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FDNY Z51 RMO QUESTIONS ANSWERED
VERIFIED GRADED A+ ALREADY PASSED!
Question 1: 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
Question 2: In most semi hermetic compressors, the suction
vapor is used for
CORRECT ANSWER : cools the motor
Question 3: 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
Question 4: The instalation of an inline refrigerant cleaning
system is advisable
CORRECT ANSWER : to remove impurities from the system
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Question 5: 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
Question 6: When an expansion valve is operating properly, at
the end of the evaporator will contain
CORRECT ANSWER : only superheated vapor
Question 7: A centrifugal water pump is considered to be fully
primed when
CORRECT ANSWER: the pump is full of liquid
Question 8: 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
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Question 9: 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
Question 10: Which of the following ashrae refrigerant safety
classification is the most toxic
CORRECT ANSWER : b3
Question 11: Which of the following ashrae refrigerant safety
classification is the most flammable
CORRECT ANSWER : a3
Question 12: 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)
Question 13: The primary way of achieving capacity control of a
an centrifugal compressor is by:
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CORRECT ANSWER : adjustment to the inlet impeller pre
rotation vanes
Question 14: 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
Question 15: 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
Question 16: The process by which refrigerant is extracted and
cleaned for reuse without requirements for reclamation is called
CORRECT ANSWER : recycle
Question 17: The purpose of wear rings in a centrifugal pump is
to
CORRECT ANSWER : prevent wearing of the pump housing
and impeller
