The additional refrigerant charge is required according to the total 
piping length. Refer to Table 8.1.
After  vacuum  pumping  work,  check  that  the  high/low  pressure 
gas valve, low pressure gas valve (low pressure gas valve is for 
heat recovery system only) and liquid stop valve are fully closed. 
Charge  the  additional  refrigerant  from  the  check  joint  of  liquid 
stop valve (acceptable error must be within 0.5 kg).
After the refrigerant has been charged, fully open the liquid stop 
valve and the gas stop valves.
  NOTE
The gas staying at O-ring or screw part may make sound when 
removing the cap of the spindle. However, it is not gas leakage.
If it is impossible to charge the specied quantity of refrigerant, 
follow the procedure below: 
a.  Fully  open  the  stop  valve  for  the  gas  line.  (For  heat 
recovery  system,  both  stop  valves  of  high/low  pressure 
and low pressure side).
  CAUTION
Do not apply an excessive force to the spindle valve after fully 
opening the spindle. Otherwise, the spindle valve ies out due to 
refrigerant pressure. At the test run, open fully the spindle valve, 
otherwise, the devices will be damaged. (It is closed before ship-
ment).
Caution for opening stop valve
1  Do not apply an excessive force after fully opening the spin-
dle. (Tightening Torque: < 5.0N-m). (The back seat is not pro-
vided.)
2  When the valve is opened, remove the tags “Close” (Acces-
sories) and attach the tags “Open” (Accessories) instead.
3  Tighten securely the caps according to the tightening torque 
(Item 8.1-(2)-(e)) after each spindle valve is opened.
Check joint
(Only the charging hose for 
R410A can be connected.)
Cap
Counterclockwise...Open 
Clockwise...............Close
Refrigerant 
pressure
Spindle valve
Hexagonal wrench
High/Low Pressure 
  Low Pressure : 10mm 
       Liquid : 4mm
O-ring 
(Rubber)
(To open or close spindle valve)
Closed before shipment
b.  Operate the compressor in the cooling mode and charge 
the additional refrigerant from the check joint of the liquid 
stop valve (acceptable error must be within 0.5 kg). At this 
time, keep the liquid stop valve slightly opened 
c.  After the refrigerant is charged, fully open the liquid stop 
valve and the gas stop valve.
d.  Calculate  securely  the  additional  refrigerant  quantity  for 
charging. If the quantity of additional refrigerant is not cor-
rect, it may cause compressor failure. The additional re-
frigerant must be charged in a liquid condition.
e.  Refrigerant charge from check joint of gas stop valve may 
lead to compressor failure. Be sure to charge refrigerant 
from the check joint of liquid stop valve.
9.4  CHARGING WORK
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PMML0294A rev.2 - 07/2014
Additional refrigerant charge
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