NYC Health Hospitals Senior
Refrigeration Engineer Exam Practice
Questions And Correct Answers
(Verified Answers) Plus Rationale 2026
Q&A| Instant Download Pdf
1.During a routine inspection of a large centrifugal chiller serving a NYC
Health + Hospitals facility, a Senior Refrigeration Engineer notices that the
compressor motor amperage has steadily increased over several weeks
while the evaporator load has remained relatively constant. The condenser
water temperature and flow rate are within design limits, but the condenser
approach temperature has increased significantly. Which condition is the
most likely cause of the increased motor amperage?
A. Excessive chilled water flow through the evaporator
B. Fouled condenser tubes reducing heat transfer efficiency
C. Undersized chilled water pump causing low evaporator flow
D. Defective expansion valve allowing excessive refrigerant flow
,B. Fouled condenser tubes reducing heat transfer efficiency
Rationale: Fouled condenser tubes reduce the condenser's ability to reject
heat, forcing the compressor to operate at a higher condensing pressure.
This increases compressor workload and motor amperage while condenser
water conditions remain normal. An increased condenser approach
temperature is a classic indication of fouled heat-transfer surfaces.
2. A hospital's ammonia refrigeration system experiences frequent high-
pressure cutout trips during periods of high outdoor temperatures.
Cooling tower fans, condenser pumps, and refrigerant charge have all
been verified as satisfactory. Which additional condition should be
investigated first because it can directly increase condensing pressure?
A. Low oil level in the compressor crankcase
B. Air and other non-condensable gases trapped in the condenser
C. Excessive insulation on suction piping
D. High evaporator superheat setting only
B. Air and other non-condensable gases trapped in the condenser
Rationale: Non-condensable gases occupy condenser space and elevate
condensing pressure because they cannot be condensed along with the
refrigerant. This causes excessive head pressure and frequent high-
pressure safety trips, particularly during warm weather when condenser
capacity is already challenged.
, 3. Before performing maintenance on a refrigeration compressor
connected to an electrically driven motor, which procedure provides
the greatest protection against accidental equipment startup and
serious injury?
A. Place the selector switch in the OFF position only.
B. Inform nearby employees that maintenance is beginning.
C. Apply lockout/tagout procedures, isolate all energy sources, and verify
zero energy before beginning work.
D. Remove the compressor belts before beginning maintenance.
C. Apply lockout/tagout procedures, isolate all energy sources, and verify
zero energy before beginning work.
Rationale: OSHA-required lockout/tagout procedures protect workers by
isolating all hazardous energy sources and verifying that equipment
cannot be energized unexpectedly. Simply turning equipment off or
notifying others does not eliminate hazardous stored energy.
4. A reciprocating refrigeration compressor consistently exhibits low
suction pressure, high superheat, and reduced cooling capacity.
Inspection reveals that the evaporator is receiving insufficient
refrigerant despite an adequate refrigerant charge. Which component
is the most likely source of the problem?
A. Thermostatic expansion valve restricted or malfunctioning
B. Condenser fan operating continuously
, C. Oil separator functioning normally
D. Compressor discharge service valve fully open
A. Thermostatic expansion valve restricted or malfunctioning
Rationale: A restricted or malfunctioning thermostatic expansion valve
limits refrigerant flow into the evaporator, producing low suction pressure,
excessive superheat, and reduced system capacity. These symptoms are
characteristic of an underfed evaporator.
5. In a hospital environment, why is maintaining proper refrigeration
system oil levels particularly important in large compressors?
A. Oil primarily increases refrigerant pressure.
B. Oil serves as the primary refrigerant within the evaporator.
C. Oil lubricates moving parts, removes heat, minimizes wear, and
contributes to compressor reliability.
D. Oil eliminates the need for refrigerant filtration.
C. Oil lubricates moving parts, removes heat, minimizes wear, and
contributes to compressor reliability.
Rationale: Compressor oil provides essential lubrication, assists in heat
removal, seals internal clearances, and reduces wear. Insufficient oil can
rapidly result in bearing damage, overheating, and catastrophic
compressor failure.
Refrigeration Engineer Exam Practice
Questions And Correct Answers
(Verified Answers) Plus Rationale 2026
Q&A| Instant Download Pdf
1.During a routine inspection of a large centrifugal chiller serving a NYC
Health + Hospitals facility, a Senior Refrigeration Engineer notices that the
compressor motor amperage has steadily increased over several weeks
while the evaporator load has remained relatively constant. The condenser
water temperature and flow rate are within design limits, but the condenser
approach temperature has increased significantly. Which condition is the
most likely cause of the increased motor amperage?
A. Excessive chilled water flow through the evaporator
B. Fouled condenser tubes reducing heat transfer efficiency
C. Undersized chilled water pump causing low evaporator flow
D. Defective expansion valve allowing excessive refrigerant flow
,B. Fouled condenser tubes reducing heat transfer efficiency
Rationale: Fouled condenser tubes reduce the condenser's ability to reject
heat, forcing the compressor to operate at a higher condensing pressure.
This increases compressor workload and motor amperage while condenser
water conditions remain normal. An increased condenser approach
temperature is a classic indication of fouled heat-transfer surfaces.
2. A hospital's ammonia refrigeration system experiences frequent high-
pressure cutout trips during periods of high outdoor temperatures.
Cooling tower fans, condenser pumps, and refrigerant charge have all
been verified as satisfactory. Which additional condition should be
investigated first because it can directly increase condensing pressure?
A. Low oil level in the compressor crankcase
B. Air and other non-condensable gases trapped in the condenser
C. Excessive insulation on suction piping
D. High evaporator superheat setting only
B. Air and other non-condensable gases trapped in the condenser
Rationale: Non-condensable gases occupy condenser space and elevate
condensing pressure because they cannot be condensed along with the
refrigerant. This causes excessive head pressure and frequent high-
pressure safety trips, particularly during warm weather when condenser
capacity is already challenged.
, 3. Before performing maintenance on a refrigeration compressor
connected to an electrically driven motor, which procedure provides
the greatest protection against accidental equipment startup and
serious injury?
A. Place the selector switch in the OFF position only.
B. Inform nearby employees that maintenance is beginning.
C. Apply lockout/tagout procedures, isolate all energy sources, and verify
zero energy before beginning work.
D. Remove the compressor belts before beginning maintenance.
C. Apply lockout/tagout procedures, isolate all energy sources, and verify
zero energy before beginning work.
Rationale: OSHA-required lockout/tagout procedures protect workers by
isolating all hazardous energy sources and verifying that equipment
cannot be energized unexpectedly. Simply turning equipment off or
notifying others does not eliminate hazardous stored energy.
4. A reciprocating refrigeration compressor consistently exhibits low
suction pressure, high superheat, and reduced cooling capacity.
Inspection reveals that the evaporator is receiving insufficient
refrigerant despite an adequate refrigerant charge. Which component
is the most likely source of the problem?
A. Thermostatic expansion valve restricted or malfunctioning
B. Condenser fan operating continuously
, C. Oil separator functioning normally
D. Compressor discharge service valve fully open
A. Thermostatic expansion valve restricted or malfunctioning
Rationale: A restricted or malfunctioning thermostatic expansion valve
limits refrigerant flow into the evaporator, producing low suction pressure,
excessive superheat, and reduced system capacity. These symptoms are
characteristic of an underfed evaporator.
5. In a hospital environment, why is maintaining proper refrigeration
system oil levels particularly important in large compressors?
A. Oil primarily increases refrigerant pressure.
B. Oil serves as the primary refrigerant within the evaporator.
C. Oil lubricates moving parts, removes heat, minimizes wear, and
contributes to compressor reliability.
D. Oil eliminates the need for refrigerant filtration.
C. Oil lubricates moving parts, removes heat, minimizes wear, and
contributes to compressor reliability.
Rationale: Compressor oil provides essential lubrication, assists in heat
removal, seals internal clearances, and reduces wear. Insufficient oil can
rapidly result in bearing damage, overheating, and catastrophic
compressor failure.
