Mitsubishi Electric CITY MULTI PUHY-P-YKB-A1 Manuel D'installation page 9

Use a vacuum pump with a check valve.
- If the vacuum pump oil flows back into the refrigerant lines, the refrigerant oil may deteriorate
and the compressor may malfunction.
Keep tools clean.
- If dust, dirt, or water accumulates on the charging hose or the flare processing tool, the
refrigerant will deteriorate and the compressor will malfunction.
Use refrigerant piping made of phosphorus deoxidized copper (copper and copper alloy
seamless pipes) that meets local requirements. Pipe joints should also meet local
requirements. Keep the inner and outer surfaces of the pipes clean and free of sulphur,
oxides, dust/dirt, shaving particles, oils, moisture, or any other contaminants.
- Contaminants on the inside of the refrigerant piping will cause the refrigerant oil to deteriorate
and cause the compressor to malfunction.
Store pipes indoors, and keep both ends of the pipes sealed until just before making a
flare connection or brazing. (Store elbows and other joints in plastic bags.)
- If dust, dirt, or water enters the refrigerant lines, the refrigerant oil will deteriorate and the
compressor will malfunction.
Braze the pipes with a nitrogen purge to avoid oxidation.
- Oxidized flux inside the refrigerant pipes will cause the refrigerant oil to deteriorate and cause
the compressor to malfunction.
Do not use existing refrigerant piping.
- The old refrigerant and refrigerant oil in the existing piping contain a large amount of chlorine,
which will cause the refrigerant oil in the new unit to deteriorate and cause the compressor to
malfunction.
Charge refrigerant in a liquid state.
- Charging refrigerant in the gaseous state will change the composition of the refrigerant and lead
to a performance drop.
Do not use a charging cylinder when charging refrigerant.
- The use of a charging cylinder may change the composition of the refrigerant and lead to a
performance drop.
If a large electric current flows due to a malfunction or faulty wiring, earth-leakage breakers
on the unit side and on the upstream side of the power supply system could both operate.
Depending on the importance of the system, separate the power supply system or take
protective coordination of breakers.
This appliance is intended to be used by expert or trained users in shops, in light industry
and on farms, or for commercial use by lay persons.
This appliance is not intended for use by persons (including children) with reduced
physical, sensory or mental capabilities, or lack of experience and knowledge, unless they
have been given supervision or instruction concerning use of the appliance by a person
responsible for their safety.
KD79S703H01
GB-7