20
ENGLISH
[unit:mm]
Leak test
Leak test should be made by pressurizing nitrogen gas to 3.8
MPa(38.7kgf/cm
2
). If the pressure does not drop for 24 hours, the sys-
tem passes the test. If the pressure drops, check where the nitrogen
leaks. For the test method, refer to the following figure. (Make a test
with the service valves closed. Be also sure to pressurize liquid pipe,
gas pipe and high/low pressure common pipe)
The test result can be judged good if the pressure has not be reduced
after leaving for about one day after completion of nitrogen gas pres-
surization.
Indoor unit
Slave 2 outside unit
Slave 1 outside unit
Master outside unit
Close
Close
Close
High/low pressure
common pipe
High/low pressure
common pipe
High/low pressure
common pipe
Liquide pipe
Gas pipe
Liquide pipe
Gas pipe
Liquide pipe
Gas pipe
Close
Liquid side
Gas side
Nitrogen gas
cylinder
Nitrogen gas
cylinder
Close
Close
Close
Close
Close
Leak Test and Vacuum drying
Header
Models
Gas pipe
Liquid pipe
4 branch
ARBL054
120
150
360
120
ID15.88
ID12.7
ID12.7
ID15.88
ID15.88
ID19.05
120
120
150
360
ID9.52
ID9.52
ID6.35
ID6.35
ID9.52
ID12.7
7 branch
ARBL057
540
ID15.88
ID19.05
120
150
120
ID15.88
ID12.7
ID15.88
ID12.7
ID15.88
ID19.05
540
ID9.52
ID12.7
120 150
120
ID6.35
ID9.52
ID9.52
ID12.7
4 branch
ARBL104
120
150
400
160
ID15.88
ID12.7
ID19.05
ID15.88
ID22.2
ID28.58 ID25.4
120
120
150
360
ID9.52
ID9.52
ID6.35
ID6.35
ID9.52
ID12.7
7 branch
ARBL107
120
150
160
580
ID19.05
ID15.88
ID15.88
ID12.7
ID22.2
ID28.58 ID25.4
120
150
700
120
ID6.35
ID9.52
ID9.52
ID6.35
ID9.52
ID12.7
10 branch
ARBL1010
120
150
160
760
ID19.05
ID15.88
ID15.88
ID12.7
ID22.2
ID28.58
ID25.4
120
150
160
760
ID19.05
ID15.88
ID15.88
ID12.7
ID22.2
ID28.58
ID25.4
10 branch
ARBL2010
120
150
182
775
ID19.05
ID15.88
ID15.88
ID12.7
ID28.58
ID31.8
ID34.9
120
150
107
60*9=540
700
ID6.35
ID9.52
ID19.05
ID15.88
ID9.52
ID6.35
NOTE
!
If the ambient temperature differs between the time when pressure is
applied and when the pressure drop is checked, apply the following
correction factor
There is a pressure change of approximately 0.1 kg/cm
2
(0.01 MPa) for
each 1°C of temperature difference.
Correction= (Temp. at the time of pressurization – Temp. at the time
of check) X 0.1
For example: Temperature at the time of pressurization
(3.8 MPa) is 27 °C
24 hour later: 3.73 MPa, 20°C
In this case the pressure drop of 0.07 is because of tem-
perature drop And hence there is no leakage in pipe oc-
curred.
CAUTION
To prevent the nitrogen from entering the refrigeration system in
the liquid state, the top of the cylinder must be at higher position
than the bottom when you pressurize the system.
Usually the cylinder is used in a vertical standing position.
!
WARNING
Use a vacuum pump or Inert(nitrogen) gas when doing leakage test
or air purge. Do not compress air or Oxygen and do not use Flamma-
ble gases. Otherwise, it may cause fire or explosion.
- There is the risk of death, injury, fire or explosion.
!
Vacuum
Vacuum drying should be made from the service port provided on the outside
unit ’s service valve to the vacuum pump commonly used for liquid pipe, gas
pipe and high/low pressure common pipe. (Make Vacuum from liquid pipe, gas
pipe and high/low pressure common pipe with the service valve closed.)
* Never perform air purging using refrigerant.
• Vacuum drying: Use a vacuum pump that can evacuate to -100.7kPa
(5 Torr, -755mmHg).
- Evacuate the system from the liquid and gas pipes with a vacuum
pump for over 2 hrs and bring the system to -100.7kPa. After main-
taining system under that condition for over 1 hr, confirm the vacuum
gauge rises. The system may contain moisture or leak.
- Following should be executed if there is a possibility of moisture re-
maining inside the pipe.
(Rainwater may enter the pipe during work in the rainy season or over
a long period of time)
After evacuating the system for 2 hrs, give pressure to the system to
0.05MPa(vacuum break) with nitrogen gas and then evacuate it again
with the vacuum pump for 1hr to -100.7kPa(vacuum drying). If the
system cannot be evacuated to -100.7kPa within 2 hrs, repeat the
steps of vacuum break and its drying. Finally, check if the vacuum
gauge does not rise or not, after maintaining the system in vacuum
for 1 hr.
Scale
Use a graviometer. (One that can measure
down to 0.1kg). If you are unable to
prepare such a high-precision gravimeter
you may use a charge cylinder.
Vacuum pump
Vacuum pump
Indoor unit
Slave 2 outside unit
Slave 1 outside unit
Master outside unit
Close
Close
High/low pressure
common pipe
Liquide pipe
Gas pipe
High/low pressure
common pipe
Liquide pipe
Gas pipe
High/low pressure
common pipe
Liquide pipe
Gas pipe
Close
Liquid side
Gas side
Close
Close
Close
Close
Close
Close
Содержание Multi V ARWN Series
Страница 37: ......
