Safety Precaution - Mitsubishi Electric Mr. Slim PCA Series Service Manual

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SAFETY PRECAUTION

2-1. ALWAYS OBSERVE FOR SAFETY
Before obtaining access to terminal, all supply
circuits must be disconnected.
2-2. CAUTIONS RELATED TO NEW REFRIGERANT
Cautions for units utilising refrigerant R407C
Do not use the existing refrigerant piping.
The old refrigerant and lubricant in the existing piping
contains a large amount of chlorine which may cause the
lubricant deterioration of the new unit.
Use "low residual oil piping"
If there is a large amount of residual oil (hydraulic oil, etc.)
inside the piping and joints, deterioration of the lubricant
will result.
Store the piping to be used indoors during
installation, and keep both ends of the piping
sealed until just before brazing. (Leave elbow
joints, etc. in their packaging.)
If dust, dirt, or water enters the refrigerant cycle,
deterioration of the oil and compressor trouble may result.
The refrigerant oil applied to flare and flange
connections must be ester oil, ether oil or
alkylbenzene oil in a small amount.
If large amount of mineral oil enter, that can cause
deterioration of refrigerant oil etc.
Use liquid refrigerant to charge 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 R407C.
If another refrigerant (R22, etc.) is used, the chlorine in the
refrigerant may cause the lubricant deterioration.
Use a vacuum pump with a reverse flow check valve.
The vacuum pump oil may flow back into the refrigerant
cycle and cause the lubricant deterioration.
Ventilate the room if refrigerant leaks during
operation. If refrigerant comes into contact with
a flame, poisonous gases will be released.
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