McQuay MWSC 010 Series Manual page 38

Refrigerant Piping Work
Refrigerant piping is important in particular. Refrigeration cycle of the split air conditioner is realized by the perfect
piping work.
Piping length and elevation
If the piping is too long, both the capacity and reliability of unit will drop. As the number of bends increase, resistance
to fl ow of refrigerant system increases, thus lowering cooling capacity and as a result the compressor may become
defective. Always choose the shortest path and follow the recommendation as tabulated.
Model
Number
Max. Length, L
Max. Elevation H
Max. No. Of bends
Liquid pipe size
Gas pipe size
t For cooling unit, need to add external accumulator (recommended 6kg accumulator).
A. Outdoor lower than indoor unit
Liquid check trapper
Outdoor unit
Installation of pipe
All system piping should be installed in accordance with local ordinances. The piping should be designed with a
minimum number of bends and changes in elevation to keep costs to a minimum and unit performance to a maximum.
A good installation should include the followings:
ó Vibration eliminators to reduce vibration and noise transmission to the building.
ó Shut-off valves are required to isolate the unit from the piping system during service.
ó Manual or automatic air vent valve at the high points of the system.
ó Some means to maintaining adequate system pressure (e.g. regulating valve and /or expansion tank )
ó Install temperature and pressure indicators at the unit pipe to aid in servicing and troubleshooting
ó Install a strainer to remove foreign matter from the water before it enters the pumps, it should be located far
enough from the upstream of pump to prevent cavitation at the inlet.
MWSC MWSC
010B/BR 015B/BR
7m 10m
5m 8m
10 10
1/4" 1/4"
3/8" 1/2"
Indoor unit
Note
MWSC MWSC
020B/BR 025B/BR
15m 15m
8m 8m
10 10
1/4" 3/8"
5/8" 5/8"
B. Outdoor unit higher than indoor unit
Outdoor unit
Liquid pipe
Gas pipe
Page 37
MWSC MWSC
030B/BR 050B/BR
20m 20m
10m 10m
10 10
3/8" 3/8"
5/8" 3/4"
Oil trapper
(Set one per six meter)
Indoor unit