Fig. 7.1
Compound gauge
-76cmHg
High pressure valve
Pressure hose /
Charge hose
Charge hose
Vacuum pump
Pressure gauge
Low pressure valve
Low pressure valve
Max.
Max.
7.1 Preparations and Precautions
7.2 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. Tur
n on the vacuum pump to evacuate the system.
5. Run the vacuum for at least 15 minutes, or until the Compound Meter
r
eads -76cmHG (-10
5
Pa).
6. Close the Low P
ressure side of the manifold gauge, and turn of
f the vacuum pump.
7.
W
ait for 5 minutes, then check that there has been no change in system pressure.
8. If there is a change in system pressure, r
efer to Gas Leak Check section for information on how to check for leaks. If
there is no change in system pressure, unscrew the cap fr
om the packed valve (high p
ressur
e valve).
9. Insert hexagonal wrench into the packed
v
a
lv
e (high pressure
v
a
lv
e) and open the
v
a
lv
e by turning the wrench in a 1/4
counterclockwise tur
n. Listen for gas to exit the system, then close the valve after 5 seconds.
10.
W
atch the Pressur
e Gauge for one minute to make su
re that there is no change in pressure. The Pressur
e Gauge
should read slightly higher than atmospheric pressure.
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.
7. Air Evacuation
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 using the manifold gauge and vacuum pump, read their operation manuals to familiarize yourself with
how to use them properly.
Before Performing evacuation
1. Check to make sure that both high-pressure and low-pressure pipes between the indoor and outdoor units
are connected properly in accordance with the Refrigerant Piping Connection section of this manual.
2. Check to make sure all wiring is connected properly.
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