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1. Connection of gauge manifold
a) Remove the crushed end of the pinch-
off tube on the high pressure side of the
refrigerant cycle with a pipe cutter.
b) Connect the process tube fitting to the
pinch-off tube on both sides.
c) Connect the red charging hose of the gauge
manifold to the process tube fitting on the
high pressure side.
Note:
Red hose is for high pressure side and blue hose
(not shown) is for low pressure side.
d) Connect the charging hose (yellow) to the
center of the gauge manifold to the vacuum
pump.
2. Evacuation
a) Open the high pressure valve (Hl) of the
gauge manifold.
b) Turn on the vacuum pump to start
evacuation. It takes 15 minutes.
c) When the low pressure gauge indicates
30 inHg (100 kPa) or larger, turn off the
vacuum pump and close the high pressure
valves of the gauge manifold.
3. Checking
vacuum
a) Leave the high and low pressure valves of
the gauge manifold closed for 5 minutes or
more, and confirm that the gauge pointer
does not return to zero.
b) If the gauge pointer returns gradually to
zero, perform leak check according to the
procedure in the next step. After repairing
the leaks, evacuate the system once more
and check vacuum.
Pinch-Off Tube
Charging Hose
Side
Refrigerant
Cycle Side
Process Tube Fitting
High Pressure Valve
(Closed)
High Pressure
Side Tube
Vacuum Pump
Low Pressure
Valve (Closed)
Red Hose
Yellow Hose
Process Tube Fitting
LO
Closed
HI
Open
LO
Closed
HI
Closed
Valve Setting
30 inHg (100 kPa) or larger
High Pressure Valve
High Pressure Gauge
Gauge
High Pressure
Side Tube
Low Pressure
Valve
Return
Pipe Brazing
LO
Closed
HI
Closed
Valve Setting
Pressure Gauge
Charging the System with R-410A Refrigerant
