Refrigerant Piping Work - Daikin RZQ18PVJU (9) Installation Manual

6.

REFRIGERANT PIPING WORK

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
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
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
Max. piping length
• 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):
1.
Make sure the pump oil does not fl ow oppositely into the
system while the pump is not working.
2.
Use a vacuum pump which can evacuate to –14.6 psi.
6-1 Selection of piping material
1.
Foreign materials inside pipes (including oils for fabrication)
must be 0.14gr/10ft. or less.
2.
Use the following material specifi cation for refrigerant
pipping:
• Construction material: Phosphoric acid deoxidized seam-
less copper for refrigerant.
φ3/8"
• Size: liquid pipe:
gas pipe: φ5/8"
6-2 Protection of piping
• Protect the piping to prevent moisture and dusts from com-
ing into the piping.
• Especially, pay attention when passing the piping through a
hole or connecting the end of piping to the outdoor.
9
FAQ
FCQ FTQ
FHQ
164 ft. 98 ft.
Location Working period
1 month or more
Outdoor
Less than 1 month
Indoor Regardless of period
6-3 Piping connection
• For handling of stop valves, refer to "Stop valve opera-
tion method" in "6-7 Additional refrigerant charge".
• Only use the fl are nuts attached to the stop valves.
Using different fl are nuts may cause the refrigerant to
leak.
• Be sure to perform a nitrogen blow when brazing.
(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
injury or death. Only use nitrogen gas.
• Refrigerant gas may produce toxic gas if it comes in contact
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-
sure to 2.9 psi or less by using a pressure reducing valve.
Refrigerant
Location to
piping
be brazed
Nitrogen
Taping
Manual valve
CAUTION
• Do not use anti-oxidants when brazing.
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.
• When connecting the fl are nuts, apply refrigeration oil to the
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
much torque may cause the fl ares to crack.)
• After connecting all the piping perform a gas leak check by
using nitrogen.
Protection method
Pinch pipes
Pinch or tape pipes
Regulator
Nitrogen
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