GMV DC Inverter VRF 
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5.2.2.2 Debugging operation mode 
GMV5E multi VRF system has two debugging modes: one is direct operation on main 
board of outdoor units while the other is PC operation via special software. In PC software 
debugging, indoor/outdoor parameters can be displayed and historical data can be recorded 
and inquired. (Operation details can be found in relevant instruction manuals) 
(1) Debugging through operation on main board of outdoor units 
In this debugging mode, following debugging functions are included on the main board: 
Step 1: 
front panel of the outdoor units must be fully closed. Open the debugging window 
of each basic module; 
Step 2:
 disconnect power for outdoor units. According to design requirements of external 
static pressure, set up corresponding static pressure mode for the units. Setting methods can 
be seen in Outdoor Fan Static Pressure Setup SA6_ESP_S; 
Step 3: 
disconnect power for outdoor units and set one module as a master unit. Setting 
methods can be seen in Master Unit Setup SA8_MASTER_S; 
Step 4: 
Connect power for all indoor units. Make sure all IDUs are power on. Then all 
outdoor modules will display “Debugging not enabled”; 
Step 5: 
Find the module with “01” module address to be the master module. Hold SW7 
button on the master module for at least 5s to enable debugging; 
Step 6: 
Wait. Unit will then start progress 01 and 02; in progress 01, if master unit is not 
correctly set, progress 01 will show the following errors: 
01_01 Set 
up master 
unit: 
System doesn’t have master unit. Reset 
master unit. 
More than 2 master units are set. Reset 
master unit.   
Master unit is successfully set. Start next 
progress. 
According to the above errors, reset the master unit as instructed in Master Unit Setup 
SA8_MASTER_S. After reset is finished, start debugging again. 
In progress 02, if master IDU is not detected, then progress 02 will show the following 
errors: 
At this time, all buttons are ineffective. Set master IDU in 1min via debugging software. If 
master IDU is not set in 1min, system will set up a master IDU randomly. After that, system will 
start next progress. 
Step 7: 
in progress 03, the quantity of modules needs to be confirmed manually. Main