FDNY Z-51 EXAM STUDY GUIDE QUESTIONS AND ANSWERS (100% CORRECT ANSWERS)

FDNY Z-51/AND STUDY GUIDE EXAM NEWEST 2025 TEST BANK| COMPLETE 550 QUESTIONS AND
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FDNY Z-51EXAM STUDY GUIDE QUESTIONS
AND ANSWERS (100% CORRECT
ANSWERS) ALREADY GRADED A+|FDNY
Z51 WRITTEN EXAM TEST BANK |BRAND
NEW!!
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 too
Correct Answer
Cool's 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




Page 1 of 24

, FDNY Z-51/AND STUDY GUIDE EXAM NEWEST 2025 TEST BANK| COMPLETE 550 QUESTIONS AND
VERIFIED ANSWERS (100% CORRECT ANSWERS) ALREADY GRADED A+|FDNY Z51 WRITTEN EXAM
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Question 5
a refrigerant engineer verifies that a condenser pump is cavitating 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



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




Page 2 of 24

, FDNY Z-51/AND STUDY GUIDE EXAM NEWEST 2025 TEST BANK| COMPLETE 550 QUESTIONS AND
VERIFIED ANSWERS (100% CORRECT ANSWERS) ALREADY GRADED A+|FDNY Z51 WRITTEN EXAM
TEST BANK |BRAND NEW!!



Question 10
which of the following ashrae refrigerant safety classification which is 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:
Correct Answer
adjustment of the inlet impeller pre-rotational 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




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