Refrigeration and Compressor Systems Quiz

A refrigeration system operates at a suction pressure of 45 psig using R-134a. What is the approximate evaporator temperature?

• 20°F

• 25°F

• 30°F

• All of the above

A compressor is drawing 18.5A at 240V with a power factor of 0.85. What is the real power consumption in kilowatts? (P = V x I x PF / 1,000)

• 3.5 kW

• 4.5 kW

• 5.0 kW

• All of the above

A refrigeration system with a TXV is experiencing low suction pressure and high superheat. What is the most likely issue?

• A restricted TXV

• An undercharged system

• A clogged liquid line filter-drier

• All of the above

A refrigeration compressor has a volumetric efficiency of 85% and a displacement of 50 CFM. What is the actual refrigerant flow rate?

• 40 CFM

• 42.5 CFM

• 45 CFM

• All of the above

A refrigeration system has a liquid line temperature of 90°F and a saturation temperature of 110°F at the measured pressure. What is the subcooling value?

• 10°F

• 15°F

• 20°F

• All of the above

A refrigeration system has a total cooling capacity of 36,000 BTU/hr and a power input of 3.5 kW. What is the system's EER (Energy Efficiency Ratio)? (EER = BTU/hr ÷ kW)

• 8.5

• 9.2

• 10.3

• All of the above

A system has a superheat reading of 20°F. What does this indicate?

• The TXV is underfeeding

• The system is low on refrigerant

• The evaporator is starved

• All of the above

A heat pump in cooling mode has an indoor coil pressure of 125 psig using R-410A. What is the approximate evaporator saturation temperature?

• 42°F

• 47°F

• 52°F

• All of the above

A system has an evaporator pressure of 55 psig and a condenser pressure of 250 psig using R-22. What is the approximate compression ratio?

• 3.8:1

• 4.5:1

• 5.2:1

• All of the above

What is a possible cause of compressor valve failure?

• Compressor valve failure

• Restricted airflow

• All of the above

• None of the above