■
Evacuation
1. Connect the charge hose end described in the pre-
ceding 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 varied with the
tubing length and capacity of the pump. The follow-
ing table shows the amount of time for evacuation.
Allow the pump to operate until the system has
been evacuated down to 300 microns. Allow the
pump to continue running for an additional 15 min-
utes. Turn off the pump and leave the connections
secured to the two service valves. After 5 minutes,
if the system fails to hold 500 microns or less,
check all connections for tight fit and repeat the
evacuation procedure.
2. When the desired vacuum is reached, close the
"Lo" knob of the manifold valve and stop the vacu-
um 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 impor-
tant to prevent gas leakage from the system.
5. Replace the vlave caps at both gas and liquid side
service valves and fasten them securely tight.
This complete air purging with a vacuum pump. The air
conditoner is now ready to test run.
- 36 -
Indoor unit
Outdoor unit
Lo
Hi
Manifold valve
Vacuum pump
Pressure
gauge
Open
Close
