FDNY written z51 questions with correct |\ |\ |\ |\ |\ |\
answers
The efficiency of the refrigerant cycle is affected by the operation
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\
of the condenser. of the following. a more efficient centrifugal
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
compressor operation results from: - CORRECT ANSWERS |\ |\ |\ |\ |\ |\ |\
✔✔Lowering the condensing pressure |\ |\ |\
The heat removed from the refrigerant in a condenser is: -
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
CORRECT ANSWERS ✔✔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 new York city fire code, you must ensure that
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
the containers: - CORRECT ANSWERS ✔✔Are approved by the US
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\
department of transportation |\ |\
Which of the following best describes how the cylinder unloader
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\
work? - CORRECT ANSWERS ✔✔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 ANSWERS ✔✔Cool the motor
|\ |\ |\ |\ |\ |\
,The amount of refrigerant that flows through the orifices of a
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
economizer is determined by the: - CORRECT ANSWERS |\ |\ |\ |\ |\ |\ |\ |\
✔✔Difference between the high side and load side pressure |\ |\ |\ |\ |\ |\ |\ |\
The installation of an inline refrigerant cleaning system is
|\ |\ |\ |\ |\ |\ |\ |\ |\
advisable: - CORRECT ANSWERS ✔✔To remove impurities from
|\ |\ |\ |\ |\ |\ |\ |\
the system |\
The type of refrigerant system that is least likely to leak
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
refrigerant into the building space that are cooled - CORRECT
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\
ANSWERS ✔✔The indirect system |\ |\ |\
The suction pressure of a reciprocating compressor is 65PSIG. the
|\ |\ |\ |\ |\ |\ |\ |\ |\
discharge pressure of this compressor is 120PSIG. the
|\ |\ |\ |\ |\ |\ |\ |\ |\
atmospheric is 14.7 PSI. the compression ratio for the given |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
condition is closet to: - CORRECT ANSWERS ✔✔1.69
|\ |\ |\ |\ |\ |\ |\
A super heated vapor is a ? - CORRECT ANSWERS ✔✔Dry vapor
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
above the saturation temperature
|\ |\ |\
A refrigerant engineer verifies that a condenser water pump is
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\
cavitating. of the following the most likely cause for this condition
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\
is: - CORRECT ANSWERS ✔✔A faulty cooling tower water level
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
controller
A centrifugal water pump is known as a lift pump when the: -
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
CORRECT ANSWERS ✔✔The water supply to the pump suction
|\ |\ |\ |\ |\ |\ |\ |\ |\
inlet is below the pump level
|\ |\ |\ |\ |\
,A TXV is used to maintain constant: - CORRECT ANSWERS
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\
✔✔Evaporator superheat |\
The chilled water supply to the building is 55F. if the chiller is
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
being used for human comfort, should you be concerned about
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\
this , and why? - CORRECT ANSWERS ✔✔Yes, this temperature is
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
too high for human comfort purpose
|\ |\ |\ |\ |\
The packing gland of a centrifugal pump serves to: - CORRECT
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
ANSWERS ✔✔The drip part of the packing gland gives evidence
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\
that there is water in the pump
|\ |\ |\ |\ |\ |\
Capacity control of a reciprocating hermetic compressor is
|\ |\ |\ |\ |\ |\ |\ |\
typically achieved through - CORRECT ANSWERS ✔✔Operation of
|\ |\ |\ |\ |\ |\ |\ |\
the hot gas bypass valve
|\ |\ |\ |\
The most important reason to sub-cool the refrigerant in the
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\
condenser is to ensure that: - CORRECT ANSWERS ✔✔A pure |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
liquid refrigerant will enter the metering device
|\ |\ |\ |\ |\ |\
A refrigeration engineer is logging reading 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
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
ANSWERS ✔✔An expansion valve that is open to wide |\ |\ |\ |\ |\ |\ |\ |\
A low side float valve is used to maintain: - CORRECT ANSWERS
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
✔✔The level of the refrigerant in the evaporator
|\ |\ |\ |\ |\ |\ |\
, Regarding fire safety, which ASHARE refrigerant safety
|\ |\ |\ |\ |\ |\ |\
classification indicates no flammability and lower the toxicity? - |\ |\ |\ |\ |\ |\ |\ |\ |\
CORRECT ANSWERS ✔✔A1 |\ |\
When an expansion valve is operating properly, at the end of the
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
evaporator will contain: - CORRECT ANSWERS ✔✔Only |\ |\ |\ |\ |\ |\ |\
superheated vapor |\
What information is not contained in a material safety data
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\
sheet-MSDS? - CORRECT ANSWERS ✔✔Cost of material |\ |\ |\ |\ |\ |\
In a steam turbine, what is the function of the kingsbury thrust
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
bearing - CORRECT ANSWERS ✔✔Maintain axial positioning of the
|\ |\ |\ |\ |\ |\ |\ |\
rotor shaft
|\ |\
A centrifugal water pump is considered to be fully primed when -
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
CORRECT ANSWERS ✔✔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 ANSWERS ✔✔Lever type tubing bender
|\ |\ |\ |\ |\ |\ |\
A reciprocating compressor is making a knocking sound during
|\ |\ |\ |\ |\ |\ |\ |\ |\
operation. if the refrigerant worn parts are not causing the
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\
knocking, what is probably the cause - CORRECT ANSWERS
|\ |\ |\ |\ |\ |\ |\ |\ |\
✔✔The slugging of the liquid refrigerant
|\ |\ |\ |\ |\
answers
The efficiency of the refrigerant cycle is affected by the operation
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\
of the condenser. of the following. a more efficient centrifugal
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
compressor operation results from: - CORRECT ANSWERS |\ |\ |\ |\ |\ |\ |\
✔✔Lowering the condensing pressure |\ |\ |\
The heat removed from the refrigerant in a condenser is: -
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
CORRECT ANSWERS ✔✔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 new York city fire code, you must ensure that
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
the containers: - CORRECT ANSWERS ✔✔Are approved by the US
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\
department of transportation |\ |\
Which of the following best describes how the cylinder unloader
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\
work? - CORRECT ANSWERS ✔✔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 ANSWERS ✔✔Cool the motor
|\ |\ |\ |\ |\ |\
,The amount of refrigerant that flows through the orifices of a
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
economizer is determined by the: - CORRECT ANSWERS |\ |\ |\ |\ |\ |\ |\ |\
✔✔Difference between the high side and load side pressure |\ |\ |\ |\ |\ |\ |\ |\
The installation of an inline refrigerant cleaning system is
|\ |\ |\ |\ |\ |\ |\ |\ |\
advisable: - CORRECT ANSWERS ✔✔To remove impurities from
|\ |\ |\ |\ |\ |\ |\ |\
the system |\
The type of refrigerant system that is least likely to leak
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
refrigerant into the building space that are cooled - CORRECT
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\
ANSWERS ✔✔The indirect system |\ |\ |\
The suction pressure of a reciprocating compressor is 65PSIG. the
|\ |\ |\ |\ |\ |\ |\ |\ |\
discharge pressure of this compressor is 120PSIG. the
|\ |\ |\ |\ |\ |\ |\ |\ |\
atmospheric is 14.7 PSI. the compression ratio for the given |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
condition is closet to: - CORRECT ANSWERS ✔✔1.69
|\ |\ |\ |\ |\ |\ |\
A super heated vapor is a ? - CORRECT ANSWERS ✔✔Dry vapor
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
above the saturation temperature
|\ |\ |\
A refrigerant engineer verifies that a condenser water pump is
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\
cavitating. of the following the most likely cause for this condition
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\
is: - CORRECT ANSWERS ✔✔A faulty cooling tower water level
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
controller
A centrifugal water pump is known as a lift pump when the: -
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
CORRECT ANSWERS ✔✔The water supply to the pump suction
|\ |\ |\ |\ |\ |\ |\ |\ |\
inlet is below the pump level
|\ |\ |\ |\ |\
,A TXV is used to maintain constant: - CORRECT ANSWERS
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\
✔✔Evaporator superheat |\
The chilled water supply to the building is 55F. if the chiller is
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
being used for human comfort, should you be concerned about
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\
this , and why? - CORRECT ANSWERS ✔✔Yes, this temperature is
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
too high for human comfort purpose
|\ |\ |\ |\ |\
The packing gland of a centrifugal pump serves to: - CORRECT
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
ANSWERS ✔✔The drip part of the packing gland gives evidence
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\
that there is water in the pump
|\ |\ |\ |\ |\ |\
Capacity control of a reciprocating hermetic compressor is
|\ |\ |\ |\ |\ |\ |\ |\
typically achieved through - CORRECT ANSWERS ✔✔Operation of
|\ |\ |\ |\ |\ |\ |\ |\
the hot gas bypass valve
|\ |\ |\ |\
The most important reason to sub-cool the refrigerant in the
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\
condenser is to ensure that: - CORRECT ANSWERS ✔✔A pure |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
liquid refrigerant will enter the metering device
|\ |\ |\ |\ |\ |\
A refrigeration engineer is logging reading 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
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
ANSWERS ✔✔An expansion valve that is open to wide |\ |\ |\ |\ |\ |\ |\ |\
A low side float valve is used to maintain: - CORRECT ANSWERS
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
✔✔The level of the refrigerant in the evaporator
|\ |\ |\ |\ |\ |\ |\
, Regarding fire safety, which ASHARE refrigerant safety
|\ |\ |\ |\ |\ |\ |\
classification indicates no flammability and lower the toxicity? - |\ |\ |\ |\ |\ |\ |\ |\ |\
CORRECT ANSWERS ✔✔A1 |\ |\
When an expansion valve is operating properly, at the end of the
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
evaporator will contain: - CORRECT ANSWERS ✔✔Only |\ |\ |\ |\ |\ |\ |\
superheated vapor |\
What information is not contained in a material safety data
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\
sheet-MSDS? - CORRECT ANSWERS ✔✔Cost of material |\ |\ |\ |\ |\ |\
In a steam turbine, what is the function of the kingsbury thrust
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
bearing - CORRECT ANSWERS ✔✔Maintain axial positioning of the
|\ |\ |\ |\ |\ |\ |\ |\
rotor shaft
|\ |\
A centrifugal water pump is considered to be fully primed when -
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
CORRECT ANSWERS ✔✔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 ANSWERS ✔✔Lever type tubing bender
|\ |\ |\ |\ |\ |\ |\
A reciprocating compressor is making a knocking sound during
|\ |\ |\ |\ |\ |\ |\ |\ |\
operation. if the refrigerant worn parts are not causing the
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\
knocking, what is probably the cause - CORRECT ANSWERS
|\ |\ |\ |\ |\ |\ |\ |\ |\
✔✔The slugging of the liquid refrigerant
|\ |\ |\ |\ |\
