VC Pro VRF 50/60Hz       
44     
Midea VC Pro Series Engineering Data Book 
Key components: 
1.  Oil separator:   
Separates oil from gas refrigerant pumped out of the compressor and quickly returns it to the compressor. Separation 
efficiency is up to 99%. 
2.  Accumulator:   
Stores liquid refrigerant to protect compressor from liquid hammering. 
3.  Electronic expansion valve (EXV): 
Controls refrigerant flow and reduces refrigerant pressure. 
4.  Solenoid valve SV2:   
Protects the compressor. If compressor discharge temperature rises above 100
o
C, SV2 opens and sprays a small amount 
of liquid refrigerant to cool the compressor. SV2 closes again once the discharge temperature has fallen below 90
o
C. 
5.  Solenoid valve SV4:   
Returns oil to the compressor. Opens once the compressor has run for 200 seconds and closes 600 seconds later and 
then opens for 3 minutes every 20 minutes. 
6.  Solenoid valve SV7: 
Allows  refrigerant  to  return  directly  to  the  compressor.  Opens  when  indoor  air  temperature  is  close  to  the  set 
temperature to avoid frequent compressor on/off. Opens when superheat degree is insufficient to avoid liquid hammer 
to compressor. 
7.  low pressure switches:   
Regulate  system  pressure.  When  system  pressure  falls  below  the  lower  limit,  the  low  pressure  switches  turn  off, 
stopping the compressor. After 10 minutes, the compressor restarts.