Piping Connections And Valve Operations - Mitsubishi Electric CITY MULTI PURY-HP-TNU-A Manuel D'installation

Pipes A, A , A
1 2
Combination unit
Unit model
Unit 1
HP72T/YNU -
HP96T/YNU -
HP120T/YNU -
HP144T/YSNU P72
HP192T/YSNU P96
HP240T/YSNU P120
*1 If the combination units 1 and 2 are in a different order as listed in the table, make sure to use the pipes of appropriate size for the situation.
Pipe B
Total capacity of indoor units
30 or below
Pipes C, D, E
Total model number of downstream
indoor units
72 or below
73 to 108
109 to 126
127 to 144
145 to 168
Pipes a,b,c,d,e,f
Capacity index of indoor unit
05, 06, 08, 12, 15, 18
24, 27, 30, 36, 48, 54
72
96
Pipes g, h, i, j
Capacity index of indoor unit
36
48
54
72
96

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.
WT09112X02
Pipe A
Unit 2 High-pressure
- ø15.88 (5/8)
- ø19.05 (3/4)
- ø19.05 (3/4)
P72 ø22.2 (7/8)
P96 ø22.2 (7/8)
P120 ø28.58 (1-1/8)
[mm (in)]
Pipe
Liquid Gas
ø9.52 (ø3/8) ø15.88 (ø5/8)
Pipe
High-pressure Low-pressure
ø15.88 (ø5/8) ø19.05 (ø3/4)
ø19.05 (ø3/4) ø22.2 (ø7/8)
ø19.05 (ø3/4) ø28.58 (ø1-1/8)
ø22.2 (ø7/8) ø28.58 (ø1-1/8)
ø22.2 (ø7/8) ø28.58 (ø1-1/8)
[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)
Liquid pipe
g h
ø9.52 (ø3/8) ø9.52 (ø3/8)
ø9.52 (ø3/8) ø9.52 (ø3/8)
ø9.52 (ø3/8) ø9.52 (ø3/8)
ø9.52 (ø3/8) ø9.52 (ø3/8)
ø9.52 (ø3/8) ø9.52 (ø3/8)
Pipe A *
1
Low-pressure High-pressure
ø19.05 (3/4) -
ø22.2 (7/8) -
ø28.58 (1-1/8) -
ø28.58 (1-1/8) ø15.88 (5/8)
ø28.58 (1-1/8) ø19.05 (3/4)
ø34.93 (1-3/8) ø19.05 (3/4)
[mm (in)]
Liquid
ø9.52 (ø3/8)
ø9.52 (ø3/8)
ø12.7 (ø1/2)
ø12.7 (ø1/2)
ø15.88 (ø5/8)
[mm (in)]
Gas pipe
i j
ø15.88 (ø5/8) ø15.88 (ø5/8)
ø15.88 (ø5/8) ø15.88 (ø5/8)
ø15.88 (ø5/8) ø15.88 (ø5/8)
ø19.05 (ø3/4) ø15.88 (ø5/8)
ø22.2 (ø7/8) ø15.88 (ø5/8)
GB-19
Pipe A *
1
2
Low-pressure High-pressure
- -
- -
- -
ø19.05 (3/4) ø15.88 (5/8)
ø22.2 (7/8) ø19.05 (3/4)
ø28.58 (1-1/8) ø19.05 (3/4)
[mm (in)]
1
Low-pressure
-
-
-
ø19.05 (3/4)
ø22.2 (7/8)
ø28.58 (1-1/8)