Safety Precaution - Mitsubishi Electric PUH-P1.6VGA Technical & Service Manual

SAFETY PRECAUTION

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Cautions for using with the outdoor unit which adopts R407C refrigerant.
· Do not use the existing refrigerant piping.
-The old refrigerant and refrigerant oil in the existing piping contains a large amount of chlorine which may cause the
refrigerant oil of the new unit to deteriorate.
· Do not use copper pipes which are broken, deformed or discolour .
In addition, be sure that the inner surfaces of the pipes are clean, free of hazardous sulphur and oxides, or have no dust /
dirt, shaving particles, oils, moisture or any other contamination.
-If there is a large amount of residual oil (hydraulic oil, etc.) inside the piping and joints, deterioration of the refrigerant oil will
result.
· 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 ester oil, ether oil or alkyl benzene (small amount) as the refrigerant oil to coat flares and flange connections.
-The refrigerant oil will degrade if it is mixed with a large amount of mineral oil.
Use liquid refrigerant to fill the system.
-If gas refrigerant is used to fill the system, the composition of the refrigerant in the cylinder will change and performance
may drop.
· Do not use a refrigerant other than R407C.
-If another refrigerant (R22, etc.) is used, the chlorine in the refrigerant may cause the refrigerant 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 refrigerant oil to deteriorate.
· Do not use the following tools that are used with conventional refrigerant.
(Gauge manifold , charge hose, gas leak detector, reverse flow check valve, refrigerant charge base, vacuum gauge,
refrigerant recovery equipment)
-If the conventional refrigerant and refrigerant oil are mixed in the R407C, the refrigerant may deteriorated.
-If water is mixed in the R407C, the refrigerant oil may deteriorate.
-Since R407C does not contain any chlorine, gas leak detectors for conventional refrigerant will not react to it.
· Do not use a charging cylinder.
-Using a charging cylinder may cause the refrigerant to deteriorate.
· Be especially careful when managing the tools.
-if dust, dirt, or water gets in the refrigerant cycle, the refrigerant may deteriorate.
· Do not use the drier which is sold in the field.
-The drier for R407C refrigerant is pre-attached to outdoor unit refrigerant circuit.
-Some drier in the field are not in conformity with R407C refrigerant .
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