D.C. Inverter Multi VRF Modular 
 
50 
No error in outdoor components. Start 
next progress. 
07_Detect indoor 
components 
System detects error in indoor 
components. XXXX is the project no. of 
the faulted IDU. 3s later, relevant error 
code is displayed. For example, IDU no. 
100 has d5 error, then LED3 displays like 
this: 01 (2s later) 00 (2s later) d5, and 
repeat again. 
No error in indoor components. Start 
next progress. 
08_Confirm 
preheated 
compressor 
Preheat time for compressor is less than 
8h. 
Preheat time for compressor is 8h. Start 
next progress. 
09_Refrigerant 
judgments 
before startup 
System refrigerant is not enough. 
System downtime equilibrium pressure is 
lower than 0.3MPa.   
System refrigerant is normal. Start next 
progress. 
10_Status 
judgments of 
outdoor valves 
before startup 
Outdoor valves are being turned on. 
Outdoor valves are not fully turned on. 
Outdoor valves are turned on normally. 
Description of each stage of debugging progress 
11_Calculate 
refrigerant 
quantity 
manually 
Calculate the refrigerant quantity 
manually and confirm the perfusion 
status of refrigerant (the quantity of 
refrigerant added into the system must 
be recorded accurately). 
12_Confirm 
debugging 
startup 
Ready for units to start debugging. 
Manual calculation of refrigerant quantity 
is set up. 
Debugging is enabled in cooling mode 
(debugging mode, auto-selected by 
system).   
Error occurs during debugging in cooling 
mode. 
Error of other modules occurs during 
debugging in cooling mode.