54
Outdoor Unit
(2) Vacuum
Vacuum drying should be made from the service port provided on the outdoor unitʼs service valve to the vac-
uum pump commonly used for Liquid pipe, Low Pressure Gas pipes, High Pressure Gas pipe. (Make Vac-
uum from Liquid pipe, Low Pressure Gas pipes, High Pressure Gas 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).
1. Evacuate the system from the liquid and gas pipes with a vacuum pump for over 2 hrs and bring the sys-
tem to -100.7kPa.
After maintaining system under that condition for over 1 hr, confirm the vacuum gauge rises. The system
may contain moisture or leak.
2. Following should be executed if there is a possibility of moisture remaining 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 nitro-
gen 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.
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 refrigerant, the refrigerant cycle may malfunction and
the unit may be damaged.
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.
Indoor unit
Slave 1 outdoor unit
Master outdoor unit
Liquide pipe
High Pressure
Gas pipe
High Pressure
Gas pipe
Liquide pipe
Low Pressure
Gas pipe
Low Pressure
Gas pipe
Liquid side
Gas side
Close
Close
Close
Close
Close
Close
Vacuum
pump
Vacuum
pump
HR unit
Note : Always add an appropriate amount of refrigerant. (For the refrigerant additional 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.)
Refrigerant piping system
Summary of Contents for Multi V ARUB Series
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