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Outdoor Unit
L
L
H
A
Indoor Unit
Sample Unit Connection
Maximum Pipe Length (L)
Maximum Height
Difference Between
Indoor and outdoor units (H)
Total length: 120m
Equivalent length: 150m
■
Selecting Refrigerant Pipes
< P250 Type >
A
Outdoor Unit
L
H
A
Indoor Unit
Total length: 120m
Equivalent length: 150m
< P500 Type >
Under 50m (Under 40m if the outdoor unit
is installed below the indoor unit. Under 15m
if the outdoor temperature is under 10˚C.)
Under 50m (Under 40m if the outdoor unit
is installed below the indoor unit. Under 15m
if the outdoor temperature is under 10˚C.)
Gas pipe:
ø
28.58
Liquid pipe:
ø
12.7
Gas pipe:
ø
28.58
✕
2
Liquid pipe:
ø
12.7
✕
2
Warning
Exercise caution so that refrigerant R407C does not leak around fire. When exposed to an open flame, refrigerant can
produce noxious gases and subject the personnel to gas poisoning. Provide adequate ventilation during welding. Also,
check for possible gas leak after the installation of refrigerant piping has been completed.
When using two refrigerant circuits, make sure that gas
pipes and liquid pipes do not get cross-connected to each
other by accident.
• Doing so will damage the unit.
• If refrigerant other than R407C is used or if air enters the
cycle, the system malfunctions and the pipes may
explode.
Do not use refrigerant other than R407C.
Store the piping to be used during installation indoors and
keep both ends of the piping sealed until immediately
before blazing. (Keep elbows and other joints wrapped in
plastic.)
• If refrigerant is contaminated with dust, dirt, or moisture,
refrigerator oil will deteriorate and problems with
compressor may result.
Use refrigerant pipes made of C1220 phosphorus deoxidized
copper categorized under H3300 (Copper and Copper Alloy
Seamless Pipes and Tubes), a standard set by JIS.
• Keep inner and outer surfaces of the pipes clean and free
of contaminants such as sulfur, oxides, dust/dirt, shaving
particles, oils, and moisture.
• Contaminants inside the refrigerant piping will deteriorate
the refrigerant oil.
Do not use a charging cylinder.
• The use of charging cylinder will change the composition of
the refrigerant and lead to power loss.
Do not use a charging cylinder.
• The use of charging cylinder will change the composition of
the refrigerant and lead to power loss.
Use liquid refrigerant to charge the circuit.
• Charging the system with gas refrigerant will change the
composition of the refrigerant in the cylinder and will lead to
a drop in performance.
Do not use the existing refrigerant piping.
• The old refrigerant and refrigerator oil in the existing piping
contain a large amount of chlorine, which may cause the
refrigerator oil of the new unit to deteriorate.
Caution
3
3
Restrictions on Refrigerant Pipe Length
There are two types of refrigerant circuits: one with one refrigerant circuit and another with two refrigerant circuits.
The former consists of refrigerant piping from one outdoor unit connected to an indoor unit (P250), and the latter
consists of refrigerant piping from two outdoor units connected to an indoor unit (P500). Use flange connection for
gas pipes, and use flare connection for liquid pipes for both indoor and outdoor units.
[1] Refrigerant Piping
