GREE                                                                        GMV5E DC INVERTER VRF UNITS SERVICE MANUAL 
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Error judgment condition and method: 
During commissioning, check if ODU cut-off valve is opened through detecting system parameter by 
pressure sensor. If the parameter is abnormal, it will indicate that confirming the open of cut-off valve and 
then press SW5 to enter the next step after confirming. 
Possible reason: 
■ODU cut-off valve is not opened; 
Troubleshooting: 
Confirm again and open ODU cut-off valve. 
2.2.4.136 “U8” IDU pipeline error 
Error  display: 
ODU  mainboard,  IDU  wired  controller  and  IDU  receive  light  board  will 
display
 
Error judgment condition and method: 
During  commissioning,  check  if  IDU  pipeline  is  blocked  through  detecting  IDU  pipeline.  If  the 
parameter is abnormal, it will indicate t 
Possible reason: 
■Electronic expansion valve doesn’t operate normally; 
■IDU pipeline is blocked; 
Troubleshooting: 
 
2.2.4.137 “U9” ODU pipeline error 
Error  display: 
ODU  mainboard,  IDU  wired  controller  and  IDU  receive  light  board  will 
display
 
Error judgment condition and method: 
During commissioning, check if ODU pipeline is blocked through detecting system pressure. If the 
parameter is abnormal, it will indicate this error.