Z51 Refrigeration Test Newest Test | All Questions And Correct Answers |
Graded A+ | Verified Answers | Study This One!
Efficiency of the refrigerant cycle is affected by the operations of the condenser. Of the following, a
more efficient centrifugal compressor operation results from: - (CORRECT ANSWER)Lowering the
condensing pressure
The heat removed from the refrigerant in a condenser is: - (CORRECT ANSWER)Sensible and latent heat
The refrigerant unit that you have been assigned to is being taken out of service for a major repair. You
have been assigned to withdraw refrigerant for storage in suitable containers. According to the NYC Fire
Code, you must ensure that the containers: - (CORRECT ANSWER)Are approved by the US Dept. of
Transportation
Which of the following best describes how the cylinder unloader works? - (CORRECT ANSWER)Keep in
the suction valve opened while the compressor is in the return stroke
In most semi-hermetic compressors, the suction vapor is used to: - (CORRECT ANSWER)Cool the motor
The amount of refrigerant that flows through the orifices of an economizer is determined by the: -
(CORRECT ANSWER)Differences between the high side and low side pressure
The installation of an inline refrigerant cleaning system is advisable: - (CORRECT ANSWER)To remove
impurities from the system
The type of refrigerant system that is least likely to leak refrigerant into the building space that are being
cooled: - (CORRECT ANSWER)Indirect system
The suction pressure of a reciprocating compressor is 65 PSIG. The discharge pressure of this
compressor is 120 PSIG. The atmospheric is 14.7 PSI. The compression ratio for the given condition is
closest to: - (CORRECT ANSWER)1.69
A superheated vapor is: - (CORRECT ANSWER)Dry vapor above the saturation temperature
1
,A refrigerant engineer verifies that a condenser water pump is cavitating. Of the following, the most
likely cause for this condition is: - (CORRECT ANSWER)A faulty cooling tower water level controller
A centrifugal water pump is known as a lift pump when the: - (CORRECT ANSWER)The water supply to
the pump suction inlet is below the pump level
A TXV is used to maintain constant: - (CORRECT ANSWER)Evaporator superheat
The chilled water supply to the building is 55 deg F. If the chiller is being used for human comfort, should
you be concerned about this, and why? - (CORRECT ANSWER)Yes, this temp is too high for human
comfort purposes
The packing gland of a centrifugal pump serves to: - (CORRECT ANSWER)The drip part of the packing
gland gives evidence that there is water in the pump
Capacity control of reciprocating hermetic compressor is typically achieved through: - (CORRECT
ANSWER)Operation of the hot gas bypass valve
The most important reason to sub-cool the refrigerant in the condenser is to ensure that: - (CORRECT
ANSWER)A pure liquid refrigerant will enter the metering device
A refrigeration engineer is logging readings from a reciprocating system. Compressor discharge
temperature have dropped significantly and the suction line pressure is high. Which of the following
that may be causing this set of condition? - (CORRECT ANSWER)An expansion valve that is open too
wide
A low side float valve is used to maintain: - (CORRECT ANSWER)The level of the refrigerant in the
evaporator
2
, Regarding fire safety, which ASHRAE refrigerant safety classification indicates no flammability and lower
toxicity? - (CORRECT ANSWER)A1
When an expansion valve is operating properly, at the end of the evaporator will contain: - (CORRECT
ANSWER)Only superheated vapor
What information is not contained in a Material Safety Data Sheet? - (CORRECT ANSWER)Cost of the
material
In a steam turbine, what is the function of the Kingsbury thrust bearing? - (CORRECT ANSWER)Maintain
axial positioning of the rotor shaft
A centrifugal water pump is considered to the fully primed when? - (CORRECT ANSWER)The pump is full
of liquid
Copper tubing refrigerant lines must be installed for a new system. It is a well known service practice
that tubing collapses at bends that must be made, the refrigerant engineer should use? - (CORRECT
ANSWER)Level type tubing bender
A reciprocating compressor is making a knocking sound during operation. If the refrigerant worn parts
are not causing the knocking, what probably the cause? - (CORRECT ANSWER)Slugging of the liquid
refrigerant
In order for a refrigerant to become superheated, it must be heated in a section of the low side
refrigerant line: - (CORRECT ANSWER)Where no liquid refrigerant is present
All liquid has been recovered from a system to be overhauled, the system: - (CORRECT ANSWER)Should
not be opened until all vapor has been recovered
3
Graded A+ | Verified Answers | Study This One!
Efficiency of the refrigerant cycle is affected by the operations of the condenser. Of the following, a
more efficient centrifugal compressor operation results from: - (CORRECT ANSWER)Lowering the
condensing pressure
The heat removed from the refrigerant in a condenser is: - (CORRECT ANSWER)Sensible and latent heat
The refrigerant unit that you have been assigned to is being taken out of service for a major repair. You
have been assigned to withdraw refrigerant for storage in suitable containers. According to the NYC Fire
Code, you must ensure that the containers: - (CORRECT ANSWER)Are approved by the US Dept. of
Transportation
Which of the following best describes how the cylinder unloader works? - (CORRECT ANSWER)Keep in
the suction valve opened while the compressor is in the return stroke
In most semi-hermetic compressors, the suction vapor is used to: - (CORRECT ANSWER)Cool the motor
The amount of refrigerant that flows through the orifices of an economizer is determined by the: -
(CORRECT ANSWER)Differences between the high side and low side pressure
The installation of an inline refrigerant cleaning system is advisable: - (CORRECT ANSWER)To remove
impurities from the system
The type of refrigerant system that is least likely to leak refrigerant into the building space that are being
cooled: - (CORRECT ANSWER)Indirect system
The suction pressure of a reciprocating compressor is 65 PSIG. The discharge pressure of this
compressor is 120 PSIG. The atmospheric is 14.7 PSI. The compression ratio for the given condition is
closest to: - (CORRECT ANSWER)1.69
A superheated vapor is: - (CORRECT ANSWER)Dry vapor above the saturation temperature
1
,A refrigerant engineer verifies that a condenser water pump is cavitating. Of the following, the most
likely cause for this condition is: - (CORRECT ANSWER)A faulty cooling tower water level controller
A centrifugal water pump is known as a lift pump when the: - (CORRECT ANSWER)The water supply to
the pump suction inlet is below the pump level
A TXV is used to maintain constant: - (CORRECT ANSWER)Evaporator superheat
The chilled water supply to the building is 55 deg F. If the chiller is being used for human comfort, should
you be concerned about this, and why? - (CORRECT ANSWER)Yes, this temp is too high for human
comfort purposes
The packing gland of a centrifugal pump serves to: - (CORRECT ANSWER)The drip part of the packing
gland gives evidence that there is water in the pump
Capacity control of reciprocating hermetic compressor is typically achieved through: - (CORRECT
ANSWER)Operation of the hot gas bypass valve
The most important reason to sub-cool the refrigerant in the condenser is to ensure that: - (CORRECT
ANSWER)A pure liquid refrigerant will enter the metering device
A refrigeration engineer is logging readings from a reciprocating system. Compressor discharge
temperature have dropped significantly and the suction line pressure is high. Which of the following
that may be causing this set of condition? - (CORRECT ANSWER)An expansion valve that is open too
wide
A low side float valve is used to maintain: - (CORRECT ANSWER)The level of the refrigerant in the
evaporator
2
, Regarding fire safety, which ASHRAE refrigerant safety classification indicates no flammability and lower
toxicity? - (CORRECT ANSWER)A1
When an expansion valve is operating properly, at the end of the evaporator will contain: - (CORRECT
ANSWER)Only superheated vapor
What information is not contained in a Material Safety Data Sheet? - (CORRECT ANSWER)Cost of the
material
In a steam turbine, what is the function of the Kingsbury thrust bearing? - (CORRECT ANSWER)Maintain
axial positioning of the rotor shaft
A centrifugal water pump is considered to the fully primed when? - (CORRECT ANSWER)The pump is full
of liquid
Copper tubing refrigerant lines must be installed for a new system. It is a well known service practice
that tubing collapses at bends that must be made, the refrigerant engineer should use? - (CORRECT
ANSWER)Level type tubing bender
A reciprocating compressor is making a knocking sound during operation. If the refrigerant worn parts
are not causing the knocking, what probably the cause? - (CORRECT ANSWER)Slugging of the liquid
refrigerant
In order for a refrigerant to become superheated, it must be heated in a section of the low side
refrigerant line: - (CORRECT ANSWER)Where no liquid refrigerant is present
All liquid has been recovered from a system to be overhauled, the system: - (CORRECT ANSWER)Should
not be opened until all vapor has been recovered
3
