LG THERMA V Installation Manual page 78

PIPING AND WIRING FOR OUTDOOR UNIT
78
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 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
0.8 torr or less
- When the desired vacuum is reached, close
the "Lo and Hi" 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.
If tubing length is
longer than 10 m(33 ft)
60 min. or more
Indoor unit
Outdoor unit
Manifold valve
Pressure
Lo Hi
gauge
Open Open
Vacuum pump