Precautions For Devices That Use R410A Refrigerant - Mitsubishi Electric NTXAMT36A112AA Installation Manual

3.2. Precautions for devices that use R410A refrigerant

CAUTION
• Do not use the existing refrigerant piping.
– The old refrigerant and refrigeration oil in the existing piping contains a large amount
of chlorine which may cause the refrigerator oil of the new unit to deteriorate.
• Use refrigerant piping made of C1220 (Cu-DHP) phosphorus deoxidized copper as
specified in the JIS H3300 "Copper and copper alloy seamless pipes and tubes". In
addition, be sure that the inner and outer surfaces of the pipes are clean and free of
hazardous sulphur, oxides, dust/dirt, shaving particles, oils, moisture, or any other
contaminants.
– Contaminants on the inside of the refrigerant piping may cause the refrigerant residual
oil to deteriorate.
• Store the piping to be used during installation indoors and keep both ends of the piping
sealed until just before brazing. (Store elbows and other joints in a plastic bag.)
– If dust, dirt, or water enters the refrigerant cycle, deterioration of the oil and
compressor trouble may result.
• Use liquid refrigerant to fill the system.
– If gas refrigerant is used to seal the system, the composition of the refrigerant in the
cylinder will change and performance may drop.
• Do not use a refrigerant other than R410A.
– If another refrigerant is used, the chlorine in the refrigerant may cause the refrigerator
oil to deteriorate.
• Use a vacuum pump with a reverse flow check valve.
– The vacuum pump oil may flow back into the refrigerant cycle and cause the
refrigerator oil to deteriorate.
• Do not use the following tools that are used with conventional refrigerants.
– Gauge manifold, charge hose, gas leak detector, reverse flow check valve, refrigerant
charge base, vacuum gauge, refrigerant recovery equipment.
– If the conventional refrigerant and refrigeration oil are mixed in the R410A, the
refrigerant may deteriorate.
– If water is mixed in the R410A, the refrigeration oil may deteriorate.
– Since R410A does not contain any chlorine, gas leak detectors for conventional
refrigerant will not react to it.
– Do not use a charging cylinder. May cause the refrigerant to deteriorate.
• Be especially careful when managing the tools.
– If dust, dirt, or water gets in the refrigeration system, the refrigerant may deteriorate.
© 2020 Mitsubishi Electric Trane HVAC US LLC. All rights reserved.
NTXAMT12, 18, 24, 30, 36A112AA
10 Specifications are subject to change without notice.