LG LSU120HE - Manual (Page 32)

32 Room Air Conditioner
Evacuation
• Connect the charge hose end described in the
preceding steps to the vacuum pump to evacuate
the tubing and indoor unit.
Confirm the "Lo" knob of the manifold valve is
open. Then, run the vacuum pump.
The operation time for evacuation varies with tub-
ing length and capacity of the pump. The follow-
ing table shows the time required for evacuation.
• When the desired vacuum is reached, close the
"Lo" knob of the manifold valve and stop the vac-
uum pump.
Finishing the job
• With a service valve wrench, turn the valve stem
of liquid side valve counter-clockwise to fully
open the valve.
• Turn the valve stem of gas side valve counter-
clockwise to fully open the valve.
• Loosen the charge hose connected to the gas
side service port slightly to release the pressure,
then remove the hose.
• Replace the flare nut and its bonnet on the gas
side service port and fasten the flare nut securely
with an adjustable wrench. This process is very
important to prevent leakage from the system.
• Replace the valve caps at both gas and liquid
side service valves and fasten them tight.
This completes air purging with a vacuum pump.
The air conditioner is now ready to test run.
(1) Remove the caps from the gas side and liquid side
valves.
(2) Remove the service-port cap from the gas side
valve.
(3) To open the gas side valve turn the valve stem
counterclockwise approximately 90°, wait for about
2~3 seconds, and close it.
(4) Apply a soap water or a liquid neutral detergent on
the indoor unit connection or outdoor unit connec-
tions by a soft brush to check for leakage of the con-
necting points of the piping.
(5) If bubbles come out, the pipes have leakage.
Soap water method
Suction Line
Evaporator Line
Cap
Hexagonal wrench
3-way valve
(Open)
3-way valve
(Close)
Required time for evacuation when 30 gal/h vac-
uum pump is used
10 min. or more 15 min. or more
If tubing length is less
than 10m (33 ft)
if tubing length is longer
than 10m (33 ft)
Indoor unit
Outdoor unit
Lo Hi
Manifold valve
Vacuum pump
Pressure
gauge
Open Close