90 degrees
Approx. 7-7/8in.
φ
1/2”
30 to 60 degrees
Approx. 9-13/16in.
φ
5/8”
30 to 60 degrees
Approx. 11-3/16in.
Nitrogen
Refrigerant
piping
Part to be
brazed
Taping
Pressurereducing valve
hands
valve
Nitrogen
Bottom of unit
Attached drain hose
01_EN_3P086156-13Y.fm Page 6 Wednesday, September 16, 2009 2:22 PM
