RMO REVIEW EXAM QUESTIONS & ANSWERS
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: - Answers
:Lowering the condensing pressure
The heat removed from the refrigerant in a condenser is: - Answers :Sensible and latent
heat
Which of the following best describes how the cylinder unloader work? - Answers :Keep
in the suction valve opened while the compressor is in the return stroke
The amount of refrigerant that flows through the orifices of a economizar is determined
by the: - Answers :Difference between the high side and low side pressure
A superheated vapor is a: - Answers :Dry vapor above the saturation temperature
A refrigeration engineer verifies thats a condenser water pump is cavitating. Of the
following the most likely causef o r this condition is: - Answers :A faulty cooling tower
water level controller
A centrifugal water pump is known as a lift pump when the: - Answers :the water supply
t o the pump suction inlet is below the pump level
A TXV is used to maintain constant: - Answers :Evaporator superheat
The chilled water supply to the building is 55F. If the chiller is being used for human
comfort, should you be concerned about this, and why? - Answers :Yes, this
temperature is too high for human comfort purpose
The packing gland of a centrifugal pump serves to: - Answers :The drip part of the
packing gland gives evidencethat there is water in the pump
Capacity control of a reciprocating hermetic compressor is typically achieved through -
Answers :Operation of the hot gas bypass valve
The most important reason to sub-cool the refrigerant in the condenser is to ensure that:
- Answers :A pure liquid refrigerant will enter the metering device
A low side float valve is used to maintain: - Answers :The level of refrigerant ni the
condenser
Regarding firesafety, which ASHRAE refrigerant safety classification indicates no
flammability and lowertoxicity? - Answers :A1
,When an expansion valve is operating properly, at the end of the evaporator will
contain: - Answers :Only superheated vapor
In a steam turbine, what is the function of the Kingsbury thrust bearing - Answers
:Maintain axial positioning of the rotor shaft
Copper tubing refrigerant lines must be installed for a new system. it is a well known
service practice that tubing collapses at bends that must be made, the refrigerant
engineer should use - Answers :Lever type tubing bender
A reciprocating compressor is making a knocking sound during operation. parts are not
causing the knocking, what is probably the cause - Answers :The slugging of the liquid
refrigerant
In order for a refrigerant to become superheated it must be heated in a section of the
low side refrigerant line: - Answers :Where no liquid refrigerant is present
All liquid has been recovered from a system to be overhauled, the system - Answers
:Should not be opened until all vapor has been recovered
You are the engineer running a 2000-ton (steam-driven turbine) centrifugal refrigeration
system, a refrigeration system supplies chilled water to a college campus with multiple
buildings.
During the course of making your rounds,you check the 9 cell cooling tower on the roof.
You note the water level in all of the cooling tower cells is very low. Which one of the
following immediate action would take? - Answers :Add additional make up water to
cooling tower
What device protects the steam turbine from excessive speed? - Answers :Governor
assembly
Refrigerants are characterized by their physical properties included flashpoint,
refrigeration effect, and others. Of the refrigerants in commercial and industrial the
highest latent heat and refrigerant - Answers :Ammonia
On what characteristics is ASHRAE refrigerant safety group classification system: -
Answers :flammability and toxicity
Of the following, an example of an in-line refrigerant cleaning system that may be used
with a centrifugal compressor containing R123 refrigerant is: - Answers :Refrigerant
recycling
Information about the physical and chemical properties of a hazardous material can be
found in: - Answers :Material Safety Data Sheet
, 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? - Answers
:The discharge pressure wil increase
A water chiller system uses refrigerant R123. Aleak in the evaporator shell mat result in
- Answers :Setting of the refrigerant monitor alarm
Capacitors are used on refrigeration motors. Of the following, the function of these
devices is to? - Answers :Store electrical charges during starting and running the motor
Of the following, centrifugal refrigerant machine is best characterized by: - Answers
:High volume low pressure machine
Which of the following ASHRAE refrigerant safety classification is the most flammable?
- Answers :A3
Which of the following correctly describes theobject in the picture below? - Answers
:Standpipe hose outlet, to put out fires in case of emergency
Modern compressors usually seal the rotating shaft as it exits the loaded seal made of -
Answers :Metal or carbon
The British Thermal Unit (BTU) is the measurement of heat ofenergy.
10 pounds of water, If 10 BTU are transferred to the water temperature increase will be
closest to: - Answers :1F
A reciprocating compressor cylinder has a 10inches bore and 14 inches stroke.the
volume of refrigerant,in cubic inches, will be closer to
V=3.14xrxrxL
V=3.14x5(5)x14
V=1099.3 in3 - Answers :1099
An electrically operated control requires 24 volts to operate. to change the available 110
volts to 24volts - Answers :Transformer
In a n indirect refrigeration system, oft h e following, the one thatwould not be used
medium fort h e building spaces being cooled is: - Answers :R22 refrigerant
On a steam turbine, what would cause the atmospheric valve to open?
A. Low vacuum int h e surface condenser
B. Leaking tubes in the surface condenser
C. All answer are correct
D. Dirty tubes in the surface condenser - Answers :All answers are correct
Electric devices may be used to provide built in defrosting of refrigeration machine
evaporator units. These devices are classified as - Answers :Resistors
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: - Answers
:Lowering the condensing pressure
The heat removed from the refrigerant in a condenser is: - Answers :Sensible and latent
heat
Which of the following best describes how the cylinder unloader work? - Answers :Keep
in the suction valve opened while the compressor is in the return stroke
The amount of refrigerant that flows through the orifices of a economizar is determined
by the: - Answers :Difference between the high side and low side pressure
A superheated vapor is a: - Answers :Dry vapor above the saturation temperature
A refrigeration engineer verifies thats a condenser water pump is cavitating. Of the
following the most likely causef o r this condition is: - Answers :A faulty cooling tower
water level controller
A centrifugal water pump is known as a lift pump when the: - Answers :the water supply
t o the pump suction inlet is below the pump level
A TXV is used to maintain constant: - Answers :Evaporator superheat
The chilled water supply to the building is 55F. If the chiller is being used for human
comfort, should you be concerned about this, and why? - Answers :Yes, this
temperature is too high for human comfort purpose
The packing gland of a centrifugal pump serves to: - Answers :The drip part of the
packing gland gives evidencethat there is water in the pump
Capacity control of a reciprocating hermetic compressor is typically achieved through -
Answers :Operation of the hot gas bypass valve
The most important reason to sub-cool the refrigerant in the condenser is to ensure that:
- Answers :A pure liquid refrigerant will enter the metering device
A low side float valve is used to maintain: - Answers :The level of refrigerant ni the
condenser
Regarding firesafety, which ASHRAE refrigerant safety classification indicates no
flammability and lowertoxicity? - Answers :A1
,When an expansion valve is operating properly, at the end of the evaporator will
contain: - Answers :Only superheated vapor
In a steam turbine, what is the function of the Kingsbury thrust bearing - Answers
:Maintain axial positioning of the rotor shaft
Copper tubing refrigerant lines must be installed for a new system. it is a well known
service practice that tubing collapses at bends that must be made, the refrigerant
engineer should use - Answers :Lever type tubing bender
A reciprocating compressor is making a knocking sound during operation. parts are not
causing the knocking, what is probably the cause - Answers :The slugging of the liquid
refrigerant
In order for a refrigerant to become superheated it must be heated in a section of the
low side refrigerant line: - Answers :Where no liquid refrigerant is present
All liquid has been recovered from a system to be overhauled, the system - Answers
:Should not be opened until all vapor has been recovered
You are the engineer running a 2000-ton (steam-driven turbine) centrifugal refrigeration
system, a refrigeration system supplies chilled water to a college campus with multiple
buildings.
During the course of making your rounds,you check the 9 cell cooling tower on the roof.
You note the water level in all of the cooling tower cells is very low. Which one of the
following immediate action would take? - Answers :Add additional make up water to
cooling tower
What device protects the steam turbine from excessive speed? - Answers :Governor
assembly
Refrigerants are characterized by their physical properties included flashpoint,
refrigeration effect, and others. Of the refrigerants in commercial and industrial the
highest latent heat and refrigerant - Answers :Ammonia
On what characteristics is ASHRAE refrigerant safety group classification system: -
Answers :flammability and toxicity
Of the following, an example of an in-line refrigerant cleaning system that may be used
with a centrifugal compressor containing R123 refrigerant is: - Answers :Refrigerant
recycling
Information about the physical and chemical properties of a hazardous material can be
found in: - Answers :Material Safety Data Sheet
, 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? - Answers
:The discharge pressure wil increase
A water chiller system uses refrigerant R123. Aleak in the evaporator shell mat result in
- Answers :Setting of the refrigerant monitor alarm
Capacitors are used on refrigeration motors. Of the following, the function of these
devices is to? - Answers :Store electrical charges during starting and running the motor
Of the following, centrifugal refrigerant machine is best characterized by: - Answers
:High volume low pressure machine
Which of the following ASHRAE refrigerant safety classification is the most flammable?
- Answers :A3
Which of the following correctly describes theobject in the picture below? - Answers
:Standpipe hose outlet, to put out fires in case of emergency
Modern compressors usually seal the rotating shaft as it exits the loaded seal made of -
Answers :Metal or carbon
The British Thermal Unit (BTU) is the measurement of heat ofenergy.
10 pounds of water, If 10 BTU are transferred to the water temperature increase will be
closest to: - Answers :1F
A reciprocating compressor cylinder has a 10inches bore and 14 inches stroke.the
volume of refrigerant,in cubic inches, will be closer to
V=3.14xrxrxL
V=3.14x5(5)x14
V=1099.3 in3 - Answers :1099
An electrically operated control requires 24 volts to operate. to change the available 110
volts to 24volts - Answers :Transformer
In a n indirect refrigeration system, oft h e following, the one thatwould not be used
medium fort h e building spaces being cooled is: - Answers :R22 refrigerant
On a steam turbine, what would cause the atmospheric valve to open?
A. Low vacuum int h e surface condenser
B. Leaking tubes in the surface condenser
C. All answer are correct
D. Dirty tubes in the surface condenser - Answers :All answers are correct
Electric devices may be used to provide built in defrosting of refrigeration machine
evaporator units. These devices are classified as - Answers :Resistors
