Mitsubishi Electric CITY MULTI PUHY-P-YSMF-B Manuel D'installation page 13

Warning:
When installing and moving the air conditioner to another site, do not charge the it with a refrigerant different from the refrigerant (R407C)
specified on the unit.
- If a different refrigerant or air is mixed with the original refrigerant, the refrigerant cycle may malfunction and the unit may be damaged.
Caution:
• Use refrigerant piping made of C1220T-OL phosphorus deoxidized copper. 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 contaminant.
- Contaminants on the inside of the refrigerant piping may cause the refrigerant residual oil to deteriorate.
• Use liquid refrigerant for sealing.
- Sealing with gas refrigerant will change the composition of the refrigerant in the cylinder and reduce the unit's performance.
• Never use existing refrigerant piping.
- The large amount of chlorine in conventional refrigerant and refrigerator oil in the existing piping will cause the new refrigerant to deteriorate.
• Store the piping to be used during installation indoors and keep both ends of the piping sealed until just before brazing.
- If dust, dirt, or water gets into the refrigerant cycle, the oil will deteriorate and the compressor may fail.
• Do not use a charging cylinder.
- Using a charging cylinder may cause the refrigerant to deteriorate.
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