LG ARUN096BT2 Installation Manual - Page 44

Refrigerant piping installation (2) 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 -14.6 psi. 1. Evacuate the system from the liquid and gas pipes with a vacuum pump for over 2 hrs and bring the system to -14.6 psi. 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 7.3 psi(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 -14.6 psi 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. Vacuum pump Slave 1 outdoor unit Close Close Master outdoor unit Close Close High/low pressure common pipe Liquide pipe Gas pipe High/low pressure common pipe Liquide pipe Gas pipe Vacuum pump Close Close Scale Use a graviometer. (One that can measure down to 0.22 lb). If you are unable to prepare such a high-precision gravimeter you may use a charge cylinder. Liquid side Indoor unit Gas side 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.) 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. 44 Outdoor Unit