LG B42AWYU362 Installation Manual page 23

Soap water method
1. Remove the caps from 3-way valves.
2. Remove the service-port cap from the 3-way valve.
3. To open the liquid side 3-way valve turn the valve
stem counterclockwise approximately 90°, wait for
about 2~3 sec, 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
1. Connect the charge hose end described in the
preceding steps to the vacuum pump to evacuate
the tubing and indoor unit.
Confirm the "Lo and Hi" 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 10 m(33 ft)
30 min. or more
0.5 torr or less
2. When the desired vacuum is reached, close the "Lo
and Hi" knob of the manifold valve and stop the
vacuum pump.
Finishing the job
1. With a service valve wrench, turn the valve stem of
liquid side valve counter-clockwise to fully open the
valve.
2. Turn the valve stem of gas side valve counter-
clockwise to fully open the valve.
3. Loosen the charge hose connected to the gas side
service port slightly to release the pressure, then
remove the hose.
4. 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.
5. 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.
If tubing length is longer
than 10 m(33 ft)
60 min. or more
Air Purging and Evacuation
Outdoor unit
Gas side
3-way valve
(Close)
Liquid side
3-way valve
(Open)
Manifold valve
Lo
Open
Vacuum pump
Installation Manual 23
Gas side
piping
Liquid side
piping
Indoor unit
Outdoor unit
Digital vacuum
Hi
gage
Open