In semi-hermetic compressors, what is the primary function of the suction vapor?

The primary function of the suction vapor in semi-hermetic compressors is to cool the motor. This is essential because the motor generates heat during operation. The suction vapor, being at a low pressure and temperature, absorbs some of this heat, helping to maintain an optimal operating temperature for the motor. This cooling effect is crucial for the longevity and efficiency of the compressor, preventing overheating and potential damage.

In addition, while lubrication is vital for the operation of compressors, it is not the primary role of the suction vapor itself; rather, lubrication typically comes from the oil that may be mixed with the refrigerant. The suction vapor does not heat the refrigerant to facilitate compression; in fact, the refrigeration cycle relies on removing heat from the refrigerant as it passes through the evaporator. Therefore, while all options relate to compressor operation, the correct answer highlights the specific function of the suction vapor in thermally protecting the motor.