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HVAC and Refrigeration Certification Practice Exam
QUESTIONS AND CORRECT VERIFIED ANS WERS
LATEST UPDATE JUST RELEASED THIS YEAR
What is a centrifugal water pump known as when it lifts water?
A lift pump.
What does a TXV maintain constant in a refrigeration system?
Evaporator superheat.
Is a chilled water supply of 55F suitable for human comfort?
Yes, it is within an acceptable range.
What is the function of the packing gland in a centrifugal pump?
To keep air out of the pumps when the impeller housing is under negative pressure.
How is capacity control typically achieved in a reciprocating hermetic compressor?
Through operation of the hot gas bypass valve.
Why is sub-cooling the refrigerant in the condenser important?
To ensure that a pure liquid refrigerant enters the metering device.
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,Page 2 of 29
What could cause a drop in compressor discharge temperature with high suction line
pressure?
Malfunction of a unloader.
What does a low side float valve maintain?
The level of refrigerant in the evaporator.
Which ASHRAE refrigerant safety classification indicates no flammability and lower toxicity?
B1.
What should be present at the end of an evaporator when an expansion valve is operating
properly?
Saturated liquid refrigerant.
What information is not included in a Material Safety Data Sheet (MSDS)?
Cost of the material.
What is the function of the Kingsbury thrust bearing in a steam turbine?
To maintain axial positioning of the rotor shaft.
What indicates a fully primed centrifugal water pump?
The pump is full of liquid.
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, Page 3 of 29
What should be used to prevent tubing collapse at bends in refrigerant lines?
Brazed elbows or annealed tubing.
What affects the efficiency of the refrigerant cycle in a condenser?
The operation of the condenser, particularly the condensing pressure.
What type of heat is removed from the refrigerant in a condenser?
Both sensible and latent heat.
According to the New York City fire code, what is a requirement for refrigerant storage
containers?
Containers must be approved by the US Department of Transportation.
How does a cylinder unloader function?
It controls the clearance volume in the compressor with a solenoid.
What is the primary use of suction vapor in most semi-hermetic compressors?
To cool the motor.
What determines the amount of refrigerant that flows through the orifices of an economizer?
The difference between the high side and low side pressure.
When is the installation of an inline refrigerant cleaning system advisable?
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SUCCESS!
HVAC and Refrigeration Certification Practice Exam
QUESTIONS AND CORRECT VERIFIED ANS WERS
LATEST UPDATE JUST RELEASED THIS YEAR
What is a centrifugal water pump known as when it lifts water?
A lift pump.
What does a TXV maintain constant in a refrigeration system?
Evaporator superheat.
Is a chilled water supply of 55F suitable for human comfort?
Yes, it is within an acceptable range.
What is the function of the packing gland in a centrifugal pump?
To keep air out of the pumps when the impeller housing is under negative pressure.
How is capacity control typically achieved in a reciprocating hermetic compressor?
Through operation of the hot gas bypass valve.
Why is sub-cooling the refrigerant in the condenser important?
To ensure that a pure liquid refrigerant enters the metering device.
1
SUCCESS!
,Page 2 of 29
What could cause a drop in compressor discharge temperature with high suction line
pressure?
Malfunction of a unloader.
What does a low side float valve maintain?
The level of refrigerant in the evaporator.
Which ASHRAE refrigerant safety classification indicates no flammability and lower toxicity?
B1.
What should be present at the end of an evaporator when an expansion valve is operating
properly?
Saturated liquid refrigerant.
What information is not included in a Material Safety Data Sheet (MSDS)?
Cost of the material.
What is the function of the Kingsbury thrust bearing in a steam turbine?
To maintain axial positioning of the rotor shaft.
What indicates a fully primed centrifugal water pump?
The pump is full of liquid.
2
SUCCESS!
, Page 3 of 29
What should be used to prevent tubing collapse at bends in refrigerant lines?
Brazed elbows or annealed tubing.
What affects the efficiency of the refrigerant cycle in a condenser?
The operation of the condenser, particularly the condensing pressure.
What type of heat is removed from the refrigerant in a condenser?
Both sensible and latent heat.
According to the New York City fire code, what is a requirement for refrigerant storage
containers?
Containers must be approved by the US Department of Transportation.
How does a cylinder unloader function?
It controls the clearance volume in the compressor with a solenoid.
What is the primary use of suction vapor in most semi-hermetic compressors?
To cool the motor.
What determines the amount of refrigerant that flows through the orifices of an economizer?
The difference between the high side and low side pressure.
When is the installation of an inline refrigerant cleaning system advisable?
3
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