FDNY Z51 TEST EXAM ,Z51 WRITTEN TEST TAURIS
AND A STUDY GUIDE EXAM 2024 VERSION 170
QUESTIONS WITH DETAILED VERIFIED ANSWERS
AND RATIONALES /A+ GRADE ASSURED
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 ANSWER-lowering the
condenser pressure
In most semi hermetic compressors, the suction vapor is used for - CORRECT ANSWER-cools the motor
The amount of refrigerant that flows through the orifices of an economizer is determined by the -
CORRECT ANSWER-difference between the high side and the low side pressure
the instalation of an inline refrigerant cleaning system is advisable - CORRECT ANSWER-to remove
impurities from the system
a refrigerant engineer verifies that a condenser pump is cavitation of the following the most likely cause
for this condition is: - CORRECT ANSWER-a faulty cooling tower water level controller
when an expansion valve is operating properly, at the end of the evaporator will contain - CORRECT
ANSWER-only superheated vapor
a centrifugal water pump is considered to be fully primed when - CORRECT ANSWER-the pump is full of
liquid
A refrigeration compressor has failed to turn on. the engineer on duty verifies the electrical circuit to the
motor, including all switches and circuit breakers is complete, according to recomended service practice,
the next item to be checked would likely be the: - CORRECT ANSWER-temperature and pressure controls
Refrigerants are characterized by their physical properties including Flashpoint, refrigeration effect and
others, of the refrigerants in commercial and industrial the highest latent heat and refrigerant effect is: -
CORRECT ANSWER-ammonia
, which of the following ashrae refrigerant safety classification is the most toxic - CORRECT ANSWER-b3
which of the following ashrae refrigerant safety classification is the most flammable - CORRECT
ANSWER-a3
in q indirect refrigeration system,of the following, the one that would not be used as a cooling medium
for building spaces being cooled is - CORRECT ANSWER-r 22 (cooling medium= glycol or any brine
solution)
the primary way of achieving capacity control of a an centrifugal compressor is by: - CORRECT
ANSWERadjustment to the inlet impeller pre rotation vanes
regarding the functioning of a steam turbine, why is it advisable to keep moisture in the inlet low as
possible - CORRECT ANSWER-keeps turbine blades wear to minimum
a water chiller is equipped with a reciprocating compressor, a thermostatic expansion valve and a an air
cooled condenser. A restriction in the refrigerant line would result in - CORRECT ANSWER-high suction
super heat
the process by which refrigerant is extracted and cleaned for reuse without requirements for
reclamation is called - CORRECT ANSWER-recycle
the purpose of wear rings in a centrifugal pump is to - CORRECT ANSWER-prevent wearing of the pump
housing and impeller
a centrifugal compressor is in operation with suction pressure is 3 psig and the discharge is 10psi what is
the atmospheric pressure is 14.7 which is the ratio closest to - CORRECT ANSWER-1.39
electrical current us measured in - CORRECT ANSWER-amperage
AND A STUDY GUIDE EXAM 2024 VERSION 170
QUESTIONS WITH DETAILED VERIFIED ANSWERS
AND RATIONALES /A+ GRADE ASSURED
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 ANSWER-lowering the
condenser pressure
In most semi hermetic compressors, the suction vapor is used for - CORRECT ANSWER-cools the motor
The amount of refrigerant that flows through the orifices of an economizer is determined by the -
CORRECT ANSWER-difference between the high side and the low side pressure
the instalation of an inline refrigerant cleaning system is advisable - CORRECT ANSWER-to remove
impurities from the system
a refrigerant engineer verifies that a condenser pump is cavitation of the following the most likely cause
for this condition is: - CORRECT ANSWER-a faulty cooling tower water level controller
when an expansion valve is operating properly, at the end of the evaporator will contain - CORRECT
ANSWER-only superheated vapor
a centrifugal water pump is considered to be fully primed when - CORRECT ANSWER-the pump is full of
liquid
A refrigeration compressor has failed to turn on. the engineer on duty verifies the electrical circuit to the
motor, including all switches and circuit breakers is complete, according to recomended service practice,
the next item to be checked would likely be the: - CORRECT ANSWER-temperature and pressure controls
Refrigerants are characterized by their physical properties including Flashpoint, refrigeration effect and
others, of the refrigerants in commercial and industrial the highest latent heat and refrigerant effect is: -
CORRECT ANSWER-ammonia
, which of the following ashrae refrigerant safety classification is the most toxic - CORRECT ANSWER-b3
which of the following ashrae refrigerant safety classification is the most flammable - CORRECT
ANSWER-a3
in q indirect refrigeration system,of the following, the one that would not be used as a cooling medium
for building spaces being cooled is - CORRECT ANSWER-r 22 (cooling medium= glycol or any brine
solution)
the primary way of achieving capacity control of a an centrifugal compressor is by: - CORRECT
ANSWERadjustment to the inlet impeller pre rotation vanes
regarding the functioning of a steam turbine, why is it advisable to keep moisture in the inlet low as
possible - CORRECT ANSWER-keeps turbine blades wear to minimum
a water chiller is equipped with a reciprocating compressor, a thermostatic expansion valve and a an air
cooled condenser. A restriction in the refrigerant line would result in - CORRECT ANSWER-high suction
super heat
the process by which refrigerant is extracted and cleaned for reuse without requirements for
reclamation is called - CORRECT ANSWER-recycle
the purpose of wear rings in a centrifugal pump is to - CORRECT ANSWER-prevent wearing of the pump
housing and impeller
a centrifugal compressor is in operation with suction pressure is 3 psig and the discharge is 10psi what is
the atmospheric pressure is 14.7 which is the ratio closest to - CORRECT ANSWER-1.39
electrical current us measured in - CORRECT ANSWER-amperage
