California Commercial Refrigeration
Exam Practice Questions And Correct
Answers (Verified Answers) Plus
Rationale 2026 Q&A| Instant Download
Pdf
1. A refrigeration technician is troubleshooting a commercial walk-in
cooler that is failing to maintain proper temperature. The compressor
is running continuously, the evaporator fan is operating, and the
condenser coil is clean. Which of the following conditions is the MOST
likely cause of insufficient cooling performance in this system under
normal load conditions?
A. Overcharged refrigerant system causing excessive head pressure
and reduced evaporator efficiency
B. Restricted liquid line filter-drier causing starved evaporator
conditions and low suction pressure
C. Faulty condenser fan motor resulting in elevated discharge pressure
, and system shutdown
D. Evaporator fan running too fast causing frost buildup on the coil
surface
Answer: B
A restricted liquid line filter-drier reduces refrigerant flow to the
evaporator, causing low suction pressure and inadequate heat
absorption, which results in continuous compressor operation
without achieving target cooling temperatures.
2. A technician measures unusually high head pressure in a commercial
refrigeration system using R-404A. Ambient temperature is normal,
condenser airflow is adequate, and refrigerant charge appears correct.
Which condition is the MOST likely cause?
A. Undercharged system causing low suction pressure
B. Non-condensable gases trapped in the system
C. Low evaporator airflow due to dirty coil
D. Expansion valve stuck fully open
Answer: B
Non-condensable gases such as air in the system increase condensing
pressure without improving heat transfer, leading to abnormally
high head pressure even when other conditions are normal.
3. In a vapor-compression refrigeration cycle, the primary function of the
expansion device is to:
A. Increase refrigerant pressure before entering the condenser
, B. Convert low-pressure vapor into high-pressure liquid
C. Meter refrigerant flow and reduce pressure before the evaporator
D. Compress refrigerant into a high-temperature gas
Answer: C
The expansion device controls refrigerant flow and reduces pressure
so the refrigerant can absorb heat efficiently in the evaporator.
4. A walk-in freezer has heavy frost forming on the evaporator coil
despite proper defrost cycle operation. Which issue is MOST likely
responsible?
A. Defrost timer set too frequently
B. Air infiltration due to damaged door seals
C. Oversized condenser fan motor
D. High superheat setting on compressor
Answer: B
Air infiltration introduces moisture into the freezer, which freezes on
the evaporator coil and leads to excessive frost buildup even with
proper defrost cycles.
5. Which instrument is MOST appropriate for measuring superheat in a
refrigeration system?
A. Clamp meter
B. Manifold gauge set and temperature probe
C. Psychrometer
D. Megohmmeter
, Answer: B
Superheat is determined using suction pressure from a manifold
gauge and line temperature from a probe to calculate refrigerant
condition at the evaporator outlet.
6. A refrigeration system shows low suction pressure and low discharge
pressure. The technician suspects a refrigerant issue. What is the
MOST probable cause?
A. Overcharged system
B. Undercharged system
C. Dirty condenser coil
D. Faulty compressor valves stuck open
Answer: B
An undercharged system lacks sufficient refrigerant mass, resulting
in low pressures on both the suction and discharge sides.
7. In commercial refrigeration, the condenser’s primary function is to:
A. Absorb heat from the refrigerated space
B. Reject heat absorbed from the evaporator to the surrounding
environment
C. Control refrigerant flow into the compressor
D. Increase refrigerant velocity for cooling efficiency
Answer: B
The condenser releases heat from the refrigerant to the surrounding
air or water, allowing the refrigerant to change from vapor to liquid.
Exam Practice Questions And Correct
Answers (Verified Answers) Plus
Rationale 2026 Q&A| Instant Download
1. A refrigeration technician is troubleshooting a commercial walk-in
cooler that is failing to maintain proper temperature. The compressor
is running continuously, the evaporator fan is operating, and the
condenser coil is clean. Which of the following conditions is the MOST
likely cause of insufficient cooling performance in this system under
normal load conditions?
A. Overcharged refrigerant system causing excessive head pressure
and reduced evaporator efficiency
B. Restricted liquid line filter-drier causing starved evaporator
conditions and low suction pressure
C. Faulty condenser fan motor resulting in elevated discharge pressure
, and system shutdown
D. Evaporator fan running too fast causing frost buildup on the coil
surface
Answer: B
A restricted liquid line filter-drier reduces refrigerant flow to the
evaporator, causing low suction pressure and inadequate heat
absorption, which results in continuous compressor operation
without achieving target cooling temperatures.
2. A technician measures unusually high head pressure in a commercial
refrigeration system using R-404A. Ambient temperature is normal,
condenser airflow is adequate, and refrigerant charge appears correct.
Which condition is the MOST likely cause?
A. Undercharged system causing low suction pressure
B. Non-condensable gases trapped in the system
C. Low evaporator airflow due to dirty coil
D. Expansion valve stuck fully open
Answer: B
Non-condensable gases such as air in the system increase condensing
pressure without improving heat transfer, leading to abnormally
high head pressure even when other conditions are normal.
3. In a vapor-compression refrigeration cycle, the primary function of the
expansion device is to:
A. Increase refrigerant pressure before entering the condenser
, B. Convert low-pressure vapor into high-pressure liquid
C. Meter refrigerant flow and reduce pressure before the evaporator
D. Compress refrigerant into a high-temperature gas
Answer: C
The expansion device controls refrigerant flow and reduces pressure
so the refrigerant can absorb heat efficiently in the evaporator.
4. A walk-in freezer has heavy frost forming on the evaporator coil
despite proper defrost cycle operation. Which issue is MOST likely
responsible?
A. Defrost timer set too frequently
B. Air infiltration due to damaged door seals
C. Oversized condenser fan motor
D. High superheat setting on compressor
Answer: B
Air infiltration introduces moisture into the freezer, which freezes on
the evaporator coil and leads to excessive frost buildup even with
proper defrost cycles.
5. Which instrument is MOST appropriate for measuring superheat in a
refrigeration system?
A. Clamp meter
B. Manifold gauge set and temperature probe
C. Psychrometer
D. Megohmmeter
, Answer: B
Superheat is determined using suction pressure from a manifold
gauge and line temperature from a probe to calculate refrigerant
condition at the evaporator outlet.
6. A refrigeration system shows low suction pressure and low discharge
pressure. The technician suspects a refrigerant issue. What is the
MOST probable cause?
A. Overcharged system
B. Undercharged system
C. Dirty condenser coil
D. Faulty compressor valves stuck open
Answer: B
An undercharged system lacks sufficient refrigerant mass, resulting
in low pressures on both the suction and discharge sides.
7. In commercial refrigeration, the condenser’s primary function is to:
A. Absorb heat from the refrigerated space
B. Reject heat absorbed from the evaporator to the surrounding
environment
C. Control refrigerant flow into the compressor
D. Increase refrigerant velocity for cooling efficiency
Answer: B
The condenser releases heat from the refrigerant to the surrounding
air or water, allowing the refrigerant to change from vapor to liquid.
