-39-
2. Pumping down
• Procedure
(1) Confirm that both the 2-way and 3-way valves
are set to the open position.
– Remove the valve stem caps and confirm that
the valve stems are in the raised position.
– Be sure to use a hexagonal wrench to operate
the valve stems.
(2) Operate the unit for 10 to 15 minutes.
(3) Stop operation and wait for 3 minutes, then
connect the charge set to the service port of
the 3-way valve.
– Connect the charge hose with the push pin to
the service port.
(4) Air purging of the charge hose.
– Open the low-pressure valve on the charge set
slightly to air purge from the charge hose.
– Refrigerant must be recovered.
Don’t vent the Refrigerant in the atmosphere.
(5) Set the 2-way valve to the closed position.
(6) Operate the air conditioner at the cooling
cycle and stop it when the gauge indicates
1kg/cm
2
g.
(7) Immediately set the 3-way valve to the closed
position.
– Do this quickly so that the gauge ends up
indicating 3 to 5kg/cm
2
g.
(8) Disconnect the charge set, and mount the 2-
way and 3-way valve’s stem nuts and the
service port nut.
– Use torque wrench to tighten the service port
nut to a torque of 1.8 kg.m.
– Be sure to check for gas leakage.
Lo
Closed
Purge the air
Outdoor unit
Indoor unit
Liquid side
Gas side
CLOSE
Open
2-Way
valve
3-Way
valve
CLOSE
CAUTION
Do not use the existing charge set for R-22.
It is necessary to use new charge set for R-410A.
The pressure of R-410A is 1.6 times higher than
that of R-22. Thus, the high pressure side gauge
of charge set should be used higher pressure
gauge of 50kg/cm
2
range.
