FDNY Z-55 High Pressure Refrigeration
Systems Examination Questions And
Correct Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant
Download Pdf
1. The primary hazard of high-pressure refrigeration systems is:
A. Low temperature only
B. Sudden release of pressurized refrigerant
C. Electrical noise
D. Increased humidity
Answer: B. Sudden release of pressurized refrigerant
Rationale: High-pressure systems can rupture violently if compromised.
2. Case: A refrigeration line bursts under load. Immediate concern is:
A. Toxic refrigerant exposure and rapid pressure release
B. Cooling improvement
C. System efficiency gain
D. Reduced noise
Answer: A. Toxic refrigerant exposure and rapid pressure release
Rationale: Sudden release can cause asphyxiation and frost injury.
3. The purpose of a compressor in refrigeration is to:
A. Increase refrigerant pressure and circulate it
B. Reduce temperature directly
,C. Store refrigerant
D. Remove moisture only
Answer: A. Increase refrigerant pressure and circulate it
Rationale: Compression drives system circulation.
4. Case: Compressor runs continuously without cycling off. Likely cause:
A. Thermostat or control failure
B. Proper operation
C. Excess insulation
D. Low ambient noise
Answer: A. Thermostat or control failure
Rationale: System cannot reach set temperature.
5. The function of evaporator coils is to:
A. Absorb heat from the environment
B. Increase pressure
C. Store refrigerant
D. Compress gas
Answer: A. Absorb heat from the environment
Rationale: Evaporation removes heat energy.
6. Case: Ice buildup on evaporator coils. Likely cause:
A. Airflow restriction or low refrigerant flow
B. Proper operation
C. High pressure only
D. Electrical surge
Answer: A. Airflow restriction or low refrigerant flow
Rationale: Poor heat exchange causes freezing.
, 7. The purpose of refrigerant is to:
A. Transfer heat within the system
B. Generate electricity
C. Increase pressure only
D. Lubricate compressor
Answer: A. Transfer heat within the system
Rationale: Refrigerant cycles heat energy.
8. Case: Refrigerant leak detected in enclosed room. First action:
A. Evacuate and ventilate area
B. Ignore if small
C. Increase system load
D. Seal room immediately
Answer: A. Evacuate and ventilate area
Rationale: Refrigerants can displace oxygen.
9. The most dangerous property of many refrigerants is:
A. Asphyxiation risk in confined spaces
B. Color change
C. High viscosity
D. Electrical conductivity
Answer: A. Asphyxiation risk in confined spaces
Rationale: Oxygen displacement is life-threatening.
10. Case: Pressure gauge shows abnormally high discharge pressure. Likely
cause:
A. Condenser blockage or overheating
B. Low load
Systems Examination Questions And
Correct Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant
Download Pdf
1. The primary hazard of high-pressure refrigeration systems is:
A. Low temperature only
B. Sudden release of pressurized refrigerant
C. Electrical noise
D. Increased humidity
Answer: B. Sudden release of pressurized refrigerant
Rationale: High-pressure systems can rupture violently if compromised.
2. Case: A refrigeration line bursts under load. Immediate concern is:
A. Toxic refrigerant exposure and rapid pressure release
B. Cooling improvement
C. System efficiency gain
D. Reduced noise
Answer: A. Toxic refrigerant exposure and rapid pressure release
Rationale: Sudden release can cause asphyxiation and frost injury.
3. The purpose of a compressor in refrigeration is to:
A. Increase refrigerant pressure and circulate it
B. Reduce temperature directly
,C. Store refrigerant
D. Remove moisture only
Answer: A. Increase refrigerant pressure and circulate it
Rationale: Compression drives system circulation.
4. Case: Compressor runs continuously without cycling off. Likely cause:
A. Thermostat or control failure
B. Proper operation
C. Excess insulation
D. Low ambient noise
Answer: A. Thermostat or control failure
Rationale: System cannot reach set temperature.
5. The function of evaporator coils is to:
A. Absorb heat from the environment
B. Increase pressure
C. Store refrigerant
D. Compress gas
Answer: A. Absorb heat from the environment
Rationale: Evaporation removes heat energy.
6. Case: Ice buildup on evaporator coils. Likely cause:
A. Airflow restriction or low refrigerant flow
B. Proper operation
C. High pressure only
D. Electrical surge
Answer: A. Airflow restriction or low refrigerant flow
Rationale: Poor heat exchange causes freezing.
, 7. The purpose of refrigerant is to:
A. Transfer heat within the system
B. Generate electricity
C. Increase pressure only
D. Lubricate compressor
Answer: A. Transfer heat within the system
Rationale: Refrigerant cycles heat energy.
8. Case: Refrigerant leak detected in enclosed room. First action:
A. Evacuate and ventilate area
B. Ignore if small
C. Increase system load
D. Seal room immediately
Answer: A. Evacuate and ventilate area
Rationale: Refrigerants can displace oxygen.
9. The most dangerous property of many refrigerants is:
A. Asphyxiation risk in confined spaces
B. Color change
C. High viscosity
D. Electrical conductivity
Answer: A. Asphyxiation risk in confined spaces
Rationale: Oxygen displacement is life-threatening.
10. Case: Pressure gauge shows abnormally high discharge pressure. Likely
cause:
A. Condenser blockage or overheating
B. Low load
