V6-i VRF 50/60Hz       
38     
Midea V6-i Series Service Manual
 
5 Normal Operation Control 
5.1 Component Control during Normal Operation 
Table 3-5.1: Component control during normal cooling operation 
Control functions and states 
Controlled according to load requirement 
Controlled according to discharge pressure 
Electronic  expansion 
valve A 
Position  (steps)  from 0  (fully closed)  to 480 
or 3000 (fully open), controlled according to 
discharge temperature 
Electronic  expansion 
valve C 
Position  (steps)  from 0  (fully closed)  to 480 
(fully  open),  controlled  according  to 
temperature  different  between  plate  heat 
exchanger inlet and outlet 
Solenoid  valve  (oil 
balance) 
Solenoid  valve  (fast 
defrosting  (in  cooling) 
and  unloading  (in 
heating)) 
Controlled  according  to  ambient 
temperature,  discharge  pressure,  discharge 
temperature,  compressor  running 
frequency and discharge superheat 
Solenoid  valve  (EXV 
bypass) 
Controlled  according  to  discharge  pressure 
and discharge temperature 
Solenoid  valve  (indoor 
units bypass) 
Controlled according to load requirement 
Solenoid  valve  (inverter 
compressor  A  vapor 
injection) 
Controlled according to inverter compressor 
A on/off 
Solenoid  valve  (inverter 
compressor  B  vapor 
injection) 
Controlled according to inverter compressor 
B on/off 
Solenoid  valve  (inverter 
compressor  B  pressure 
balance) 
Open before compressor B startup and close 
after compressor B running for  15  seconds. 
Open  after  compressor  B  stop  10  seconds 
and keep open 60 seconds.