English
7
• Perform nitrogen substituent or apply nitrogen into the
refrigerant piping (see NOTE 1) in the case of refrigerant
piping blazing (see NOTE 2). Then perform the flare con-
nection of the indoor unit.
(Refer to Fig. 7)
CAUTION
•
Do not use any antioxidant at the time of piping blazing.
The piping may be clogged with a residual antioxidant and
parts may malfunction.
NOTE
1.
At the time of blazing, set the pressure of nitrogen to
approximately 0.02 MPa (close to the pressure of a
breeze coming in contact with the cheek) with a decom-
pression valve.
2.
Do not use flux at the time of blazing and connecting the
refrigerant piping. Use a copper phosphorus brazing alloy
(BCuP-2: JIS Z 3264/BCu 93P-710/795: ISO3677), which
does not require flux, for blazing.
(Flux has a bad influence on the refrigerant piping. Chlo-
rine-based flux will cause piping corrosion. Furthermore, if
it contains fluorine, the flux will deteriorate refrigerant oil.)
• As for the branching of the refrigerant piping or refrigerant,
refer to the installation manual provided with the outdoor unit.
7.
DRAIN PIPING WORK
(1) Conduct drain piping work.
Check that the piping
ensures proper draining.
• Make sure that the diam-
eter of the piping exclud-
ing the rising part is the
same as or larger than
the diameter of the con-
necting pipe (vinyl chloride pipe with an outer diameter
of 32 mm and a nominal inner diameter of 25 mm).
• Make sure that the piping is short enough
with a down-
ward slope of at least 1/100
and that there is no air
bank formed. No drain trap is required.
CAUTION
• The drain piping will be clogged with water and water leak-
age may result if the water is accumulated in the drain piping.
• Conduct drain-up piping work if the gradient is insuffi-
cient.
• Attach a support bracket at 1 to 1.5 m intervals for the
prevention of piping deflection.
• Be sure to use the drain hose (2) and metal clamp (1).
Insert the drain hose (2) deep into the base of the
drain socket, and securely fasten the metal clamp (1)
within the taped part on the insertion front end of the
hose.
Be sure to fasten the screw of the metal clamp (1) until
the margin of the screw thread decreases to 4 mm or
less.
NOTE
Be sure to follow the instructions as below.
• Do not connect the drain piping directly to a sewer that
smells of ammonia.
The ammonia in the sewer may reach through the drain
piping and corrode the heat exchanger of the indoor unit.
• Do not bend or twist the provided drain hose (2) in order
not to impose excessive force on the hose. (Doing so
may result in water leakage.)
• Take the procedure shown in the following illustration to
perform concentrated drain piping.
• Select the diameter of the concentrated drain piping to
suit the capacity of equipment connecting to the concen-
trated drain piping (see the equipment design sheet).
Nitrogen
Refrigerant
piping
Part to be
brazed
Taping
Pressurereducing valve
hands
valve
Nitrogen
Fig. 7
Refrigerant
piping
Drain socket
Socket for
maintenance
(with rubber cap)
1 - 1.5 m
Support bracket
Downward slope of at least 1/100
(accessory)
(accessory)
Metal clamp (1)
Tape
Drain hose (2)
Concentrated drain piping
The drain piping will be clogged with water
and water leakage may result if the water is
accumulated in the drain piping.
Maintain
a downward slope of at least
1/100
so that no air bank will be formed.
0 - 467 mm
Ceiling slab
1 - 1.5 m
300 mm max.
700 mm max.
Support bracket
Drain-up piping
(field supply)
Adjustable
(467 mm max.)
Metal clamp (1) (accessory)
Drain hose (2) (accessory)
Drain hose (2) (accessory)
Horizontal or
upward slope
If there is an air bank, noise may be generated
as a result of a water backflow when the drain
pump comes to a stop.
Locate the drain hose horizontally
or with a little upward gradient.
01_EN_3PN06583-7N.fm Page 7 Saturday, February 28, 2009 3:02 PM
