Where is refrigerant added to a low pressure system during the refrigerant charging process?

• A. The top access point
• B. The compressor inlet
• C. The lowest access point on the system
• D. The service port

Answer: (C)

In a low-pressure refrigeration system, refrigerant is added at the lowest access point on the system. This procedure is crucial because it allows for the effective introduction of refrigerant into the system, where it can circulate and provide the desired cooling effect.

By adding refrigerant at the lowest point, you help ensure that any air or non-condensable gases, which tend to rise to the top of the system, are not inadvertently mixed with the refrigerant being added. This method also promotes better mixing of the refrigerant with the existing charge and aids in the detection and resolution of any potential leaks or issues within the system.

The other choices represent points in the system that may not be suitable or effective for refrigerant charging; for instance, the service port is specifically designed for diagnostic and gauge connections rather than for charging. The compressor inlet and the top access point may also introduce unwanted gas and result in inefficient charging practices. Thus, the correct choice emphasizes the importance of proper procedures in maintaining system efficiency and integrity.