GMV5 D.C INVERTER MULTI VRF                                                                                              SERVICE MANUAL 
133 
 
01: 
The system does not set any master 
unit, and a master unit should be set. 
The system sets more than two master 
units, and a master unit should be set 
again. 
The system successfully sets a master 
unit and automatically enters the next 
step. 
According to the above fault symptoms, set the master unit again by referring to the setting method 
in  the  "Master  Unit  Setting  DIP  Switch  (SA8_MASTER-S)"  section.  Then  enter  unit  commissioning 
again. 
Exception 2: If no master IDU is detected in step 02, the following faults are displayed in step 02: 
In  this  case,  all  buttons  are  invalid.  Users  can  set  the  master  IDU  through  the  commissioning 
software, wired controller, or commissioning remote controller within one minute. If no master IDU is set 
within one minute, the system will automatically set a master IDU. Then the system automatically enters 
the next step. 
Step 7: When the unit runs to step 03, users need to manually confirm  the number  of  outdoor 
modules. The main board of each module is displayed as follows: 
03_Module quantity confirmation 
 
If the displayed quantity is consistent with the number of actually connected modules, press "SW7" 
on the master unit to confirm. The main board is displayed as follows and the unit automatically enters 
commissioning step 04. 
03_Module quantity confirmation 
If  the  displayed  quantity  is  inconsistent  with  the  number  of  actually  connected  modules,  check 
whether  communication cables  are  correctly  connected  between modules  in  power-off  status. Then 
perform commissioning again.