Make sure there is not any dirt or water before connecting
the piping to the outdoor units.
Wash the piping with high pressure nitrogen, never use
refrigerant of outdoor unit.
4.7 Remove Dirt or Water in the Piping
4.8 Airtight Test
Charge pressured nitrogen after connecting indoor/outdoor unit
piping to do airtight test.
CAUTION
1. Pressured nitrogen [ 4.3MPa (44kg/cm ) for R410A] should be
used in the airtight test.
2
2. Tighten high pressure/low pressure valves before
applying pressured nitrogen.
3. Apply pressure from air vent mouth on the hight pressure/
low pressure valves.
4. The high pressure/low pressure valves are closed when
applying pressured nitrogen.
5. The airtight test should never use any oxygen,
flammable gas or poisonous gas.
8
installation manual
4.9 Air Purge with Vacuum Pump
4.10 Refrigerant Amount to be Added
Using vacuum pump to do the vacuum,never using refrigerant to
expel the air.
Vacuuming should be done from both liquid side and gas side
simultaneously.
Calculate the added refrigerant according to the diameter and the
length of the liquid side pipe of the outdoor unit/indoor unit
connection.
NOTE
Additional refrigerant volume of divergent pipe is 0.1kg
per item (Consider the liquid side of divergent pipe only)
Liquid Side Piping
Diameter
Refrigerant to be Added
Permeter Piping
Φ9.5
Φ12.7
Φ15.9
Φ19.1
Φ22.2
0.054kg
0.110kg
0.170kg
0.260kg
0.360kg
Φ6.4
0.022kg
Table 4-12
When the outdoor unit connects 1 indoor unit:
The second cennect method
Indoor unit
D
1
1
1
1
1
1
Outdoor unit
$
%
'
(
&
E
F
H
I
G
/
/
/
/
/
D
ro
p
H
EI
G
H
T
b
e
tw
e
e
n
i
n
d
o
o
r
u
n
it
a
n
d
u
u
td
o
o
r
u
n
it
Maximum pipe equivalent length
Pipe length(From the nearest branch
pipe equivalent length
(From the first line branch pipe)
Maximum pipe equivalent length
In
d
o
o
r
U
n
it
t
o
I
n
d
o
o
r
U
n
it
D
ro
p
H
e
ih
g
t
The First Line Branch Pipe
Fig.4-8
