CT Refrigeration Contractor Exam
Questions and Correct Answers (Verified
Answers) Plus Rationale 2027 Q&A|
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1. What is the primary function of the compressor in a vapor-
compression refrigeration system?
A. To remove heat from the condenser
B. To lower the pressure of liquid refrigerant
C. To raise the pressure and temperature of refrigerant vapor
D. To meter refrigerant into the evaporator
Rationale: The compressor takes low-pressure, low-temperature
refrigerant vapor from the evaporator and compresses it into a high-
pressure, high-temperature vapor. This allows the refrigerant to reject
heat in the condenser.
2. Which component meters refrigerant entering the evaporator?
,A. Receiver
B. Compressor
C. Condenser
D. Expansion valve
Rationale: The expansion valve controls the flow of refrigerant into the
evaporator and creates a pressure drop. This pressure reduction allows
the refrigerant to evaporate at a lower temperature.
3. What is the primary purpose of the condenser?
A. Absorb heat from the conditioned space
B. Reject heat from the refrigerant to the surrounding medium
C. Increase refrigerant velocity
D. Reduce compressor discharge pressure
Rationale: The condenser removes heat from the high-pressure
refrigerant vapor. As heat is rejected, the refrigerant changes from
vapor to liquid.
4. What occurs to refrigerant pressure as it passes through a typical
expansion device?
A. It increases substantially
B. It remains constant
,C. It decreases
D. It becomes atmospheric
Rationale: The expansion device creates a controlled pressure drop
between the high-pressure liquid side and the low-pressure evaporator
side. The resulting lower pressure permits evaporation at a lower
temperature.
5. Which condition generally indicates insufficient evaporator
airflow in an air-cooled refrigeration system?
A. High airflow and low suction temperature
B. Low airflow with possible evaporator icing
C. High condenser airflow
D. High liquid-line temperature only
Rationale: Reduced airflow can cause the evaporator temperature to
fall below freezing, particularly in systems designed to operate above
freezing. Moisture can then freeze on the coil, further restricting airflow.
6. What is superheat?
A. The temperature of liquid below its saturation temperature
B. The pressure difference between suction and discharge
C. The temperature of a vapor above its saturation temperature at a
, given pressure
D. The temperature of the condenser above ambient
Rationale: Superheat is the number of degrees a vapor is heated above
its saturation temperature. In refrigeration systems, superheat
measurements help verify evaporator performance and refrigerant
feeding.
7. What does subcooling describe?
A. Vapor temperature below saturation
B. Compressor temperature below ambient
C. Liquid temperature below its saturation temperature at a given
pressure
D. Suction pressure below atmospheric pressure
Rationale: Subcooling occurs when liquid refrigerant is cooled below its
saturation temperature. Proper subcooling can help ensure that solid
liquid refrigerant reaches the metering device.
8. Which instrument is commonly used to measure refrigerant
pressure?
A. Megohmmeter
B. Clamp ammeter
Questions and Correct Answers (Verified
Answers) Plus Rationale 2027 Q&A|
Instant Download Pdf
1. What is the primary function of the compressor in a vapor-
compression refrigeration system?
A. To remove heat from the condenser
B. To lower the pressure of liquid refrigerant
C. To raise the pressure and temperature of refrigerant vapor
D. To meter refrigerant into the evaporator
Rationale: The compressor takes low-pressure, low-temperature
refrigerant vapor from the evaporator and compresses it into a high-
pressure, high-temperature vapor. This allows the refrigerant to reject
heat in the condenser.
2. Which component meters refrigerant entering the evaporator?
,A. Receiver
B. Compressor
C. Condenser
D. Expansion valve
Rationale: The expansion valve controls the flow of refrigerant into the
evaporator and creates a pressure drop. This pressure reduction allows
the refrigerant to evaporate at a lower temperature.
3. What is the primary purpose of the condenser?
A. Absorb heat from the conditioned space
B. Reject heat from the refrigerant to the surrounding medium
C. Increase refrigerant velocity
D. Reduce compressor discharge pressure
Rationale: The condenser removes heat from the high-pressure
refrigerant vapor. As heat is rejected, the refrigerant changes from
vapor to liquid.
4. What occurs to refrigerant pressure as it passes through a typical
expansion device?
A. It increases substantially
B. It remains constant
,C. It decreases
D. It becomes atmospheric
Rationale: The expansion device creates a controlled pressure drop
between the high-pressure liquid side and the low-pressure evaporator
side. The resulting lower pressure permits evaporation at a lower
temperature.
5. Which condition generally indicates insufficient evaporator
airflow in an air-cooled refrigeration system?
A. High airflow and low suction temperature
B. Low airflow with possible evaporator icing
C. High condenser airflow
D. High liquid-line temperature only
Rationale: Reduced airflow can cause the evaporator temperature to
fall below freezing, particularly in systems designed to operate above
freezing. Moisture can then freeze on the coil, further restricting airflow.
6. What is superheat?
A. The temperature of liquid below its saturation temperature
B. The pressure difference between suction and discharge
C. The temperature of a vapor above its saturation temperature at a
, given pressure
D. The temperature of the condenser above ambient
Rationale: Superheat is the number of degrees a vapor is heated above
its saturation temperature. In refrigeration systems, superheat
measurements help verify evaporator performance and refrigerant
feeding.
7. What does subcooling describe?
A. Vapor temperature below saturation
B. Compressor temperature below ambient
C. Liquid temperature below its saturation temperature at a given
pressure
D. Suction pressure below atmospheric pressure
Rationale: Subcooling occurs when liquid refrigerant is cooled below its
saturation temperature. Proper subcooling can help ensure that solid
liquid refrigerant reaches the metering device.
8. Which instrument is commonly used to measure refrigerant
pressure?
A. Megohmmeter
B. Clamp ammeter
