FDNY Z51 Study Guide Updated 2024-2026with
All 120 Questions and 100% Correct Answer/
FDNY Z51 Exam Updated Version
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 - ANSWER>>lowering the condenser pressure
In most semi hermetic compressors, the suction vapor is used for -
ANSWER>>cools the motor
The amount of refrigerant that flows through the orifices of an economizer is
determined by the - ANSWER>>difference between the high side and the low side
pressure
the instalation of an inline refrigerant cleaning system is advisable - 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: - ANSWER>>a faulty cooling
tower water level controller
when an expansion valve is operating properly, at the end of the evaporator will
contain - ANSWER>>only superheated vapor
a centrifugal water pump is considered to be fully primed when - 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: - 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: - ANSWER>>ammonia
which of the following ashrae refrigerant safety classification is the most toxic -
ANSWER>>b3
which of the following ashrae refrigerant safety classification is the most
flammable - 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 - ANSWER>>r 22 (cooling
medium= glycol or any brine solution)
the primary way of achieving capacity control of a an centrifugal compressor is by:
- ANSWER>>adjustment 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 - 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 - ANSWER>>high suction super heat
the process by which refrigerant is extracted and cleaned for reuse without
requirements for reclamation is called - ANSWER>>recycle
the purpose of wear rings in a centrifugal pump is to - ANSWER>>prevent wearing
of the pump housing and impeller
All 120 Questions and 100% Correct Answer/
FDNY Z51 Exam Updated Version
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 - ANSWER>>lowering the condenser pressure
In most semi hermetic compressors, the suction vapor is used for -
ANSWER>>cools the motor
The amount of refrigerant that flows through the orifices of an economizer is
determined by the - ANSWER>>difference between the high side and the low side
pressure
the instalation of an inline refrigerant cleaning system is advisable - 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: - ANSWER>>a faulty cooling
tower water level controller
when an expansion valve is operating properly, at the end of the evaporator will
contain - ANSWER>>only superheated vapor
a centrifugal water pump is considered to be fully primed when - 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: - 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: - ANSWER>>ammonia
which of the following ashrae refrigerant safety classification is the most toxic -
ANSWER>>b3
which of the following ashrae refrigerant safety classification is the most
flammable - 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 - ANSWER>>r 22 (cooling
medium= glycol or any brine solution)
the primary way of achieving capacity control of a an centrifugal compressor is by:
- ANSWER>>adjustment 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 - 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 - ANSWER>>high suction super heat
the process by which refrigerant is extracted and cleaned for reuse without
requirements for reclamation is called - ANSWER>>recycle
the purpose of wear rings in a centrifugal pump is to - ANSWER>>prevent wearing
of the pump housing and impeller
