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20
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.
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
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.
Vacuum
Vacuum drying should be made from the service port provided on the outdoor
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.
Slave 1 outdoor unit
Vacuum
pump
Close
Close
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.
2
(0.01 MPa) for
Master outdoor unit
Close
Close
Liquid side
Indoor unit
Gas side
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.
NOTE
!
Always add an appropriate amount of refrigerant. (For the refrigerant addi-
tional charge)
Too much or too little refrigerant will cause trouble.
To use the Vacuum Mode
(If the Vacuum mode is set, all valves of Indoor units and Outdoor units will
be opened.)
WARNING
!
When installing and moving the air conditioner to another site,
recharge after perfect evacuation.
- If a different refrigerant or air is mixed with the original refriger-
ant, the refrigerant cycle may malfunction and the unit may be
damaged.
Vacuum Mode
This function is used for creating vacuum in the system after compres-
sor replacement, ODU parts replacement or IDU addition/replacement.
Vacuum mode setting method
DIP SWITCH
Master unit PCB DIP switch on : No.5
Select the mode using '▶', '◀' Button :
"SVC" Push the '●' button
Select the Function using '▶', '◀' Button : :
"Se3" Push the '●' button
Start the vacuum mode : "VACC"
ODU V/V open
ODU EEV open
IDU EEV open
Vacuum mode off method
Dip switch off and push the reset button on Master unit PCB
CAUTION
!
ODU operation stops during vacuum mode. Compressor can't
operate.
7-Segment
SW04C ( X : cancel)
SW03C (
: forward)
SW02C (
: backward
SW01C (
: confirm)
SW01D (reset)
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