Mitsubishi Electric CITY MULTI PUHY-P-YKB-A1 Manuel D'installation page 25

Pipes B,C,D
Total capacity of indoor units
140 or below
141 to 200
201 to 300
301 to 400
401 to 650
651 to 800
801 or above
Pipes a,b,c,d,e
Capacity index of indoor unit
20, 25, 32, 40, 50
63, 71, 80, 100, 125, 140
200
250
9-5. Piping connections and valve operations
Before heating the brazed sections, remove the gas and oil that are trapped in the pipes.
- Failure to do so may generate fire, resulting in serious injury.
Ventilate the room while servicing the unit.
- If the refrigerant leaks, oxygen deficiency may result. If the leaked refrigerant comes in contact
with a heat source, toxic gas will be generated.
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.
Keep the service valves closed until refrigerant charging is completed.
- Failure to do so will damage the unit.
Place a wet towel on the service valves before brazing the pipes to keep the temperature of
the valves from rising above 120ºC (248ºF).
- Failure to do so may result in equipment damage.
Keep the flame out of contact with the cables and metal sheet when brazing the pipes.
- Failure to do so may result in burnout or 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.
KD79S703H01
[mm (in)]
Pipe
Liquid Gas
ø9.52 (ø3/8) ø15.88 (ø5/8)
ø9.52 (ø3/8) ø19.05 (ø3/4)
ø9.52 (ø3/8) ø22.2 (ø7/8)
ø12.7 (ø1/2) ø28.58 (ø1-1/8)
ø15.88 (ø5/8) ø28.58 (ø1-1/8)
ø19.05 (ø3/4) ø34.93 (ø1-3/8)
ø19.05 (ø3/4) ø41.28 (ø1-5/8)
[mm (in)]
Pipe
Liquid Gas
ø6.35 (ø1/4) ø12.7 (ø1/2)
ø9.52 (ø3/8) ø15.88 (ø5/8)
ø9.52 (ø3/8) ø19.05 (ø3/4)
ø9.52 (ø3/8) ø22.2 (ø7/8)
GB-23