6
English
(3) After checking for gas leaks, be sure to insulate the
pipe connections referring to Fig. 8.
•
Insulate using the insulation for fitting (3) (4) included with
the liquid and gas pipes. Besides, make sure the insula-
tion for fitting (3) (4) on the liquid and gas piping has its
seams facing up.
(Tighten both edges with clamp (9).)
•
For the gas piping, wrap the mid. sealing pad (6) over the
insulation for fitting (4) (flare nut part).
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.
•
When brazing the refrigerant piping, perform nitrogen
replacement first, or perform the brazing (CAUTION 2) while
feeding nitrogen into the refrigerant piping (CAUTION 1), and
finally connect the indoor unit using the flare connections.
(Refer to Fig. 9)
CAUTION
1. When brazing a pipe while feeding nitrogen inside the
pipe, make sure to set the nitrogen pressure to 0.02 MPa
using the pressure reducing valve.
(This pressure is such that breeze is blown to your cheek.)
2. Do not use a flux when brazing the refrigerant pipe joints.
Use phosphor copper brazer (BCuP-2: JIS Z 3264/B-Cu93P-
710/795: ISO 3677) which does not require flux. (Using a flux
containing chlorine may cause the piping to corrode. Using a
welding flux containing fluorine may cause the refrigerant lubri-
cant to deteriorate, and affect adversely the refrigerant piping
system.)
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
(1) Install the drain piping.
•
Make sure the drain works properly.
•
The diameter of the drain piping should be greater than or
equal to the diameter of the connecting pipe (vinyl tube; pipe
size: 20 mm; outer dimension: 26 mm).
(not including the riser)
•
Keep the drain piping short and sloping downwards at a gra-
dient of at least 1/100 to prevent air pockets from forming.
(Refer to Fig. 10)
CAUTION
Water accumulating in the drain piping can cause the
drain to clog.
Gas pipe
Piping insulation
material (main unit)
Attach to base
Flare nut connection
Turn seams up
Mid. sealing pad (6)
Insulation for fitting (4)
Gas Piping Insulation Procedure
Liquid Piping Insulation Procedure
(accessory)
Clamp (9)
Piping insulation material
(Field supply)
Clamp (9) (accessory)
Flare nut connection
Turn seams up
Piping insulation material
(Field supply)
Piping insulation material
(main unit)
Attach to base
Main unit
Fig. 8
Liquid pipe
Insulation for fitting (3)
(accessory)
(accessory)
(accessory)
Wrap over the top of
the flare nut connection.
Main unit
Refrigerant piping
Part to be brazed
Taping
Pressure-reducing valve
hands
valve
Nitrogen
Nitrogen
Fig. 9
Pipe size
Further tightening angle
Recommended arm
length of tool
φ
6.4 (1/4”)
60 to 90 degrees
Approx. 150mm
φ
9.5 (3/8”)
60 to 90 degrees
Approx. 200mm
φ
12.7 (1/2”)
30 to 60 degrees
Approx. 250mm
φ
15.9 (5/8”)
30 to 60 degrees
Approx. 300mm
Drain pipe connection hole
Refrigerant pipes
Service drain hole
(with rubber cap)
100mm or
more
Central drain piping
(with a slope of at least 1/100)
Fig. 10
01_EN_3PN06588-2C.fm Page 6 Tuesday, November 29, 2005 2:25 PM
