LG UUA1 Montageanleitung Seite 29

1
Do a leakage test of all joints of the tubing
(both Indoor unit and outdoor unit) and
both gas and liquid side service valves.
Bubbles indicate a leak. Be sure to wipe
off the soap with a clean cloth.
2
After the system is found to be free of
leaks, relieve the nitrogen pressure by
loosening the charge hose connector at
the nitrogen cylinder. When the system
pressure is reduced to normal, disconnect
the hose from the cylinder.
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.
- 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.
LEAKAGE TEST AND EVACUATION
Outdoor unit
Manifold valve
Lo
Required time for evacuation when 11.36 l/h
vacuum pump is used
If tubing length is less
than 10 m (33 ft)
30 min. or more
0.07 kPa or less
Outdoor unit
Manifold valve
Lo
Open
Vacuum pump
29
Indoor unit
Pressure
gauge
Hi
Charge hose
Nitrogen gas
cylinder (in vertical
standing position)
If tubing length is
longer than 10 m (33 ft)
60 min. or more
Indoor unit
Pressure
gauge
Hi
Open