Fig. 9.3
Page 20
Air Evacuation
9
Safety Precautions
Evacuation Instructions
Before using the manifold gauge or vacuum
pump, read their operation manuals to familiarize
yourself with how to use them properly.
Manifold gauge
Compound gauge
-76 cmHg
Low-pressure valve
High-pressure valve
Charge hose
Charge hose
Vacuum pump
Pressure gauge
Low-pressure valve
Fig. 9.1
1. Connect the charge hose of the manifold
gauge to the 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 low-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 -76 cmHG (-1x105 Pa).
6. Close the low-pressure side of the manifold
gauge and turn off the vacuum pump.
7. Wait 5 minutes, then check that there has
been no change in the system pressure.
NOTE:
If there is no change in the system pressure,
unscrew the cap from the packed valve (high-
pressure valve). If there is a change in the system
pressure, there may be a gas leak.
8. Insert a hexagonal wrench into the packed valve
(high-pressure valve) and open the valve by
turning the wrench counterclockwise a 1/4 turn.
Listen for gas to exit the system, then
close the valve after 5 seconds.
Flare nut
Cap
Valve body Valve stem
Fig. 9.2
9. 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.
10.Remove the charge hose from the service port.
11. Using a hexagonal wrench, fully open both the
high-pressure and high-pressure valves.
OPEN
VAL
VE STEMS GENT
L
Y
When opening valve stems, turn the hexagonal
wrench until it hits against the stopper.
DO NOT
try to force the valve to open further.
12.Tighten the valve caps by hand, then tighten
them using the proper tool.
13.If the outdoor unit uses all vacuum valves,
and the vacuum position is at the main
valve, the system is not connected with the
indoor unit and must be tightened with a
screw nut. Check the gas leakage before
operation to prevent leakage.
Air
Evacuation
CAUTION
•
Use a vacuum pump with a gauge reading
lower than -0.1 MPa and an air discharge
capacity above 40 L/min.
•
The outdoor unit does not need vacuuming.
DO NOT
open the outdoor unit’s gas and
liquid stop valves.
•
Ensure that the compound meter reads
-0.1 MPa or below after 2 hours. If after 3
hours of operation the gauge reading is
still above -0.1 MPa, check if there is a gas leak
or water inside the pipe. If there is no leakage,
perform another evacuation for 1 or 2 hours.
•
DO NOT
use refrigerant gas to evacuate the
system.
