LG LA120HPI User Manual

Page of 76
Service Manual  57
Troubleshooting Guide 
1) Re-air purging 
(Re-installation)
• Procedure 
(1) Confirm that both the liquid side valve and the
gas side valve are set to the closed position. 
(2) Connect the charge set and a gas cylinder to
the service port of the Gas side valve. 
–  Leave the valve on the gas cylinder closed. 
(3) Air purging. 
–  Open the valves on the gas cylinder and the
charge set. Purge the air by loosening the flare
nut on the liquid side valve approximately 45°
for 3 seconds then closing it for 1 minute;
repeat 3 times. 
– After purging the air, use a torque wrench to
tighten the flare nut on liquid side valve.
(4) Check for gas leakage.
–  Check the flare connections for gas leakage.  
(5) Discharge the refrigerant. 
–  Close the valve on the gas cylinder and dis-
charge the refrigerant until the gauge indicates
3 to 5 kg/cm
2
g. 
(6) Disconnect the charge set and the gas cylin-
der, and set the Liquid side and Gas side
valves to the open position.
–  Be sure to use a hexagonal wrench to operate
the valve stems. 
(7) Mount the valve stem nuts and the service
port nut.
–  Use torque wrench to tighten the service port
nut to a torque of 1.8 kg.m.
– Be sure to check for gas leakage.  
* CAUTION: 
Do not leak the gas in the air during Air
Purging.
Lo
Closed
OPEN
Closed
Gas cylinder
Outdoor unit
Indoor unit
Liquid side
Gas side
CLOSE
3-Way
valve
3-Way
valve
Refrigerant