AZQS100~1Y1B
Split system air conditioners
4P332194-1B – 2015.01
Installation manual
8
9.
Precautions on refrigerant piping
Do not allow anything other than the designated refrigerant 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.
Use R410A only when adding refrigerant
Installation tools:
Make sure to use installation tools (gauge manifold, charge
hose, etc.) that are exclusively used for R410A installations to
withstand the pressure and to prevent foreign materials (e.g.
mineral oils and moisture) from mixing into the system.
Vacuum pump:
Use a 2-stage vacuum pump with a non-return valve
Make sure the pump oil does not flow oppositely into the system
while the pump is not working.
Use a vacuum pump which can evacuate to –100.7 kPa (5 Torr,
–755 mm Hg).
During tests never pressurize the appliances with a pressure
higher than the maximum allowable pressure (see unit name
plate: PS).
In order to prevent dirt, liquid or dust from entering the piping,
cure the piping with a pinch or taping.
Great caution is needed when passing copper tubes through
walls.
Piping should be mounted so that the flare is not subjected to
mechanical stress.
9.1.
Flaring guidelines
Flares should not be re-used. New ones should be made in
order to prevent leaks.
Use a pipe cutter and flare tool suitable for the refrigerant used.
Only use the flare nuts included with the unit. Using different
flare nuts may cause the refrigerant to leak.
Please refer to the table for flaring dimensions and tightening
torques (too much tightening will result in splitting the flare).
When connecting the flare nut, coat the flare inner surface with
ether oil or with ester oil and initially tighten 3 or 4 turns by hand
before tightening firmly.
When loosening a flare nut, always use two wrenches together.
When connecting the piping, always use a spanner and torque
wrench together to tighten the flare nut to prevent flare nut
cracking and leaks.
1
Torque wrench
2
Spanner
3
Piping union
4
Flare nut
Not recommended, but in case of emergency
Should you be forced to connect the piping without a torque
wrench, follow the following installation method:
Tighten the flare nut using a spanner until the tightening
torque suddenly increases.
From that position further tighten the flare nut to the angle
listed below:
9.2.
Brazing guidelines
Make sure to blow through with nitrogen when brazing.
Blowing through with nitrogen prevents the creation of large
quantities of oxidized film on the inside of the piping. An oxidized
film adversely affects valves and compressors in the
refrigerating system and prevents proper operation.
The nitrogen pressure should be set to 0.02 MPa (i.e., just
enough so it can be felt on the skin) with a pressure-reducing
valve. Refer to
figure 2
.
1
Refrigerant piping
2
Part to be brazed
3
Taping
4
Manual valve
5
Pressure-reducing valve
6
Nitrogen
Do not use anti-oxidants when brazing the pipe joints.
Residue can clog pipes and break equipment.
Do not use flux when brazing copper-to-copper refrigerant
piping. Use phosphor copper brazing filler alloy (BCuP) which
does not require flux.
Flux has an extremely harmful influence on refrigerant piping
systems. For instance, if chlorine based flux is used, it will cause
pipe corrosion or, in particular, if the flux contains fluorine, it will
deteriorate the refrigerant oil.
9.3.
Stop valve operation
Cautions on handling the stop valve
Make sure to keep both stop valves open during operation.
The figure below shows the name of each part required in
handling the stop valve.
The stop valve is factory closed.
Place
Installation period
Protection method
Outdoor unit
More than a month
Pinch the pipe
Less than a month
Pinch or tape the pipe
Indoor unit
Regardless of the
period
Piping size
(mm)
Tightening
torque (N•m)
Flare dimensions A
(mm)
Flare shape
(mm)
Ø6.4
15~17
8.7~9.1
Ø9.5
33~39
12.8~13.2
Ø12.7
50~60
16.2~16.6
Ø15.9
63~75
19.3~19.7
A
90
2
45
2
R=0.4~0.8
Piping size
(mm)
Further tightening angle
(degrees)
Recommended arm length
of spanner (mm)
Ø6.4
60~90
150
Ø9.5
200
Ø12.7
30~60
250
Ø15.9
300
1
2
4
3
1
2
3
4
1
Service port and service port cap
2
Valve stem
3
Field piping connection
4
Stem cap
