R410A All DC Inverter V4+S Series 60Hz      MCAC-VTSM-2015-09 
4      General Information 
1.3 High reliability 
1.3.1 Cycle duty operation   
The cyclical start-up sequence of outdoor units and DC inverter compressors equalized compressor duty and 
extends operating life 
.   
1.3.2 Back-up function 
In a multiple system, if one module is failed, other modules can be backup instead of the failed one for 
continuing operation. 
 
1.3.3 Precise oil control technology 
5 stages oil control technology ensures all outdoor unit and compressor oil is always kept at a safe level, 
completely solving any compressor oil shortage problems. 
  1st stage: Compressor internal oil separation. 
  2nd  stage:  High  efficiency  centrifugal  oil  separator  (separation  efficiency  up  to  99%)  ensures  oil 
separated from the discharge gas is returned to the compressors. 
  3rd stage: Oil  balance  pipes  between  compressors ensure even oil distribution to keep compressors 
running normally. 
  4th stage: Oil balance pipes among modules ensure even oil distribution among modules. 
  5th stage: Auto oil return program by monitoring the running time and system status ensures reliable oil 
return.