FDNY Z-51 exam questions with |\ |\ |\ |\ |\
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 condenser pressure
|\ |\ |\ |\ |\
In most semi hermetic compressors, the suction vapor is
|\ |\ |\ |\ |\ |\ |\ |\ |\
used too - CORRECT ANSWERS ✔✔Cool's the motor
|\ |\ |\ |\ |\ |\ |\
The amount of refrigerant that flows through the orifices
|\ |\ |\ |\ |\ |\ |\ |\ |\
of an economizer is determined by the - CORRECT
|\ |\ |\ |\ |\ |\ |\ |\ |\
ANSWERS ✔✔Difference between the high side and the |\ |\ |\ |\ |\ |\ |\ |\
low side pressure
|\ |\
the instalation of an inline refrigerant cleaning system is
|\ |\ |\ |\ |\ |\ |\ |\ |\
advisable - CORRECT ANSWERS ✔✔to remove impurities
|\ |\ |\ |\ |\ |\ |\
from the system |\ |\
a refrigerant engineer verifies that a condenser pump is
|\ |\ |\ |\ |\ |\ |\ |\ |\
cavitating of the following the most likely cause for this
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\
condition is: - CORRECT ANSWERS ✔✔a faulty cooling
|\ |\ |\ |\ |\ |\ |\ |\
tower water level controller
|\ |\ |\
,when an expansion valve is operating properly, at the end
|\ |\ |\ |\ |\ |\ |\ |\ |\
of the evaporator will contain - CORRECT ANSWERS
|\ |\ |\ |\ |\ |\ |\ |\ |\
✔✔only superheated vapor |\ |\
a centrifugal water pump is considered to be fully primed
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\
when - CORRECT ANSWERS ✔✔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
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
ANSWERS ✔✔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 ANSWERS
|\ |\ |\ |\ |\ |\ |\ |\
✔✔ammonia
|\
which of the following ashrae refrigerant safety
|\ |\ |\ |\ |\ |\ |\
classification which is most toxic - CORRECT ANSWERS |\ |\ |\ |\ |\ |\ |\ |\
✔✔B3
, which of the following ashrae refrigerant safety
|\ |\ |\ |\ |\ |\ |\
classification is the most flammable - CORRECT ANSWERS |\ |\ |\ |\ |\ |\ |\
✔✔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 ANSWERS ✔✔r-22
|\ |\ |\ |\ |\ |\ |\ |\
(cooling medium= glycol or any brine solution)
|\ |\ |\ |\ |\ |\
the primary way of achieving capacity control of a an
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\
centrifugal compressor is by: - CORRECT ANSWERS |\ |\ |\ |\ |\ |\ |\
✔✔adjustment of the inlet impeller pre-rotational vanes |\ |\ |\ |\ |\ |\
regarding the functioning of a steam turbine, why is it
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\
advisable to keep moisture in the inlet low as possible -
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
CORRECT ANSWERS ✔✔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 ANSWERS ✔✔high suction
|\ |\ |\ |\ |\ |\ |\ |\
super heat |\
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 condenser pressure
|\ |\ |\ |\ |\
In most semi hermetic compressors, the suction vapor is
|\ |\ |\ |\ |\ |\ |\ |\ |\
used too - CORRECT ANSWERS ✔✔Cool's the motor
|\ |\ |\ |\ |\ |\ |\
The amount of refrigerant that flows through the orifices
|\ |\ |\ |\ |\ |\ |\ |\ |\
of an economizer is determined by the - CORRECT
|\ |\ |\ |\ |\ |\ |\ |\ |\
ANSWERS ✔✔Difference between the high side and the |\ |\ |\ |\ |\ |\ |\ |\
low side pressure
|\ |\
the instalation of an inline refrigerant cleaning system is
|\ |\ |\ |\ |\ |\ |\ |\ |\
advisable - CORRECT ANSWERS ✔✔to remove impurities
|\ |\ |\ |\ |\ |\ |\
from the system |\ |\
a refrigerant engineer verifies that a condenser pump is
|\ |\ |\ |\ |\ |\ |\ |\ |\
cavitating of the following the most likely cause for this
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\
condition is: - CORRECT ANSWERS ✔✔a faulty cooling
|\ |\ |\ |\ |\ |\ |\ |\
tower water level controller
|\ |\ |\
,when an expansion valve is operating properly, at the end
|\ |\ |\ |\ |\ |\ |\ |\ |\
of the evaporator will contain - CORRECT ANSWERS
|\ |\ |\ |\ |\ |\ |\ |\ |\
✔✔only superheated vapor |\ |\
a centrifugal water pump is considered to be fully primed
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\
when - CORRECT ANSWERS ✔✔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
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
ANSWERS ✔✔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 ANSWERS
|\ |\ |\ |\ |\ |\ |\ |\
✔✔ammonia
|\
which of the following ashrae refrigerant safety
|\ |\ |\ |\ |\ |\ |\
classification which is most toxic - CORRECT ANSWERS |\ |\ |\ |\ |\ |\ |\ |\
✔✔B3
, which of the following ashrae refrigerant safety
|\ |\ |\ |\ |\ |\ |\
classification is the most flammable - CORRECT ANSWERS |\ |\ |\ |\ |\ |\ |\
✔✔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 ANSWERS ✔✔r-22
|\ |\ |\ |\ |\ |\ |\ |\
(cooling medium= glycol or any brine solution)
|\ |\ |\ |\ |\ |\
the primary way of achieving capacity control of a an
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\
centrifugal compressor is by: - CORRECT ANSWERS |\ |\ |\ |\ |\ |\ |\
✔✔adjustment of the inlet impeller pre-rotational vanes |\ |\ |\ |\ |\ |\
regarding the functioning of a steam turbine, why is it
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\
advisable to keep moisture in the inlet low as possible -
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
CORRECT ANSWERS ✔✔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 ANSWERS ✔✔high suction
|\ |\ |\ |\ |\ |\ |\ |\
super heat |\
