GMV DC Inverter VRF 
54 
Meaning   
Code 
Code   
Code 
01~04  ON  OF  ON  OF  ON 
The complete unit has conducted the 
debugging and the unit is under standby 
status. LED1 displays module address; LED2 
and LED3 displays “OF”.   
4.3 Basic Introduction for Engineering Debugging   
4.3.1 Debugging Method 
DC inverter multi VRF unit has three debugging methods at present: 
(1)  Conduct it by pressing the buttons on the main board of outdoor unit.   
(2)  Install proprietary software to conduct the debugging through PC. Indoor and outdoor units’ 
parameters displayed simultaneously through PC software. 
(3)  Use multi-functional debugger. 
Note:
  As for the detailed operation method for debugging, please refer to corresponding 
instruction manual.   
4.3.2 Debugging Through the Main Board of Outdoor Unit 
When conducting the debugging through the main board of outdoor unit, the main board has the 
following debugging operation functions.   
Step 1: Cover all the front panels of the outdoor unit and open the debugging window of each 
basic module. 
Step 2: When the outdoor unit is powered off, set one of the modules as the master module. For 
the setting method, see “Master Module DIP Switch Code Setting (SA8_MASTER-S)”. 
Step 3: Under the power-on state of the outdoor unit, set the corresponding static pressure module 
for the unit according to the design requirements of the outdoor static pressure of the project. 
Step 4: The module address is displayed as "01” is the master module. On the master module, 
press and hold the SW3 confirmation button for 5 seconds or press the SW3 confirmation button for 
more than 10 seconds to enter the unit debugging function. 
Step 5: Wait. The unit automatically runs the steps 01 and 02 at this time. 
If the master module is set incorrectly in step 01, the following corresponding fault is displayed in 
step 01: 
— 
Debugging 
Progress code  Status code 
Meaning   
Progress 
Code 
Display 
Code 
Display 
Code 
Display 
01_ set up 
master unit
db  ON  01  ON  CC  ON 
Mater module hasn’t been set in the system. It 
needs to reset it. 
db  ON  01  ON  CF  ON 
More than two master modules are set in the 
system and it needs to reset it. 
db  ON  01  ON  OC  ON 
Mater module of system has been set 
successfully. Enter into the next step 
 
According to the above fault phenomenon, reset the master module according to the setting 
method of “Master Module DIP Switch Code Setting (SA8_MASTER-S)”, and re-enter into the