ESCO Air Conditioning Practice Exam 2025 – The All-in-One Guide to Exam Success!

The oil separator is installed in the discharge line of an air conditioning system. Its primary function is to separate oil from the refrigerant as it exits the compressor, ensuring that only the refrigerant moves on to the condenser. When refrigerants are compressed, oil can get carried along in the refrigerant stream due to the high pressures and temperatures involved.

By placing the oil separator in the discharge line, it allows for a more efficient system by returning the separated oil back to the compressor. This is crucial for maintaining proper lubrication of the compressor components and ensuring that they do not run dry, which could lead to wear and premature failure.

The other placement options do not achieve the same separation function effectively. For example, placing the separator before the metering device would not allow for the effective capture of oil that is primarily carried in the compressor discharge. Similarly, an oil separator located on the incoming air side of the condenser or in the suction line would not serve the same purpose and could introduce operational issues, as these areas are not designed for oil separation.