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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
Manifold Gauge
Compound
gauge
-76cmHg
Low pressure
valve
High pressure
valve
Pressure hose /
Charge hose
Charge hose
V
acuum
pump
Pressure gauge
Low pressure valve
1.
Connect the charge hose of the manifold
gauge to service port on the outdoor unit’s
low pressure valve.
Connect another charge hose from the
manifold gauge to the vacuum pump.
Open the Low Pressure side of the manifold
gauge. Keep the High Pressure side closed.
Turn on the vacuum pump to evacuate the
system.
Run the vacuum for at least 15 minutes, or
until the Compound Meter reads -76cmHG
(-10 Pa).
2.
3.
4.
5.
5
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 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).
9.
Insert hexagonal wrench into the packed valve
(high 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.
10.
Watch the Pressure Gauge for one minute
to make sure that there is no change in
pressure. The Pressure Gauge should read
slightly higher than atmospheric pressure.
Flare nut
Cap
valve body
valve stem
11.
Remove the charge hose from the service port.
12.
Using hexagonal wrench, fully open both the
high pressure and low pressure valves.
13.
Tighten valve caps on all three valves (service
port, high pressure, low pressure) by hand.
You may tighten it further using a torque
wrench if needed.
OPEN VALVE STEMS GENTLY
When opening valve stems, turn the hexagonal
wrench until it hits against the stopper. Do not
try to force the valve to open further.
Air Evacuation
