7.
Refrigerant pipe size and allowable pipe length
7.1. General information
NOTE
The refrigerant R410A requires strict cautions for keeping the system
clean, dry and tight.
r Clean and dry: foreign materials (including mineral oils or moisture)
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r Tight: R410A does not contain any chlorine, does not destroy
the ozone layer, and does not reduce earth’s protection against
harmful ultraviolet radiation. R410A can contribute slightly to the
greenhouse effect if it is released. Therefore we should take special
attention to check the tightness of the installation.
7.2. Selection of piping material
NOTE
Piping and other pressure containing parts shall comply with the appli-
cable legislation and shall be suitable for refrigerant. Use phosphoric
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NOTE
r #NNƂGNFRKRKPIOWUVDGKPUVCNNGFD[CNKEGPUGFTGHTKIGTCVKQPVGEJPK-
cian and must comply with relevant local and national regulations.
r After piping work is complete, do not under any circumstances open
VJGUVQRXCNXGWPVKN(KGNFYKTKPIQPRCIG|CPF%JGEMKPIQH
FGXKEGCPFKPUVCNNCVKQPEQPFKVKQPUQPRCIG|CTGEQORNGVG
r &QPQVWUGƃWZYJGPDTC\KPIVJGTGHTKIGTCPVRKRKPI7UGVJGRJQU-
RJQTEQRRGTDTC\KPIƂNNGTOGVCN$%W2+51
YJKEJFQGUPQVTGSWKTGƃWZ(NWZJCUGZVTGOGN[PGICVKXGGHHGEVQP
TGHTKIGTCPVRKRKPIU[UVGOU(QTKPUVCPEGKHVJGEJNQTKPGDCUGFƃWZKU
WUGFKVYKNNECWUGRKRGEQTTQUKQPQTKPRCTVKEWNCTKHVJGƃWZEQPVCKPU
ƃWQTKPGKVYKNNFCOCIGVJGTGHTKIGTCPVQKN
r Use only pipes which are clean inside and outside and which do not
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other contamination. (Foreign materials inside pipes including oils
for fabrication must be 0.14 gr/10 ft. or less.)
r Use the following items for the refrigerant piping.
Material :,QKPVNGUURJQURJQTFGQZKFK\GFEQRRGTRKRG
Size : See 7.3. Selection of piping size to determine the correct
size.
Thickness : Select a thickness for the refrigerant piping which
complies with national and local laws.
r (QTRKRKPIYQTMHQNNQYVJGOCZKOWOVQNGTCVGFNGPIVJFKHHGTGPEGKP
height, and length after a branch indicated in the 7.5. System piping
(length) limitations.
r Outdoor unit multi connection piping kit and refrigerant branching
kit (sold separately) are needed for connection of piping between
outdoor units (in case of multi system) and piping branches.
r 7UGQPN[UGRCTCVGN[UQNFKVGOUUGNGEVGFURGEKƂECNN[CEEQTFKPIVQ
the outdoor unit multi connection piping kit, the refrigerant branch-
ing kit selection in the 7.4. Selection of refrigerant branch kits.
7.3. Selection of piping size
Determine the proper size referring to following tables and reference
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A
BBB
C
DF
G
E
x
y
b
a
3
12
45
1, 2 VRV indoor unit
3 BP unit (1 module system only)
4, 5 Mini-split indoor unit (1 module system only)
a, b Refrigerant branching kit
Z[ Outdoor unit multi connection piping kit
7.3.1. 2KRKPIDGVYGGPQWVFQQTWPKVCPFƂTUVTGHTKIGTCPV
branch kit: A, B, C
Choose from the following table in accordance with the outdoor unit
total capacity type, connected downstream.
Outdoor unit capacity
type
Piping outer diameter size
Gas pipe Liquid pipe
RXYQ72T type 3/4 in. (19.1 mm)
3/8 in. (9.5 mm)
RXYQ96T type 7/8 in. (22.2 mm)
RXYQ120, 144T type
1-1/8 in. (28.6 mm)
1/2 in. (12.7 mm)
RXYQ168-216T type
5/8 in. (15.9 mm)
RXYQ240T type
1-3/8 in. (34.9 mm)
RXYQ264-336T type
3/4 in. (19.1 mm)
RXYQ360-408T type 1-5/8 in. (41.3 mm)
7.3.2. Piping between refrigerant branch kits: D
Choose from the following table in accordance with the indoor unit
total capacity type, connected downstream. Do not let the connec-
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system model name.
Indoor unit
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Piping outer diameter size
Gas pipe Liquid pipe
< 54 5/8 in. (15.9 mm)
3/8 in. (9.5 mm)Űu < 72
3/4 in. (19.1 mm)
Űu < 111
7/8 in. (22.2 mm)
Űu < 162
1-1/8 in. (28.6 mm)
1/2 in. (12.7 mm)
Űu < 230
5/8 in. (15.9 mm)
Űu < 300
1-3/8 in. (34.9 mm)
3/4 in. (19.1 mm)
> 300 1-5/8 in. (41.3 mm)
Example:
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&QYPUVTGCOECRCEKV[HQT&ECRCEKV[KPFGZQHWPKVECRCEKV[KPFGZ
of unit 2