Precautions For Devices That Use R407C Refrigerant - Mitsubishi Electric PUH-P200MYA Technical & Service Manual

¡ PRECAUTIONS FOR DEVICES THAT USE R407C REFRIGERANT
Do not use the existing refrigerant piping.
• A large amount of chlorine that may be contained in
the residual refrigerant and refrigerating machine oil
in the existing piping may cause the refrigerating
machine oil in the new unit to deteriorate.
Use refrigerant pipes made of phosphorus
deoxidized copper. Keep the inner and outer
surfaces of the pipes clean and free of such
contaminants as sulfur, oxides, dust, dirt, shaving
particles, oil, and water.
• These types of contaminants inside the refrigerant
pipes may cause the refrigerant oil to deteriorate.
Store the pipes to be installed indoors, and keep both
ends of the pipes sealed until immediately before
brazing. (Keep elbows and other joints wrapped in
plastic.)
• Infiltration of dust, dirt, or water into the refrigerant
system may cause the refrigerating machine oil to
deteriorate or cause the unit to malfunction.
Use a small amount of ester oil, ether oil, or
alkylbenzene to coat flares and flanges.
• Infiltration of a large amount of mineral oil may
cause the refrigerating machine oil to deteriorate.
Charge liquid refrigerant (as opposed to gaseous
refrigerant) into the system.
• If gaseous refrigerant is charged into the system, the
composition of the refrigerant in the cylinder will
change and may result in performance loss.
Only use refrigerant R407C.
• The use of other types of refrigerant that contain
chlorine (i.e. R22) may cause the refrigerating
machine oil to deteriorate.
Caution
Use a vacuum pump with a reverse-flow check valve.
• If a vacuum pump that is not equipped with a
reverse-flow check valve is used, the vacuum pump
oil may flow into the refrigerant cycle and cause the
refrigerating machine oil to deteriorate.
Prepare tools for exclusive use with R407C. Do not
use the following tools if they have been used with
the conventional refrigerant (gauge manifold,
charging hose, gas leak detector, reverse-flow
check valve, refrigerant charge base, vacuum
gauge, and refrigerant recovery equipment.).
• If the refrigerant or the refrigerating machine oil left
on these tools are mixed in with R407C, it may cause
the refrigerating machine oil to deteriorate.
• Infiltration of water may cause the refrigerating
machine oil to deteriorate.
• Gas leak detectors for conventional refrigerants will
not detect an R407C leak because R407C is free
of chlorine.
Do not use a charging cylinder.
• If a charging cylinder is used, the composition of the
refrigerant will change, and the unit may experience
power loss.
Exercise special care when handling the tools for
use with R407C.
• Infiltration of dust, dirt, or water into the refrigerant
system may cause the refrigerating machine oil to
deteriorate.
If the refrigerant leaks, recover the refrigerant in the
refrigerant cycle, then recharge the cycle with the
specified amount of the liquid refrigerant indicated
on the air conditioner.
• Since R407C is a nonazeotropic refrigerant, if addi-
tionally charged when the refrigerant leaked, the com-
position of the refrigerant in the refrigerant cycle will
change and result in a drop in performance or abnor-
mal stopping.
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