Air Evacuation
Preparations and Precautions
Air and foreign matter in the refrigerant circuit can
cause abnormal rises in pressure, which can damage
the air conditioner, reduce its efficiency, and cause
injury. Use a vacuum pump and manifold gauge to
evacuate the refrigerant circuit, removing any non-
condensable gas and moisture from the system.
Evacuation should be performed upon initial installation
and when unit is relocated.
BEFORE PERFORMING EVACUATION
Check to make sure the connective pipes between
the indoor and outdoor units are connected
properly.
Check to make sure all wiring is connected
properly.
Evacuation Instructions
1. Connect the charge hose of the manifold gauge
to service port on the outdoor unit's low pressure
valve.
2. Connect another charge hose from the manifold
gauge to the vacuum pump.
3. Open the Low Pressure side of the manifold gauge.
Keep the High Pressure side closed.
4. Turn on the vacuum pump to evacuate the system.
5. Run the vacuum for at least 15 minutes, or until the
Compound Meter reads -76cmHG (-10
Manifold Gauge
Compound gauge
-76cmHg
Low pressure valve
Pressure hose/
Charge hose
Low pressure valve
6. Close the Low Pressure side of the manifold gauge,
and turn off the vacuum pump.
7. Wait for 5 minutes, then check that there has been
no change in system pressure.
8. If there is a change in system pressure, refer to Gas
9. Insert hexagonal wrench into the packed valve (high
10. Watch the Pressure Gauge for one minute to make
11. Remove the charge hose from the service port.
12. Using hexagonal wrench, fully open both the high
13. Tighten valve caps on all three valves (service port,
5
Pa).
When opening valve stems, turn the hexagonal
Pressure gauge
wrench until it hits against the stopper. Do not try to
force the valve to open further.
High pressure valve
Charge hose
Vacuum pump
Leak Check section for information on how to check
for leaks. If there is no change in system pressure,
unscrew the cap from the packed valve (high
pressure valve).
pressure valve) and open the valve by turning the
wrench in a 1/4 counterclockwise turn. Listen for
gas to exit the system, then close the valve after 5
seconds.
sure that there is no change in pressure. The
Pressure Gauge should read slightly higher than
atmospheric pressure.
Flare nut
valve body
valve stem
pressure and low pressure valves.
high pressure, low pressure) by hand. You may
tighten it further using a torque wrench if needed.
OPEN VALVE STEMS GENTLY
Cap
Page 21-GB