LG 3828A30087S Installation Manual page 28

Installation
Soap water method
(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 connections by a soft brush to
check for leakage of the connecting points
of the piping.
(5) If bubbles come out, the pipes have
leakage.
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
tubing length and capacity of the pump. The
following table shows the time required for
evacuation.
Required time for evacuation when 30 gal/h
vacuum pump is used
If tubing length is less
than 10m (33 ft)
10 min. or more
• When the desired vacuum is reached, close the
"Lo" knob of the manifold valve and stop the
vacuum 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.
28 Room Air Conditioner
if tubing length is longer
than 10m (33 ft)
15 min. or more
3-way valve
(Close)
3-way valve
(Open)
Manifold valve
Pressure
gauge
Open
Vacuum pump
Suction Line
Evaporator Line
Hexagonal wrench
Indoor unit
Outdoor unit
Lo Hi
Close
Cap