Simultaneous twin
Allowable pipe length (m)
Total length
Branch piping
Outdoor unit
•
+
•
1
2
2
•
+
•
1
3
3
Maximum
Maximum
GP80, 110
50
15
GP140
50
15
Outdoor unit
Main pipe
Gas side
GP80, 110
15.9
GP140
15.9
Figure of simultaneous twin
Indoor unit
Indoor unit
Outdoor unit
2
3
1
EN-161
Height difference (m)
Branch piping
Indoor-outdoor H
•
–
3
2
Indoor unit:
Outdoor unit:
Maximum
Upper
Upper
10
30
10
30
Pipe diameter (mm)
Branch piping
Liquid side
Gas side
Liquid side
9.5
12.7
6.4
9.5
15.9
9.5
H
6
AIR PURGING
Airtight Test
Indoor-indoor
(Δh)
After completing the refrigerant piping work, perform an airtight test. Connect a nitrogen gas cylinder and pressurize
the pipes with nitrogen gas as follows to conduct the airtight test.
30
0.5
30
0.5
Number of bent
Charge port
portions
10 or less
10 or less
Gas leak check
Step 1....Pressurize to 0.5 MPa (5 kg/cm
Step 2....Pressurize to 1.5 MPa (15 kg/cm
Step 3....Pressurize to 4.15 MPa (42 kg/cm
(However, note that when the ambient temperature differs during pressurization and after 24 hours, the pressure will
change by approximately 0.01 MPa (0.1 kg/cm
If the pressure drops in steps 1 through 3, check the connections for leakage.
Check for leaks with foaming liquid, etc., take steps to fix the leaks such as brazing the pipes again and tightening
the flare nuts, and then perform the airtight test again.
* After the airtight test is completed, evacuate the nitrogen gas.
Air Purge
With respect to the preservation of the terrestrial
environment, adopt "Vacuum pump" to purge air
(Evacuate air in the connecting pipes) when installing the
unit.
• Do not discharge the refrigerant gas to the
atmosphere to preserve the terrestrial environment.
• Use a vacuum pump to discharge the air (nitrogen,
etc.) that remains in the set. If air remains, the capacity
may decrease.
For the vacuum pump, be sure to use one with a
backflow preventer so that the oil in the pump does not
backflow into the pipe of the air conditioner when the
pump stops.
(If oil in the vacuum pump is put in an air conditioner
including R32, it may cause trouble with the refrigeration
cycle.)
- 81 -
Low pressure gauge
High pressure gauge
Gauge manifold
V
V
L
H
Pressure reducing
valve
2
G) for 5 minutes or longer.
2
G) for 5 minutes or longer.
2
G) for 24 hours. ................ Micro leaks can be discovered.
2
G) per 1°C, so this should be compensated.)
CAUTION
Never use oxygen, flammable gas,
or noxious gas for the airtight test.
Nitrogen gas
Major leaks can be discovered.
Compound pressure gauge
Pressure gauge
–101 kPa
Gauge manifold valve
(–76 cmHg)
Handle High
Handle Low
(Keep fully closed)
Charge hose
Charge hose
(For R32 or R410A
(For R32 or R410A
only)
only)
Vacuum
pump adapter
for backflow
prevention
(For R32 or
Vacuum
pump
Charge port
R410A only)
(Valve core
(Setting pin))
Packed valve at gas side
EN-162