MCAC-VTSM-2015-09      R410A All DC Inverter V4+S Series 60Hz 
Troubleshooting 161 
Attached table 3: Commissioning and operating parameters of refrigerant system 
Condition 1: Make sure outdoor unit can detect all indoor units, the quantity of indoor units is displayed steadily and is equal to 
actual quantity of installed indoor units. 
Condition 2: Make sure all the valves in outdoor units are open, indoor units EXVs are connected to indoor PCB. 
Condition 3: The ratio of connectable indoor units is 100%. When ambient temperature is high, operate the system in cooling 
mode and set the temperature 17
o
C(62.6
o
F). When ambient temperature is low, operate the system in heating mode and set the 
temperature 30
 o
C(86
o
F). Then check the parameters after system has been running normally more than 30 minutes. 
Outdoor unit cooling parameters table   
Discharge pressure (spot check) 
Pressure of high pressure valve   
Pressure of low pressure valve 
Discharge temperature (spot check)   
DC inverter compressor current   
(BP1/BP2) (spot check)   
Average temperature of   
evaporator outlet T2B   
Outdoor unit heating parameters table   
Discharge pressure (spot check) 
Pressure of high pressure valve   
Pressure of low pressure valve 
Discharge temperature (spot check)   
DC inverter compressor current 
(BP1/BP2)*    (spot check)   
Average temperature of   
condenser outlet T2