FDNY Z-51 RMO Examination Questions
And Correct Answers (Verified Answers)
Plus Rationales 2026 Q&A | Instant
Download Pdf
1.
A refrigeration system using ammonia shows a slight pressure rise but no visible
leaks. The operator should FIRST:
A. Ignore condition
B. Check system operating parameters and perform leak inspection
C. Increase compressor speed
D. Vent system
Answer: B
Any abnormal pressure change requires immediate diagnostic checks.
2.
Which refrigerant is MOST commonly associated with toxic inhalation risk?
A. CO₂
B. Ammonia
C. R-134a
D. Water vapor
Answer: B
Ammonia is highly toxic and requires strict handling.
3.
A refrigeration compressor overheats. MOST likely cause:
,A. Overcooling
B. Insufficient lubrication or overload
C. Too much ventilation
D. Low ambient temperature only
Answer: B
Overheating typically results from mechanical or lubrication issues.
4.
A refrigerant leak is suspected in a machine room. FIRST action:
A. Continue operation
B. Evacuate and isolate area
C. Increase ventilation only
D. Shut lights off
Answer: B
Safety requires immediate evacuation for hazardous leaks.
5.
Which is a PRIMARY function of a refrigeration system?
A. Heating buildings
B. Removing heat from a space
C. Increasing humidity
D. Generating power
Answer: B
Refrigeration systems transfer heat out of controlled space.
6.
A pressure relief valve activates. This indicates:
,A. Normal operation always
B. Excess pressure condition
C. Low refrigerant level
D. System shutdown error
Answer: B
Relief valves open under overpressure conditions.
7.
Which condition requires immediate shutdown?
A. Normal vibration
B. Major refrigerant leak
C. Stable temperature
D. Low load operation
Answer: B
Leaks present immediate hazard.
8.
A condenser is dirty. Result:
A. Increased efficiency
B. Reduced heat transfer efficiency
C. No effect
D. Cooling increase
Answer: B
Dirty condensers reduce system performance.
9.
Compressor short cycling usually indicates:
, A. Stable system
B. Control or pressure imbalance
C. Proper function
D. Overcooling only
Answer: B
Short cycling indicates system instability.
10.
Which is MOST dangerous refrigerant condition?
A. Proper pressure
B. Toxic gas leak in confined space
C. Clean condenser
D. Stable operation
Answer: B
Confined toxic leaks are extremely hazardous.
11.
A low refrigerant charge typically causes:
A. High cooling output
B. Reduced cooling efficiency
C. Increased pressure
D. Compressor shutdown protection only
Answer: B
Low charge reduces system capacity.
12.
What is the purpose of a sight glass?
And Correct Answers (Verified Answers)
Plus Rationales 2026 Q&A | Instant
Download Pdf
1.
A refrigeration system using ammonia shows a slight pressure rise but no visible
leaks. The operator should FIRST:
A. Ignore condition
B. Check system operating parameters and perform leak inspection
C. Increase compressor speed
D. Vent system
Answer: B
Any abnormal pressure change requires immediate diagnostic checks.
2.
Which refrigerant is MOST commonly associated with toxic inhalation risk?
A. CO₂
B. Ammonia
C. R-134a
D. Water vapor
Answer: B
Ammonia is highly toxic and requires strict handling.
3.
A refrigeration compressor overheats. MOST likely cause:
,A. Overcooling
B. Insufficient lubrication or overload
C. Too much ventilation
D. Low ambient temperature only
Answer: B
Overheating typically results from mechanical or lubrication issues.
4.
A refrigerant leak is suspected in a machine room. FIRST action:
A. Continue operation
B. Evacuate and isolate area
C. Increase ventilation only
D. Shut lights off
Answer: B
Safety requires immediate evacuation for hazardous leaks.
5.
Which is a PRIMARY function of a refrigeration system?
A. Heating buildings
B. Removing heat from a space
C. Increasing humidity
D. Generating power
Answer: B
Refrigeration systems transfer heat out of controlled space.
6.
A pressure relief valve activates. This indicates:
,A. Normal operation always
B. Excess pressure condition
C. Low refrigerant level
D. System shutdown error
Answer: B
Relief valves open under overpressure conditions.
7.
Which condition requires immediate shutdown?
A. Normal vibration
B. Major refrigerant leak
C. Stable temperature
D. Low load operation
Answer: B
Leaks present immediate hazard.
8.
A condenser is dirty. Result:
A. Increased efficiency
B. Reduced heat transfer efficiency
C. No effect
D. Cooling increase
Answer: B
Dirty condensers reduce system performance.
9.
Compressor short cycling usually indicates:
, A. Stable system
B. Control or pressure imbalance
C. Proper function
D. Overcooling only
Answer: B
Short cycling indicates system instability.
10.
Which is MOST dangerous refrigerant condition?
A. Proper pressure
B. Toxic gas leak in confined space
C. Clean condenser
D. Stable operation
Answer: B
Confined toxic leaks are extremely hazardous.
11.
A low refrigerant charge typically causes:
A. High cooling output
B. Reduced cooling efficiency
C. Increased pressure
D. Compressor shutdown protection only
Answer: B
Low charge reduces system capacity.
12.
What is the purpose of a sight glass?
