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12.5.9  Proper Pump Down Method 
 
1  Operate air conditioner 
at cooling mode for 
10~15 minutes.
 
2  After 10~15 minutes of pre operation, 
close 2 way valve. After 3 minutes, 
close 3 way valve. 
3  Take out air conditioner 
unit. 
4  Install New Refrigerant air 
conditioner. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Most Important Process
Purpose: To make the oil
& refrigerant mix together.
They are in separated
condition when
air conditioner
is stopped.
Mixed refrigerant & oil
will be collected into
outdoor unit.
Only very small
amount of oil remain
inside piping, which
is acceptable.