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English
REFRIGERANT PIPING WORK
6.
CAUTION
<To piping technician>
Make sure to open the stop valves after fi nishing the
•
piping work. (Refer to the table shown in “ 6-7 Additional
refrigerant charge”.)
(Operating the air conditioner with the stop valve shut
may damage the compressor.)
Use R410A to add refrigerant. (The R410A refrigerant
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cylinder has a pink stripe painted around it.)
All fi eld piping must be installed by a licensed refrigeration
technician and must comply with relevant local and national
regulations.
BRAZING REFRIGERANT PIPING
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Do not use fl ux when brazing copper-to copper refrigerant
piping.
(Particularly for the HFC refrigerant piping) Therefore, use
the phosphor copper brazing fi ller metal (BCuP) which does
not require fl ux.
(Flux has an extremely negative effect on refrigerant piping
systems. For instance, if chlorine based fl ux is used, it will
cause pipe corrosion. Flux containing fl uorine will damage
refrigeration oil.)
NOTE
Maximum piping length between the outdoor and indoor unit:
•
Indoor unit
FAQ
FCQ
FHQ
FTQ
Max. piping length
164 ft.
98 ft.
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 such as SUNISO and moisture) from
mixing into the system.
(The screw specifi cations differ for R410A and R407C.)
Vacuum pump (use a 2-stage vacuum pump with a non-
return valve):
Make sure the pump oil does not fl ow oppositely into the
1.
system while the pump is not working.
Use a vacuum pump which can evacuate to –14.6 psi.
2.
Selection of piping material
6-1
Foreign materials inside pipes (including oils for fabrication)
1.
must be 0.14gr/10ft. or less.
Use the following material specifi cation for refrigerant
2.
pipping:
Construction material: Phosphoric acid deoxidized seam-
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less copper for refrigerant.
Size: liquid pipe:
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φ
3/8"
gas
pipe:
φ
5/8"
Protection of piping
6-2
Protect the piping to prevent moisture and dusts from com-
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ing into the piping.
Especially, pay attention when passing the piping through a
•
hole or connecting the end of piping to the outdoor.
Location
Working period
Protection method
Outdoor
1 month or more
Pinch pipes
Less than 1 month
Pinch or tape pipes
Indoor
Regardless of period
Piping connection
6-3
For handling of stop valves, refer to “Stop valve opera-
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tion method” in “6-7 Additional refrigerant charge”.
Only use the fl are nuts attached to the stop valves.
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Using different fl are nuts may cause the refrigerant to
leak.
Be sure to perform a nitrogen blow when brazing.
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(Brazing without performing nitrogen replacement or releasing
nitrogen into the piping will create large quantities of oxidized
fi lm inside the pipes, adversely affecting valves and compressor
in the refrigerating system and preventing normal operation.)
DANGER
Use of oxygen could cause an explosion resulting in severe
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injury or death. Only use nitrogen gas.
Refrigerant gas may produce toxic gas if it comes in contact
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with fi re such as from a fan heater, stove or cooking device.
Exposure to this gas could cause severe injury or death.
NOTE
When brazing with blowing nitrogen, set the nitrogen pres-
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sure to 2.9 psi or less by using a pressure reducing valve.
Location to
be brazed
Taping
Refrigerant
piping
Nitrogen
Regulator
Manual valve
Nitrogen
CAUTION
Do not use anti-oxidants when brazing.
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Residue can clog pipes and break the unit.
Do not let any refrigerant other than the specifi ed refrigerant
enter the refrigerant system.
Do not let any gas such as air enter the refrigerant system.
〈
Precautions when connecting the piping
〉
See the following table for fl are dimensions.
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When connecting the fl are nuts, apply refrigeration oil to the
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inside of the fl ares and turn them three or four times at fi rst.
(Use ester oil or ether oil.)
See the following table for tightening torque. (Applying too
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much torque may cause the fl ares to crack.)
After connecting all the piping perform a gas leak check by
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using nitrogen.
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