Pumping Down - LG LA121HPMI Service Manual

Troubleshooting Guide

Pumping Down

Indoor unit
Purge the air
• Procedure
(1) Confirm that both the 2-way and 3-way
valves are set to the open position.
– Remove the valve stem caps and confirm
that the valve stems are in the raised posi-
tion.
– Be sure to use a hexagonal wrench to
operate the valve stems.
(2) Operate the unit for 10 to 15 minutes.
(3) Stop operation and wait for 3 minutes,
then connect the charge set to the service
port of the 3-way valve.
– Connect the charge hose with the push pin
to the service port.
(4) Air purging of the charge hose.
– Open the low-pressure valve on the charge
set slightly to air purge from the charge
hose.
(5) Set the 2-way valve to the closed position.
44 Room Air Conditioner
Liquid side
Gas side
Lo
CLOSE CLOSE
Open
2-Way
valve
Closed
3-Way
valve
(6) Operate the air conditioner at the cooling
cycle and stop it when the gauge indi-
cates 1kg/cm 2
(7) Immediately set the 3-way valve to the
closed position.
– Do this quickly so that the gauge ends up
indicating 3 to 5kg/cm
(8) Disconnect the charge set, and mount the
2-way and 3-way valve's 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.
Do not use the existing charge set for R-22.
It is necessary to use new charge set for R-
410A. The pressure of R-410A is 1.6 times
higher than that of R-22. Thus, the high pres-
sure side gauge of charge set should be used
higher pressure gauge of 50kg/cm
Outdoor unit
g.
2 g.
2 range.