FDNY Z51 RMO FINAL PAPER

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FDNY Z51 RMO FINAL PAPER

QUESTIONS WITH SOLUT IONS

GRADED A+

Question :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 :In most semi hermetic compressors, the suction

vapor is used for CORRECT ANSWER: :cools the motor

Question :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

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Question :the instalation of an inline refrigerant cleaning

system is advisable CORRECT ANSWER: :to remove impurities from the system

Question :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 :when an expansion valve is operating properly,

at the end of the evaporator will contain CORRECT ANSWER: :only superheated vapor

Question :a centrifugal water pump is considered to be

fully primed when CORRECT ANSWER: :the pump is full of liquid

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Question :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

Question :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 :which of the following ashrae refrigerant safety

classification is the most toxic CORRECT ANSWER: :b3

Question :which of the following ashrae refrigerant safety

classification is the most flammable CORRECT ANSWER: :a3

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Question :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 :the primary way of achieving capacity control

of a an centrifugal compressor is by:

CORRECT ANSWER: :adjustment to the inlet impeller pre rotation vanes

Question :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 :a water chiller is equipped with a reciprocating

compressor, a thermostatic expansion valve and a an air