Examination — Local Jurisdiction
Practice Exam 2026 | 100 Questions &
Answers with Detailed Rationales |
Complete Exam Prep & Study Guide
1. A refrigeration system uses a receiver to store liquid refrigerant. What is
the primary purpose of the receiver in a system equipped with a
thermostatic expansion valve?
A. Increase compressor discharge pressure
B. Provide a reservoir of liquid refrigerant and maintain a solid liquid supply to
the metering device
C. Remove noncondensable gases
D. Increase evaporator superheat
Answer: B. Provide a reservoir of liquid refrigerant and maintain a solid liquid
supply to the metering device
,Rationale: A receiver stores excess liquid refrigerant and helps ensure that the
expansion device receives a continuous column of liquid under varying load and
operating conditions.
2. A refrigeration compressor is operating with abnormally high discharge
pressure while suction pressure is also elevated. Which condition is most
likely?
A. Low evaporator load
B. Starved evaporator
C. High condenser load or inadequate condenser heat rejection
D. Restricted suction line
Answer: C. High condenser load or inadequate condenser heat rejection
Rationale: A dirty condenser, failed condenser fan, excessive ambient
temperature, or noncondensables can reduce heat rejection and raise
condensing pressure while increasing suction pressure under certain load
conditions.
3. What is the principal purpose of compressor superheat protection?
A. Prevent liquid refrigerant from entering the condenser
B. Increase refrigerant flow through the receiver
C. Prevent liquid refrigerant from returning to the compressor
D. Lower condensing temperature
Answer: C. Prevent liquid refrigerant from returning to the compressor
Rationale: Compressors are designed primarily to compress vapor. Liquid
returning to the compressor can cause oil dilution, bearing damage, valve
damage, and hydraulic slugging.
4. A system has a 40°F saturated evaporating temperature and 50°F suction-
line temperature measured at the evaporator outlet. What is the
evaporator outlet superheat?
,A. 5°F
B. 10°F
C. 40°F
D. 90°F
Answer: B. 10°F
Rationale: Superheat equals the actual vapor temperature minus the saturation
temperature: 50°F − 40°F = 10°F.
5. A condenser has a 100°F condensing saturation temperature while outdoor
air entering the condenser is 80°F. What is the condenser temperature
difference?
A. 10°F
B. 20°F
C. 80°F
D. 180°F
Answer: B. 20°F
Rationale: Condenser TD is generally calculated as condensing saturation
temperature minus entering air temperature. Therefore, 100°F − 80°F = 20°F.
6. What is the most appropriate method for confirming that a thermostatic
expansion valve is properly controlling evaporator superheat?
A. Measure compressor discharge temperature only
B. Measure condenser subcooling only
C. Measure evaporator outlet temperature and corresponding refrigerant
saturation temperature
D. Measure liquid receiver temperature only
Answer: C. Measure evaporator outlet temperature and corresponding
refrigerant saturation temperature
, Rationale: TXV adjustment and diagnosis require determining actual superheat
at the appropriate sensing location and comparing it with the system design
requirement.
7. Excessive liquid subcooling immediately downstream of a condenser may
indicate:
A. Low refrigerant charge in every case
B. Liquid refrigerant backed up in the condenser or liquid line
C. Excessive suction superheat
D. Compressor valve leakage only
Answer: B. Liquid refrigerant backed up in the condenser or liquid line
Rationale: Excessive subcooling can occur when liquid refrigerant accumulates
in the condenser because of restricted liquid flow, overcharge, or other system
conditions. Diagnosis must consider the entire system.
8. Which component removes moisture and certain contaminants from a
refrigeration system?
A. Accumulator
B. Receiver
C. Filter-drier
D. Oil separator
Answer: C. Filter-drier
Rationale: Filter-driers are designed to remove moisture, acids, particulates, and
other contaminants depending on their construction and application.
9. Why is evacuation performed before charging a newly opened refrigeration
system?
A. To increase refrigerant pressure
B. To raise compressor oil temperature
C. To remove air, moisture, and other noncondensable gases from the system
D. To increase liquid subcooling