48 Room Air Conditioner
Troubleshooting Guide 
• 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. 
(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 indi-
cating 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 ser-
vice 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. 
Pumping Down 
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/cm2 range.