RETA CIRO SYSTEM PERFORMANCE
ANALYSIS PRACTICE EXAM WITH
QUESTIONS AND VERIFIED ANSWERS,
PLUS DETAILED RATIONALES/EXPERT
VERIFIED FOR GUARANTEED PASS
2026/LATEST UPDATE/INSTANT
DOWNLOAD PDF
1.
A refrigeration operator notices that an evaporator serving a -10°F (-
23.3°C) freezer is operating with a suction pressure corresponding to an
evaporating temperature of -20°F (-28.9°C). The product load has
remained essentially unchanged, condenser conditions are normal, and
the evaporator superheat is substantially higher than its normal value.
Which condition most directly explains the loss of evaporator capacity?
A. Excessive condenser subcooling
B. Excessive liquid refrigerant feed to the evaporator
C. Insufficient refrigerant flow through the evaporator
D. Excessive compressor volumetric efficiency
Answer: C. Insufficient refrigerant flow through the evaporator
Rationale: An evaporator depends on adequate refrigerant flow to
absorb the available heat load. When refrigerant feed is restricted,
only part of the evaporator surface is effectively wetted, causing the
suction pressure to fall and superheat to rise. Possible causes include a
restricted valve, plugged strainer, inadequate differential pressure
across the expansion device, or an improperly adjusted control valve.
2.
1
,During routine system-performance trending, an operator observes that
compressor discharge pressure has gradually increased over several
weeks while the evaporating pressure and refrigeration load have
remained relatively stable. Which trend should receive the greatest
initial attention?
A. Condenser performance and heat rejection
B. Evaporator fan rotation
C. Compressor crankcase oil level only
D. Expansion-valve bulb location
Answer: A. Condenser performance and heat rejection
Rationale: Rising condensing pressure at relatively stable evaporating
conditions commonly indicates deteriorating condenser performance.
Possible contributors include fouled heat-transfer surfaces,
inadequate cooling-water flow, elevated entering-water or ambient
conditions, excessive non-condensable gases, or inadequate condenser
capacity.
3.
An ammonia system's condensing pressure is significantly higher than
expected based on the measured outdoor temperature and the normal
condenser approach. The operator confirms that condenser water flow is
adequate and the heat-transfer surfaces are clean. Which additional
condition should be investigated?
A. Low evaporator superheat
B. Non-condensable gases in the high side
C. Excessive compressor suction temperature caused by liquid carryover
D. Low oil temperature in the evaporator
Answer: B. Non-condensable gases in the high side
2
,Rationale: Non-condensable gases can accumulate in condenser or
receiver areas and raise the total pressure above the pressure
corresponding to the actual ammonia condensing temperature. This
increases compressor lift and power consumption while reducing
overall system efficiency. Proper purging procedures and
manufacturer/site procedures should be followed.
4.
A plant operates a compressor at a suction pressure corresponding to -
25°F and a discharge pressure corresponding to 90°F condensing
temperature. Another compressor in the same system operates at a
considerably lower condensing pressure while serving the same
refrigeration duty. Which measurement would best help identify whether
the first compressor is experiencing unusually high compression losses?
A. Compressor amperage and discharge temperature
B. Receiver liquid level only
C. Evaporator room temperature only
D. Ambient relative humidity only
Answer: A. Compressor amperage and discharge temperature
Rationale: Compressor amperage and discharge temperature provide
valuable indicators of compression work and operating stress.
Excessive compression ratio, valve problems, high discharge
superheat, inadequate cooling, or internal mechanical problems can
increase both electrical demand and discharge temperature. These
measurements should be evaluated alongside suction and discharge
pressures.
5.
3
, A refrigeration system's suction pressure is lower than normal, but the
evaporator outlet superheat is also lower than normal. Which condition
is most consistent with this combination?
A. Severely restricted liquid feed
B. Excessive evaporator refrigerant feed or poor load matching
C. Excessive condenser subcooling alone
D. Completely empty receiver
Answer: B. Excessive evaporator refrigerant feed or poor load
matching
Rationale: A low suction pressure does not automatically mean
insufficient refrigerant feed. If superheat is also low, the evaporator
may be overfed relative to the available heat load, or the suction
pressure may be depressed by other system conditions. Low superheat
is particularly important because it can indicate inadequate
vaporization before refrigerant reaches the compressor.
6.
Which performance parameter is most useful for determining how hard a
refrigeration compressor is working relative to its evaporating
condition?
A. Compressor suction pressure alone
B. Compression ratio
C. Receiver liquid level
D. Oil separator temperature alone
Answer: B. Compression ratio
Rationale: Compression ratio compares absolute discharge pressure
with absolute suction pressure. As compression ratio increases,
compressor work generally increases and volumetric efficiency tends
4
ANALYSIS PRACTICE EXAM WITH
QUESTIONS AND VERIFIED ANSWERS,
PLUS DETAILED RATIONALES/EXPERT
VERIFIED FOR GUARANTEED PASS
2026/LATEST UPDATE/INSTANT
DOWNLOAD PDF
1.
A refrigeration operator notices that an evaporator serving a -10°F (-
23.3°C) freezer is operating with a suction pressure corresponding to an
evaporating temperature of -20°F (-28.9°C). The product load has
remained essentially unchanged, condenser conditions are normal, and
the evaporator superheat is substantially higher than its normal value.
Which condition most directly explains the loss of evaporator capacity?
A. Excessive condenser subcooling
B. Excessive liquid refrigerant feed to the evaporator
C. Insufficient refrigerant flow through the evaporator
D. Excessive compressor volumetric efficiency
Answer: C. Insufficient refrigerant flow through the evaporator
Rationale: An evaporator depends on adequate refrigerant flow to
absorb the available heat load. When refrigerant feed is restricted,
only part of the evaporator surface is effectively wetted, causing the
suction pressure to fall and superheat to rise. Possible causes include a
restricted valve, plugged strainer, inadequate differential pressure
across the expansion device, or an improperly adjusted control valve.
2.
1
,During routine system-performance trending, an operator observes that
compressor discharge pressure has gradually increased over several
weeks while the evaporating pressure and refrigeration load have
remained relatively stable. Which trend should receive the greatest
initial attention?
A. Condenser performance and heat rejection
B. Evaporator fan rotation
C. Compressor crankcase oil level only
D. Expansion-valve bulb location
Answer: A. Condenser performance and heat rejection
Rationale: Rising condensing pressure at relatively stable evaporating
conditions commonly indicates deteriorating condenser performance.
Possible contributors include fouled heat-transfer surfaces,
inadequate cooling-water flow, elevated entering-water or ambient
conditions, excessive non-condensable gases, or inadequate condenser
capacity.
3.
An ammonia system's condensing pressure is significantly higher than
expected based on the measured outdoor temperature and the normal
condenser approach. The operator confirms that condenser water flow is
adequate and the heat-transfer surfaces are clean. Which additional
condition should be investigated?
A. Low evaporator superheat
B. Non-condensable gases in the high side
C. Excessive compressor suction temperature caused by liquid carryover
D. Low oil temperature in the evaporator
Answer: B. Non-condensable gases in the high side
2
,Rationale: Non-condensable gases can accumulate in condenser or
receiver areas and raise the total pressure above the pressure
corresponding to the actual ammonia condensing temperature. This
increases compressor lift and power consumption while reducing
overall system efficiency. Proper purging procedures and
manufacturer/site procedures should be followed.
4.
A plant operates a compressor at a suction pressure corresponding to -
25°F and a discharge pressure corresponding to 90°F condensing
temperature. Another compressor in the same system operates at a
considerably lower condensing pressure while serving the same
refrigeration duty. Which measurement would best help identify whether
the first compressor is experiencing unusually high compression losses?
A. Compressor amperage and discharge temperature
B. Receiver liquid level only
C. Evaporator room temperature only
D. Ambient relative humidity only
Answer: A. Compressor amperage and discharge temperature
Rationale: Compressor amperage and discharge temperature provide
valuable indicators of compression work and operating stress.
Excessive compression ratio, valve problems, high discharge
superheat, inadequate cooling, or internal mechanical problems can
increase both electrical demand and discharge temperature. These
measurements should be evaluated alongside suction and discharge
pressures.
5.
3
, A refrigeration system's suction pressure is lower than normal, but the
evaporator outlet superheat is also lower than normal. Which condition
is most consistent with this combination?
A. Severely restricted liquid feed
B. Excessive evaporator refrigerant feed or poor load matching
C. Excessive condenser subcooling alone
D. Completely empty receiver
Answer: B. Excessive evaporator refrigerant feed or poor load
matching
Rationale: A low suction pressure does not automatically mean
insufficient refrigerant feed. If superheat is also low, the evaporator
may be overfed relative to the available heat load, or the suction
pressure may be depressed by other system conditions. Low superheat
is particularly important because it can indicate inadequate
vaporization before refrigerant reaches the compressor.
6.
Which performance parameter is most useful for determining how hard a
refrigeration compressor is working relative to its evaporating
condition?
A. Compressor suction pressure alone
B. Compression ratio
C. Receiver liquid level
D. Oil separator temperature alone
Answer: B. Compression ratio
Rationale: Compression ratio compares absolute discharge pressure
with absolute suction pressure. As compression ratio increases,
compressor work generally increases and volumetric efficiency tends
4
