New Jersey Blue Seal Refrigeration Practice Exam

Running a reciprocating compressor with the suction valve closed and the discharge valve open creates a situation where the compressor is running against a vacuum. In this scenario, the compressor will not be able to draw any refrigerant gas into the cylinder since the suction valve is closed. However, because the discharge valve is open, the compressor will struggle to expel any refrigerant, which could allow for the ingress of non-condensables, such as air or moisture, into the system.

This condition can lead to several problems. Non-condensables can cause inefficiencies in the refrigeration cycle, increase discharge pressure, and can potentially lead to compressor damage over time due to the presence of air and moisture. It may also result in excessive wear on the internal components of the compressor and could affect the overall performance of the refrigeration system.

The other outcomes suggested in the choices do not accurately reflect the consequences of closing the suction valve while keeping the discharge valve open. The compressor cannot operate efficiently because it is not cycling the refrigerant properly, continuously flowing refrigerant is impossible without a functioning suction side, and the system cannot reach a low pressure because it is not sealed off correctly from the suction side.