Ontario Refrigeration Operator Class B Exam (TSSA) QUESTIONS AND CORRECT
ANSWERS WITH RATIONALES
Exam Coverage
• TSSA Class B exam structure
• Refrigeration cycle
• Compressors and oil management
• Condensers and evaporators
• Expansion devices
• Pressure-temperature relationships
• Superheat and subcooling
• Refrigerant charging and evacuation
• Safety controls and relief devices
• Operating logs, troubleshooting, and maintenance
1. When evaluating a technical question about this topic, which statement provides the correct
interpretation of a filter-drier removes moisture and contaminants from a refrigeration circuit?
A) A filter-drier removes moisture and contaminants from a refrigeration circuit.
B) It is used only after the work is complete and has no effect on the technical process.
C) It is primarily a recordkeeping preference and does not materially affect safety or performance.
D) It applies only when every related component has already been removed from service.
,Correct Answer: A
Rationale: The selected response is supported by the rule or mechanism that Moisture and
contaminants can damage components and impair system performance. Therefore it best
represents competent understanding.
2. During a field inspection or work situation, which option correctly explains the expansion device
reduces refrigerant pressure before the evaporator and its practical purpose?
A) It is used only after the work is complete and has no effect on the technical process.
B) The expansion device reduces refrigerant pressure before the evaporator.
C) It is primarily a recordkeeping preference and does not materially affect safety or performance.
D) It applies only when every related component has already been removed from service.
Correct Answer: B
Rationale: The selected answer follows from the governing concept: The pressure reduction
allows refrigerant to enter the evaporator at a lower saturation temperature. That relationship is the
key distinction among the choices.
3. When an examinee compares several plausible responses, which statement best identifies the
correct concept concerning operator logs help identify trends and abnormal refrigeration
conditions?
A) It is used only after the work is complete and has no effect on the technical process.
B) It is primarily a recordkeeping preference and does not materially affect safety or performance.
C) Operator logs help identify trends and abnormal refrigeration conditions.
,D) It applies only when every related component has already been removed from service.
Correct Answer: C
Rationale: The reason this response is correct is that Recorded pressures, temperatures, alarms,
and operating observations support troubleshooting and preventive maintenance. Understanding
this mechanism supports both safe practice and accurate examination decisions.
4. Which choice best explains the relationship between the stated concept and the outcome
expected when applying subcooling is the temperature of liquid below its saturation temperature at
a given pressure?
A) It is used only after the work is complete and has no effect on the technical process.
B) It is primarily a recordkeeping preference and does not materially affect safety or performance.
C) It applies only when every related component has already been removed from service.
D) Subcooling is the temperature of liquid below its saturation temperature at a given pressure.
Correct Answer: D
Rationale: The technical basis is that Subcooling confirms liquid is cooled below saturation before
reaching the expansion device. Recognizing this prevents a common error in interpreting the
subject.
5. When an examinee compares several plausible responses, which statement best identifies the
correct concept concerning pressure-temperature relationships are used to interpret refrigerant
operating conditions?
A) Pressure-temperature relationships are used to interpret refrigerant operating conditions.
, B) It is used only after the work is complete and has no effect on the technical process.
C) It is primarily a recordkeeping preference and does not materially affect safety or performance.
D) It applies only when every related component has already been removed from service.
Correct Answer: A
Rationale: The reason this response is correct is that Refrigerant pressure corresponds to
saturation temperature for a given refrigerant. Understanding this mechanism supports both safe
practice and accurate examination decisions.
6. During a field inspection or work situation, which option correctly explains a filter-drier removes
moisture and contaminants from a refrigeration circuit and its practical purpose?
A) It is used only after the work is complete and has no effect on the technical process.
B) A filter-drier removes moisture and contaminants from a refrigeration circuit.
C) It is primarily a recordkeeping preference and does not materially affect safety or performance.
D) It applies only when every related component has already been removed from service.
Correct Answer: B
Rationale: The selected answer follows from the governing concept: Moisture and contaminants
can damage components and impair system performance. That relationship is the key distinction
among the choices.
7. A technician or inspector is reviewing this subject before performing work; which statement
correctly explains a cooling tower rejects heat from water to the atmosphere in applicable
systems?
ANSWERS WITH RATIONALES
Exam Coverage
• TSSA Class B exam structure
• Refrigeration cycle
• Compressors and oil management
• Condensers and evaporators
• Expansion devices
• Pressure-temperature relationships
• Superheat and subcooling
• Refrigerant charging and evacuation
• Safety controls and relief devices
• Operating logs, troubleshooting, and maintenance
1. When evaluating a technical question about this topic, which statement provides the correct
interpretation of a filter-drier removes moisture and contaminants from a refrigeration circuit?
A) A filter-drier removes moisture and contaminants from a refrigeration circuit.
B) It is used only after the work is complete and has no effect on the technical process.
C) It is primarily a recordkeeping preference and does not materially affect safety or performance.
D) It applies only when every related component has already been removed from service.
,Correct Answer: A
Rationale: The selected response is supported by the rule or mechanism that Moisture and
contaminants can damage components and impair system performance. Therefore it best
represents competent understanding.
2. During a field inspection or work situation, which option correctly explains the expansion device
reduces refrigerant pressure before the evaporator and its practical purpose?
A) It is used only after the work is complete and has no effect on the technical process.
B) The expansion device reduces refrigerant pressure before the evaporator.
C) It is primarily a recordkeeping preference and does not materially affect safety or performance.
D) It applies only when every related component has already been removed from service.
Correct Answer: B
Rationale: The selected answer follows from the governing concept: The pressure reduction
allows refrigerant to enter the evaporator at a lower saturation temperature. That relationship is the
key distinction among the choices.
3. When an examinee compares several plausible responses, which statement best identifies the
correct concept concerning operator logs help identify trends and abnormal refrigeration
conditions?
A) It is used only after the work is complete and has no effect on the technical process.
B) It is primarily a recordkeeping preference and does not materially affect safety or performance.
C) Operator logs help identify trends and abnormal refrigeration conditions.
,D) It applies only when every related component has already been removed from service.
Correct Answer: C
Rationale: The reason this response is correct is that Recorded pressures, temperatures, alarms,
and operating observations support troubleshooting and preventive maintenance. Understanding
this mechanism supports both safe practice and accurate examination decisions.
4. Which choice best explains the relationship between the stated concept and the outcome
expected when applying subcooling is the temperature of liquid below its saturation temperature at
a given pressure?
A) It is used only after the work is complete and has no effect on the technical process.
B) It is primarily a recordkeeping preference and does not materially affect safety or performance.
C) It applies only when every related component has already been removed from service.
D) Subcooling is the temperature of liquid below its saturation temperature at a given pressure.
Correct Answer: D
Rationale: The technical basis is that Subcooling confirms liquid is cooled below saturation before
reaching the expansion device. Recognizing this prevents a common error in interpreting the
subject.
5. When an examinee compares several plausible responses, which statement best identifies the
correct concept concerning pressure-temperature relationships are used to interpret refrigerant
operating conditions?
A) Pressure-temperature relationships are used to interpret refrigerant operating conditions.
, B) It is used only after the work is complete and has no effect on the technical process.
C) It is primarily a recordkeeping preference and does not materially affect safety or performance.
D) It applies only when every related component has already been removed from service.
Correct Answer: A
Rationale: The reason this response is correct is that Refrigerant pressure corresponds to
saturation temperature for a given refrigerant. Understanding this mechanism supports both safe
practice and accurate examination decisions.
6. During a field inspection or work situation, which option correctly explains a filter-drier removes
moisture and contaminants from a refrigeration circuit and its practical purpose?
A) It is used only after the work is complete and has no effect on the technical process.
B) A filter-drier removes moisture and contaminants from a refrigeration circuit.
C) It is primarily a recordkeeping preference and does not materially affect safety or performance.
D) It applies only when every related component has already been removed from service.
Correct Answer: B
Rationale: The selected answer follows from the governing concept: Moisture and contaminants
can damage components and impair system performance. That relationship is the key distinction
among the choices.
7. A technician or inspector is reviewing this subject before performing work; which statement
correctly explains a cooling tower rejects heat from water to the atmosphere in applicable
systems?
