LG UU21WH Installation Manual page 18

Leakage test and Evacuation
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.
18 Air Conditioner
If tubing length is longer
than 10 m(33 ft)
60 min. or more
Indoor unit
Outdoor unit
Manifold valve
Lo Hi
Open Open
Vacuum pump
Pressure
gauge