Which statement describes the function of an oil separator in a refrigeration system?

Which statement describes the function of an oil separator in a refrigeration system?

• A. They store liquid refrigerant.
• B. They guide refrigerant to the compressor.
• C. They separate oil from refrigerant and return oil to the compressor.
• D. They filter moisture from the refrigerant.

Answer: (C)

Oil must be recycled back to the compressor to keep the compressor properly lubricated and to prevent oil from circulating through the rest of the system. An oil separator does exactly that: it removes entrained oil from the refrigerant vapor coming from the compressor and channels the oil back to the compressor crankcase while allowing the refrigerant vapor to continue on to the condenser. This is why the statement describing separating oil from refrigerant and returning the oil to the compressor is the correct choice. The other ideas—storing liquid refrigerant, guiding refrigerant to the compressor, or filtering moisture—are handled by other components (receivers for storage, piping arrangements for flow routing, and dryers/dehydrators for moisture removal), not by the oil separator.

Oil must be recycled back to the compressor to keep the compressor properly lubricated and to prevent oil from circulating through the rest of the system. An oil separator does exactly that: it removes entrained oil from the refrigerant vapor coming from the compressor and channels the oil back to the compressor crankcase while allowing the refrigerant vapor to continue on to the condenser.

This is why the statement describing separating oil from refrigerant and returning the oil to the compressor is the correct choice. The other ideas—storing liquid refrigerant, guiding refrigerant to the compressor, or filtering moisture—are handled by other components (receivers for storage, piping arrangements for flow routing, and dryers/dehydrators for moisture removal), not by the oil separator.