1|Page
Z-51 REFRIGERATION EXAM LATEST 2024- 2025
WITH UPDATED QUESTIONS AND ANSWERS
(ALREADY GRADED A+)
Information about the physical and chemical properties of a
hazardous material can be found in: - ANSWER-Material Safety
Data Sheet
What is the function of the turbine auxiliary oil pump? - ANSWER-
Establish oil pressure during turbine start up
The rupture disc for a low pressure centrifugal refrigeration
machine is normally located on the: - ANSWER-Compressor
suction
What is the primary reason ribbed metal piping is used for
electrical wires connected to the refrigeration system shown
below? - ANSWER-It allows for flexibility and accounts for
vibrations
,2|Page
A multi cylinder reciprocating compressor uses cylinder unloaders
to regulate capacity, what would not occur if some of the
unloaders fail to operate when needed? - ANSWER-The chill
water temperature will increase
As shown in the picture below, the suction gauge of a condenser
water pump reads 55 PSI. The pipe supplying the pump is 75 feet
long and 12 inches in diameter. Approximately, how many gallons
of water do you expect to obtain if the pipe is drained completely?
- ANSWER-440
A water chiller system uses refrigerant R-123. A leak in the
evaporator shell may result in: - ANSWER-A higher than normal
high side pressure
Capacitors are used on refrigeration motors. Of the following, the
function of these devices is to: - ANSWER-Store electrical
chargers during starting and running the motor
Of the following, centrifugal refrigerant machine is best
characterized by: - ANSWER-A high volume, low pressure
machine
,3|Page
Which of the following ASHRAE refrigerant safety classifications
is the most flammable? - ANSWER-A3
Which of the following correctly describes the object in the picture
below? - ANSWER-Standpipe hose outlet, to put out fires in case
of emergency
Modern compressors usually seal the rotating shaft as it exits the
compressor housing a spring - ANSWER-Metal or carbon
The British Thermal Unit (BTU) is the measurement of heat of
energy. If 10 BTU's are transferred to 10 pounds of water, the
water temperature increase will be closest to: - ANSWER-1 deg F
A reciprocating compressor cylinder has a 10 inches bore and 14
inches stroke. The volume of the refrigerant , in cubic inches, will
be closer to: - ANSWER-1099
, 4|Page
An electrically operated control requires 24 volts to operate. To
change the available 110 volts to 24 volts - ANSWER-
Transformer
In an indirect refrigeration system, of the following, the one that
would not be used as a cooling medium for the building spaces
being cooled is: - ANSWER-R-22
On a steam turbine, what would cause the atmospheric valve to
open? - ANSWER-All answers (low vacuum in the surface
condenser, leaking tubes in the surface condenser, dirty tubes in
the surface condenser)
You are the engineer running a 2000-ton (steam driven turbine)
centrifugal rerigeration system, a refrigeration system supplies
chilled water to a college campus with multiple buildings. Making
your rounds, you notice that the condenser water pump #1 is
making a lot of noise, the discharger guage reading of the
condenser water pump is fluctuating drastically, and motor of the
condenser pump #1 is running very hot. Which of the following
would you take: - ANSWER-Turn on pump #2, shut off pump #1,
and troubleshoot pump #1
Z-51 REFRIGERATION EXAM LATEST 2024- 2025
WITH UPDATED QUESTIONS AND ANSWERS
(ALREADY GRADED A+)
Information about the physical and chemical properties of a
hazardous material can be found in: - ANSWER-Material Safety
Data Sheet
What is the function of the turbine auxiliary oil pump? - ANSWER-
Establish oil pressure during turbine start up
The rupture disc for a low pressure centrifugal refrigeration
machine is normally located on the: - ANSWER-Compressor
suction
What is the primary reason ribbed metal piping is used for
electrical wires connected to the refrigeration system shown
below? - ANSWER-It allows for flexibility and accounts for
vibrations
,2|Page
A multi cylinder reciprocating compressor uses cylinder unloaders
to regulate capacity, what would not occur if some of the
unloaders fail to operate when needed? - ANSWER-The chill
water temperature will increase
As shown in the picture below, the suction gauge of a condenser
water pump reads 55 PSI. The pipe supplying the pump is 75 feet
long and 12 inches in diameter. Approximately, how many gallons
of water do you expect to obtain if the pipe is drained completely?
- ANSWER-440
A water chiller system uses refrigerant R-123. A leak in the
evaporator shell may result in: - ANSWER-A higher than normal
high side pressure
Capacitors are used on refrigeration motors. Of the following, the
function of these devices is to: - ANSWER-Store electrical
chargers during starting and running the motor
Of the following, centrifugal refrigerant machine is best
characterized by: - ANSWER-A high volume, low pressure
machine
,3|Page
Which of the following ASHRAE refrigerant safety classifications
is the most flammable? - ANSWER-A3
Which of the following correctly describes the object in the picture
below? - ANSWER-Standpipe hose outlet, to put out fires in case
of emergency
Modern compressors usually seal the rotating shaft as it exits the
compressor housing a spring - ANSWER-Metal or carbon
The British Thermal Unit (BTU) is the measurement of heat of
energy. If 10 BTU's are transferred to 10 pounds of water, the
water temperature increase will be closest to: - ANSWER-1 deg F
A reciprocating compressor cylinder has a 10 inches bore and 14
inches stroke. The volume of the refrigerant , in cubic inches, will
be closer to: - ANSWER-1099
, 4|Page
An electrically operated control requires 24 volts to operate. To
change the available 110 volts to 24 volts - ANSWER-
Transformer
In an indirect refrigeration system, of the following, the one that
would not be used as a cooling medium for the building spaces
being cooled is: - ANSWER-R-22
On a steam turbine, what would cause the atmospheric valve to
open? - ANSWER-All answers (low vacuum in the surface
condenser, leaking tubes in the surface condenser, dirty tubes in
the surface condenser)
You are the engineer running a 2000-ton (steam driven turbine)
centrifugal rerigeration system, a refrigeration system supplies
chilled water to a college campus with multiple buildings. Making
your rounds, you notice that the condenser water pump #1 is
making a lot of noise, the discharger guage reading of the
condenser water pump is fluctuating drastically, and motor of the
condenser pump #1 is running very hot. Which of the following
would you take: - ANSWER-Turn on pump #2, shut off pump #1,
and troubleshoot pump #1
