Air Purging 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" 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 10m (33 ft)
Less than 0.5 Torr
2. When the desired vacuum is reached, close
the "Lo" 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 pres-
sure, 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 for test running.
NOTICE
: Repeat evacuation procedure for each
indoor unit.
42 Multi Air Conditioner
If tubing length is longer
than 10m (33 ft)
Less than 0.5 Torr
Indoor unit
Outdoor unit
h The figure can be changed according to model.
Manifold valve
Pressure
Lo
Hi
gauge
Open
Open
Vacuum pump