Evacuation - LG A7UW40GFA0 Installation Manual

AIR PURGING AND EVACUATION
28
WARNING
!
Use a vacuum pump or Inert (nitrogen)
gas when doing leakage test or air purge.
Do not compress air or Oxygen and do
not use Flammable gases. Otherwise, it
may cause fire or explosion.
- There is the risk of death, injury, fire or
explosion.

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
10 m (33 ft)
Less than 0.5 Torr
- 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.
If tubing length is
longer than
10 m (33 ft)
Less than 0.5 Torr
- 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.
Indoor unit
Outdoor unit
Manifold valve
Pressure
Lo Hi
gauge
Open
Open
Vacuum pump