V5 X VRF 50/60Hz 
201608    87 
Part 5 - Diagnosis and Troubleshooting 
 Procedure 4.17.4
 
ODU stop valves are closed 
Insufficient refrigerant caused by 
refrigerant leakage
1
 
Add refrigerant or inspect the system for 
leaks 
The low pressure side is blocked, caused 
by crushed or bent pipe, blocked EXV, or 
dirty filter
2
 
Inspect the system and fix the error. If the 
filter is blocked by ice, the piping should 
be cleaned 
The evaporator heat exchange is poor
5
 
Inspect the system and fix the error 
 
Notes:     
1.  To check for insufficient refrigerant: 
  Re-start the outdoor units. If an r1, r2 or r3 error is displayed upon start-up, there is insufficient refrigerant in the system. 
  An insufficiency of refrigerant causes compressor discharge temperature to be higher than normal, discharge and suction pressures to be lower than 
normal  and  compressor  current  to  be  lower  than  normal,  and  may  cause  frosting  to  occur  on  the  suction  pipe.  These  issues  disappear  once 
sufficient  refrigerant  has  been  charged  into  the  system.  For  normal  system  parameters  refer  to  Tables  5-5.4  and  5-5.5  in  Part  5,  5.2  “Normal 
Operating Parameters of Refrigerant System”. 
2.  A  low  pressure  side  blockage  causes  compressor  discharge  temperature  to  be  higher  than  normal,  suction  pressure  to  be  lower  than  normal  and 
compressor current to be lower than normal, and may cause frosting to occur on the suction pipe. For normal system parameters refer to Tables 5-5.4 and 
5-5.5 in Part 5, 5.2 “Normal Operating Parameters of Refrigerant System”. 
3.  In cooling mode check indoor heat exchangers, fans and air outlets for dirt/blockages. In heating mode check outdoor heat exchangers, fans and air outlets 
for dirt/blockages.