13 
 
4.5  Adding  Refrigerant  after  Long-Term 
System Operation 
 
Procedure 
1)  Connect  the  charge  hose  to  the  3-way  service 
port and open the 2-way and 3-way valve. 
Connect the charge hose to the valve at the 
bottom of the cylinder. If the refrigerant is R410A, 
place the cylinder bottom-up to ensure liquid 
charge. 
2). Purge the air from the charge hose. 
Open the valve at the bottom of the cylinder and 
press the check valve on the charge set to purge 
the air (be careful of the liquid refrigerant). 
3) Place the charging cylinder onto the electronic 
scale and record the weight. 
4) Turn on the air conditioner in cooling mode. 
5) Open the valves (Low side)on the charge set and 
charge the system with liquid refrigerant. 
6).When  the  electronic  scale  displays  the  proper 
weight (refer  to the  gauge and  the pressure  of the 
low  side),  disconnect  the  charge  hose  from  the  3-
way  valve’s  service  port  immediately  and  turn  off 
the air conditioner before disconnecting the hose. 
7). Mount the valve stem caps and the service port. 
Use torque wrench to tighten the service port cap 
to a torque of 18N.m(13.27 ft·lbs). 
Be sure to check for gas leaks. 
4.6  Procedure  when  servicing  the  indoor 
unit refrigeration circuit. 
1.  Collecting the refrigerant into the outdoor 
unit 
 
Procedure 
1).  Confirm  that  both  the  2-way  and  3-way  valves 
are set to the opened position 
Remove  the  valve  stem  caps  and  confirm  that  the 
valve stems are in the opened position. 
Be sure to  use  a hexagonal wrench to operate the 
valve stems. 
2).  Connect  the  charge  hose  with  the  push  pin  of 
handle lo to the 3-way valves gas service port. 
3). Air purging of the charge hose. 
Open  the  handle  Lo  valve  of  the  manifold  valve 
slightly  to  purge  air  from  the  charge  hose  for  5 
seconds and then close it quickly. 
4). Set t  e 2-way valve to the close position. 
5).  Operate  the  air  conditioner at  the  cooling  cycle 
and stop it when the gauge indicates 0.1MPa. 
6).  Set  the  3-way  valve  to  the  closed  position 
immediately 
Do this quickly so that the gauge ends up indicating 
0.3 to 0.5Mpa. 
Disconnect  the  charge  set,  and  tighten  the  2-way 
and 3-way valve’s stem nuts.  
Use  a  torque  wrench  to  tighten  the  3-way  valves 
service port cap to a torque of 18N.m. 
Be sure to check for gas leakage. 
 
2. Air purging with vacuum pump