Which statement describes the parameters included in a baseline performance check?

• A. Suction Pressure, Discharge Pressure, and Discharge Line Temperature
• B. Only Suction Pressure
• C. Only Discharge Line Temperature
• D. Suction Pressure and Discharge Pressure (but not Temperature)

Answer: (A)

In a baseline performance check, you want a reference snapshot of the system’s operating conditions so you can spot changes over time. Recording suction pressure tells you how the evaporator is performing and how the refrigerant is expanding at the low side. Recording discharge pressure shows the compressor’s load and how well the condenser is rejecting heat. Recording the discharge line temperature adds a critical thermal reading of the gas right after compression, which relates to compression efficiency and potential overheating or abnormal wear. Taken together, these three measurements give a complete picture of how the system starts up and runs, so you can compare future checks to this baseline and identify components that drift out of spec or begin to fail. Omitting any one of these parameters would leave a gap in understanding the overall performance, so the option that includes all three is the best choice.