LG THERMA V AHNW16606B0, Installation Manual, Page: 58 / 65

58 Air-to-Water Heat Pump
Piping and Wiring for Outdoor Unit
Evacuation
1. Connect the charge hose end described in the
preceding steps to the vacuum pump to evacuate
the tubing and indoor unit.
Confirm that 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.
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 it tightly.
This completes air purging with a vacuum pump.
The air conditioner is now ready to test run.
Outdoor unit
Lo Hi
Manifold valve
Vacuum pump
Open Open
Pressure
gauge
Indoor unit
Required time for evacuation when 30 gal/h
vacuum pump is used
30 min. or more 60 min. or more
0.5 torr or less
If tubing length is less
than 10 m(33 ft)
If tubing length is longer
than 10 m(33 ft)