5/22/25, 10:58 PM FDNY Z51 WRITTEN EXAM ACTUAL EXAM 2 VERSIONS (VERSION A AND B) COMPLETE 400 QUESTIONS WITH DETAILED…
FDNY Z51 WRITTEN EXAM ACTUAL EXAM 2
VERSIONS (VERSION A AND B) COMPLETE 400
QUESTIONS WITH DETAILED VERIFIED
ANSWERS/
A refrigerant engineer Water leaks through the mechanical seals
verifies that a chilled water
pump is cavitating. of the
following the most likely
cause for this condition is:
There is a decrease in the Leaking suction valve
efficiency of a reciprocating
compressor. this most likely
caused by:
The suction and discharge Discharge valves on top of the valve plate and suction valve
valve of the below
reciprocating compressor are
mounted as follows:
You are the engineer Put on an additional surface condenser pump and lower the
running a 2000-ton chilled water set point
(steam-driven turbine)
centrifugal
refrigeration system, a
refrigeration system supplies
chilled water to a college
campus with multiple
buildings. while making your
rounds you notice that the
discharge
1/36
,5/22/25, 10:58 PM FDNY Z51 WRITTEN EXAM ACTUAL EXAM 2 VERSIONS (VERSION A AND B) COMPLETE 400 QUESTIONS WITH DETAILED…
pressure of your condenser
water pumps is significantly
lower than normal. which
of the following action
would you avoid taking:
A water pump is discharge 40 psi
against head 92 feet of
water, this is approximately
to a
pressure of:
Which of the following will Vacuum pump
connect to the middle port
on a gauge manifold?
The most important reason To contain the compressor pulsation noise
for installing a muffler in a
reciprocating refrigerant
machine is:
Of the following, the Will have both the compressor and motor enclosed is gas tight
statement that most housing
accurately characterize a
hermetic
compressor is that it:
In the picture the valve is in The valve is crack open
what position (45 degree
angle to the left)
What is the order of King valve, filter drier, solenoid valve, sight glass
components on the liquid
line of a reciprocating
system from the
condenser to the TEV?
A high-side float valve is used Constant level of refrigerant in the evaporator
to maintain:
… 2/36
,5/22/25, 10:58 PM FDNY Z51 WRITTEN EXAM ACTUAL EXAM 2 VERSIONS (VERSION A AND B) COMPLETE 400 QUESTIONS WITH DETAILED…
Ninety degree reducing elbow, pump suction, pump
Picture of pump:
casing, pump discharge, check valve
Picture of compressor: Oil charging port allows for the addition and removal of oil from
the compressor
A facility has failed to Increase in the condenser pressure
maintain water
treatement to a
refrigerant system:
Which of these Centrifugal
compressors is not a
positive displacement type
compressor?
Where is emergency power Data centers
not required according to
code?
What is the most widely EPA
used regulation book by
operating engineers is?
What type of refrigerant do Propane
you need FDNY approval
for?
Centrifugal pressure is Speed of motor
determined by?
A single phase 208 VAC Ground
circuit has 2 hot wires and
the third is?
Liquid refrigerant that has Low pressure saturated liquid
passed through a meter
device is a ?
With a 75 degree dry bulb and Very high
a 73 degree wet bulb the
relative humidity is?
After recovering liquid Recover vapor
refrigerant from a centrifugal
chiller the next step is to?
Where is the muffler located? Between the compressor and the condenser
… 3/36
, 5/22/25, 10:58 PM FDNY Z51 WRITTEN EXAM ACTUAL EXAM 2 VERSIONS (VERSION A AND B) COMPLETE 400 QUESTIONS WITH DETAILED…
What is not required to be Compressors
serviced annually?
What is the advantage of a Better heat transfer
shell and tube condenser,
as opposed to a shell and
coil condenser?
Fusible plugs on a condenser: The melting point is marked on it
How much extra refrigerant 330 lbs.
can be stored in a machine
room?
What is used on an outside Resistor
pipe to prevent it from
freezing?
Of the following centrifugal High tonnage, low pressure machines
chillers are best
characterized as?
As an engineer you notice Evaporator will flood
pressure drops across the
evaporator. you check
and notice the external
equalizer line is
disconnected. what will occur
in the evaporator?
When entering phase 2 The elevator operator is the only person that could control the
fireman's service, what elevator
statement is correct?
A FDNY permit is required to Use of oxygen and flammable gas
conduct hot works for?
FDNY is most concerned A3
with which ASHRAE
refrigerant classification?
How long must a fire alarm 3 years
log book be kept?
What is the minimum Once per shift
requirement an engineer
… 4/36
FDNY Z51 WRITTEN EXAM ACTUAL EXAM 2
VERSIONS (VERSION A AND B) COMPLETE 400
QUESTIONS WITH DETAILED VERIFIED
ANSWERS/
A refrigerant engineer Water leaks through the mechanical seals
verifies that a chilled water
pump is cavitating. of the
following the most likely
cause for this condition is:
There is a decrease in the Leaking suction valve
efficiency of a reciprocating
compressor. this most likely
caused by:
The suction and discharge Discharge valves on top of the valve plate and suction valve
valve of the below
reciprocating compressor are
mounted as follows:
You are the engineer Put on an additional surface condenser pump and lower the
running a 2000-ton chilled water set point
(steam-driven turbine)
centrifugal
refrigeration system, a
refrigeration system supplies
chilled water to a college
campus with multiple
buildings. while making your
rounds you notice that the
discharge
1/36
,5/22/25, 10:58 PM FDNY Z51 WRITTEN EXAM ACTUAL EXAM 2 VERSIONS (VERSION A AND B) COMPLETE 400 QUESTIONS WITH DETAILED…
pressure of your condenser
water pumps is significantly
lower than normal. which
of the following action
would you avoid taking:
A water pump is discharge 40 psi
against head 92 feet of
water, this is approximately
to a
pressure of:
Which of the following will Vacuum pump
connect to the middle port
on a gauge manifold?
The most important reason To contain the compressor pulsation noise
for installing a muffler in a
reciprocating refrigerant
machine is:
Of the following, the Will have both the compressor and motor enclosed is gas tight
statement that most housing
accurately characterize a
hermetic
compressor is that it:
In the picture the valve is in The valve is crack open
what position (45 degree
angle to the left)
What is the order of King valve, filter drier, solenoid valve, sight glass
components on the liquid
line of a reciprocating
system from the
condenser to the TEV?
A high-side float valve is used Constant level of refrigerant in the evaporator
to maintain:
… 2/36
,5/22/25, 10:58 PM FDNY Z51 WRITTEN EXAM ACTUAL EXAM 2 VERSIONS (VERSION A AND B) COMPLETE 400 QUESTIONS WITH DETAILED…
Ninety degree reducing elbow, pump suction, pump
Picture of pump:
casing, pump discharge, check valve
Picture of compressor: Oil charging port allows for the addition and removal of oil from
the compressor
A facility has failed to Increase in the condenser pressure
maintain water
treatement to a
refrigerant system:
Which of these Centrifugal
compressors is not a
positive displacement type
compressor?
Where is emergency power Data centers
not required according to
code?
What is the most widely EPA
used regulation book by
operating engineers is?
What type of refrigerant do Propane
you need FDNY approval
for?
Centrifugal pressure is Speed of motor
determined by?
A single phase 208 VAC Ground
circuit has 2 hot wires and
the third is?
Liquid refrigerant that has Low pressure saturated liquid
passed through a meter
device is a ?
With a 75 degree dry bulb and Very high
a 73 degree wet bulb the
relative humidity is?
After recovering liquid Recover vapor
refrigerant from a centrifugal
chiller the next step is to?
Where is the muffler located? Between the compressor and the condenser
… 3/36
, 5/22/25, 10:58 PM FDNY Z51 WRITTEN EXAM ACTUAL EXAM 2 VERSIONS (VERSION A AND B) COMPLETE 400 QUESTIONS WITH DETAILED…
What is not required to be Compressors
serviced annually?
What is the advantage of a Better heat transfer
shell and tube condenser,
as opposed to a shell and
coil condenser?
Fusible plugs on a condenser: The melting point is marked on it
How much extra refrigerant 330 lbs.
can be stored in a machine
room?
What is used on an outside Resistor
pipe to prevent it from
freezing?
Of the following centrifugal High tonnage, low pressure machines
chillers are best
characterized as?
As an engineer you notice Evaporator will flood
pressure drops across the
evaporator. you check
and notice the external
equalizer line is
disconnected. what will occur
in the evaporator?
When entering phase 2 The elevator operator is the only person that could control the
fireman's service, what elevator
statement is correct?
A FDNY permit is required to Use of oxygen and flammable gas
conduct hot works for?
FDNY is most concerned A3
with which ASHRAE
refrigerant classification?
How long must a fire alarm 3 years
log book be kept?
What is the minimum Once per shift
requirement an engineer
… 4/36
