ONTARIO REFRIGERATION OPERATOR CLASS B (TSSA)
CERTIFICATION — 200 HIGH-YIELD EXAM QUESTIONS
COMPLETE WITH VERIFIED ANSWERS
1. Which regulation under the Technical Standards and Safety Act, 2000
specifically governs the certification, staffing, and operation of
refrigeration plants in Ontario?
A) Ontario Regulation 213/07
B) Ontario Regulation 219/01
C) Ontario Regulation 223/01
D) Ontario Regulation 847/00
Rationale: Ontario Regulation 219/01 (Operating Engineers) establishes
the requirements for certification, staffing, operation, maintenance,
inspection, and testing of compressor plants and refrigeration plants in
Ontario.
2. What is the primary purpose of CSA B52?
A) To establish energy efficiency ratings for refrigeration equipment
B) To regulate refrigerant pricing across Canada
C) To minimize the risk of personal injury through safety requirements
for refrigeration system design, installation, and operation
D) To certify refrigeration technicians
Rationale: CSA B52 is fundamentally a safety standard focused on
reducing personal injury risk through requirements for design,
installation, inspection, and maintenance of refrigeration systems.
,3. A refrigeration system using R-717 (ammonia) requires what specific
safety classification under ANSI/ASHRAE 34?
A) A1
B) B2L
C) A2
D) B1
Rationale: R-717 (Ammonia) is classified as a B2L refrigerant, indicating
high toxicity and moderate flammability, which dictates specific safety
protocols and equipment requirements.
4. What is the minimum practical operating experience required in a
Class A or B refrigeration plant to challenge the TSSA Class B
certification exam for candidates who have not completed a TSSA-
approved time-reduction program?
A) 720 hours
B) 1,280 hours
C) 1,440 hours
D) 2,160 hours
Rationale: TSSA guidelines require 1,440 hours of practical training in a
Class A or B refrigeration plant for Class B certification. For candidates
who have completed a full-time TSSA-approved time-reduction
program, the requirement is reduced to 1,280 hours.
5. Which personal protective equipment is essential when responding
to an ammonia leak in a refrigeration plant?
A) Dust mask and safety glasses
B) Full-face respirator with ammonia cartridges and chemical-resistant
gloves
,C) Earplugs and hard hat
D) Face shield and cotton gloves
Rationale: Ammonia (R-717) is highly toxic and requires a full-face
respirator with appropriate cartridges and chemical-resistant gloves to
protect against exposure. CSA Z94.4 provides requirements for
respirator selection and use.
6. What is the primary function of a purge unit on a low-pressure
centrifugal chiller?
A) To lubricate the compressor bearings during startup
B) To remove non-condensable gases from the condenser
C) To prevent the evaporator from freezing
D) To recover refrigerant for recharging
Rationale: Non-condensable gases such as air and water vapor can
enter the system and accumulate in the condenser, raising the head
pressure. A purge unit removes them, improving efficiency.
7. What is the primary effect of non-condensable gases (air) in the
condenser?
A) Lowered discharge pressure
B) Decreased compressor amp draw
C) Increased condensing pressure and temperature
D) Increased subcooling
Rationale: Non-condensables occupy volume in the condenser, raising
the head pressure and requiring the compressor to work harder, which
reduces efficiency and increases energy consumption.
8. Which code governs the mechanical safety requirements for the
design, construction, installation, and inspection of refrigeration
, systems in Ontario?
A) CSA B51
B) CSA B52
C) ASHRAE 15
D) CSA B149.1
Rationale: CSA B52: Mechanical Refrigeration Code sets the standards
for safety in refrigeration systems in Ontario. CSA B51 covers boilers and
pressure vessels.
9. What is the primary purpose of a thermal expansion valve (TXV) in a
refrigeration system?
A) To maintain constant condenser pressure
B) To pump down the system for maintenance
C) To meter refrigerant flow based on evaporator superheat
D) To separate oil from the refrigerant discharge gas
Rationale: The TXV modulates refrigerant flow into the evaporator to
maintain a consistent superheat at the evaporator outlet, preventing
liquid slugging and ensuring proper evaporator performance.
10. Which force acts to open a standard thermostatic expansion valve
(TXV)?
A) Evaporator pressure
B) Spring pressure
C) Sensing bulb pressure
D) Oil pump pressure
Rationale: A TXV operates on a balance of forces. Sensing bulb pressure
acts on top of the diaphragm trying to open the valve, while evaporator
pressure and internal spring pressure act underneath trying to close it.
CERTIFICATION — 200 HIGH-YIELD EXAM QUESTIONS
COMPLETE WITH VERIFIED ANSWERS
1. Which regulation under the Technical Standards and Safety Act, 2000
specifically governs the certification, staffing, and operation of
refrigeration plants in Ontario?
A) Ontario Regulation 213/07
B) Ontario Regulation 219/01
C) Ontario Regulation 223/01
D) Ontario Regulation 847/00
Rationale: Ontario Regulation 219/01 (Operating Engineers) establishes
the requirements for certification, staffing, operation, maintenance,
inspection, and testing of compressor plants and refrigeration plants in
Ontario.
2. What is the primary purpose of CSA B52?
A) To establish energy efficiency ratings for refrigeration equipment
B) To regulate refrigerant pricing across Canada
C) To minimize the risk of personal injury through safety requirements
for refrigeration system design, installation, and operation
D) To certify refrigeration technicians
Rationale: CSA B52 is fundamentally a safety standard focused on
reducing personal injury risk through requirements for design,
installation, inspection, and maintenance of refrigeration systems.
,3. A refrigeration system using R-717 (ammonia) requires what specific
safety classification under ANSI/ASHRAE 34?
A) A1
B) B2L
C) A2
D) B1
Rationale: R-717 (Ammonia) is classified as a B2L refrigerant, indicating
high toxicity and moderate flammability, which dictates specific safety
protocols and equipment requirements.
4. What is the minimum practical operating experience required in a
Class A or B refrigeration plant to challenge the TSSA Class B
certification exam for candidates who have not completed a TSSA-
approved time-reduction program?
A) 720 hours
B) 1,280 hours
C) 1,440 hours
D) 2,160 hours
Rationale: TSSA guidelines require 1,440 hours of practical training in a
Class A or B refrigeration plant for Class B certification. For candidates
who have completed a full-time TSSA-approved time-reduction
program, the requirement is reduced to 1,280 hours.
5. Which personal protective equipment is essential when responding
to an ammonia leak in a refrigeration plant?
A) Dust mask and safety glasses
B) Full-face respirator with ammonia cartridges and chemical-resistant
gloves
,C) Earplugs and hard hat
D) Face shield and cotton gloves
Rationale: Ammonia (R-717) is highly toxic and requires a full-face
respirator with appropriate cartridges and chemical-resistant gloves to
protect against exposure. CSA Z94.4 provides requirements for
respirator selection and use.
6. What is the primary function of a purge unit on a low-pressure
centrifugal chiller?
A) To lubricate the compressor bearings during startup
B) To remove non-condensable gases from the condenser
C) To prevent the evaporator from freezing
D) To recover refrigerant for recharging
Rationale: Non-condensable gases such as air and water vapor can
enter the system and accumulate in the condenser, raising the head
pressure. A purge unit removes them, improving efficiency.
7. What is the primary effect of non-condensable gases (air) in the
condenser?
A) Lowered discharge pressure
B) Decreased compressor amp draw
C) Increased condensing pressure and temperature
D) Increased subcooling
Rationale: Non-condensables occupy volume in the condenser, raising
the head pressure and requiring the compressor to work harder, which
reduces efficiency and increases energy consumption.
8. Which code governs the mechanical safety requirements for the
design, construction, installation, and inspection of refrigeration
, systems in Ontario?
A) CSA B51
B) CSA B52
C) ASHRAE 15
D) CSA B149.1
Rationale: CSA B52: Mechanical Refrigeration Code sets the standards
for safety in refrigeration systems in Ontario. CSA B51 covers boilers and
pressure vessels.
9. What is the primary purpose of a thermal expansion valve (TXV) in a
refrigeration system?
A) To maintain constant condenser pressure
B) To pump down the system for maintenance
C) To meter refrigerant flow based on evaporator superheat
D) To separate oil from the refrigerant discharge gas
Rationale: The TXV modulates refrigerant flow into the evaporator to
maintain a consistent superheat at the evaporator outlet, preventing
liquid slugging and ensuring proper evaporator performance.
10. Which force acts to open a standard thermostatic expansion valve
(TXV)?
A) Evaporator pressure
B) Spring pressure
C) Sensing bulb pressure
D) Oil pump pressure
Rationale: A TXV operates on a balance of forces. Sensing bulb pressure
acts on top of the diaphragm trying to open the valve, while evaporator
pressure and internal spring pressure act underneath trying to close it.
