When the compressor operates, small amount of oil will be pumped out with the compressed vapor. A small amount of oil throughout the system does no harm. However, too much oil in such parts as the condenser, refrigerant flow controls, evaporator and filter interferes with their operation.
OIL SEPARATOR (by danfoss)
Source:
" Modern Refrigeration and air conditioning " by Andrew D. Carl. H, Alfred F.
