AERMEC MGH R410A Manuel D'installation page 18

3. 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
10m (33 ft)
10 min. or more
When the desired vacuum is reached, close
the "Lo" knob of the manifold valve and stop
the vacuum pump.
CAUTION
Use vacuum pump equipped with check valve
applied to be prevented from flowing backward.
4. 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 10m (33 ft)
15 min. or more
15
Outdoor unit
3-way valve
(Close)
2-way valve
(Open)
3-way valve
(Close)
2-way valve
(Open)
Hexagonal wrench
Outdoor unit
Manifold valve
Pressure
Lo Hi
gauge
Open
Vacuum pump
A-UNIT
Gas side piping
B-UNIT
Liquid side piping
Cap
Indoor unit
Close