RMO Review Exam UPDATED ACTUAL
QUESTIONS AND CORRECT 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: - CORRECT
ANSWER Lowering the condensing pressure
The heat removed from the refrigerant in a condenser is: - CORRECT
ANSWER Sensible and latent heat
Which of the following best describes how the cylinder unloader work? - CORRECT
ANSWER 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: - CORRECT ANSWER Difference between the high side and low side pressure
A superheated vapor is a: - CORRECT ANSWER 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: - CORRECT ANSWER A faulty cooling
tower water level controller
A centrifugal water pump is known as a lift pump when the: - CORRECT
ANSWER the water supply t o the pump suction inlet is below the pump level
A TXV is used to maintain constant: - CORRECT ANSWER 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? - CORRECT ANSWER Yes, this
temperature is too high for human comfort purpose
,The packing gland of a centrifugal pump serves to: - CORRECT ANSWER 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 -
CORRECT ANSWER Operation of the hot gas bypass valve
The most important reason to sub-cool the refrigerant in the condenser is to ensure that: -
CORRECT ANSWER A pure liquid refrigerant will enter the metering device
A low side float valve is used to maintain: - CORRECT ANSWER The level of
refrigerant ni the condenser
Regarding firesafety, which ASHRAE refrigerant safety classification indicates no
flammability and lowertoxicity? - CORRECT ANSWER A1
When an expansion valve is operating properly, at the end of the evaporator will contain: -
CORRECT ANSWER Only superheated vapor
In a steam turbine, what is the function of the Kingsbury thrust bearing - CORRECT
ANSWER 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
- CORRECT ANSWER 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 - CORRECT ANSWER 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: - CORRECT ANSWER Where no liquid refrigerant is present
, All liquid has been recovered from a system to be overhauled, the system - CORRECT
ANSWER 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? - CORRECT ANSWER Add additional make up water
to cooling tower
What device protects the steam turbine from excessive speed? - CORRECT
ANSWER 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 - CORRECT ANSWER Ammonia
On what characteristics is ASHRAE refrigerant safety group classification system: -
CORRECT ANSWER 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: - CORRECT
ANSWER Refrigerant recycling
Information about the physical and chemical properties of a hazardous material can be found
in: - CORRECT ANSWER 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? - CORRECT
ANSWER The discharge pressure wil increase
QUESTIONS AND CORRECT 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: - CORRECT
ANSWER Lowering the condensing pressure
The heat removed from the refrigerant in a condenser is: - CORRECT
ANSWER Sensible and latent heat
Which of the following best describes how the cylinder unloader work? - CORRECT
ANSWER 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: - CORRECT ANSWER Difference between the high side and low side pressure
A superheated vapor is a: - CORRECT ANSWER 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: - CORRECT ANSWER A faulty cooling
tower water level controller
A centrifugal water pump is known as a lift pump when the: - CORRECT
ANSWER the water supply t o the pump suction inlet is below the pump level
A TXV is used to maintain constant: - CORRECT ANSWER 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? - CORRECT ANSWER Yes, this
temperature is too high for human comfort purpose
,The packing gland of a centrifugal pump serves to: - CORRECT ANSWER 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 -
CORRECT ANSWER Operation of the hot gas bypass valve
The most important reason to sub-cool the refrigerant in the condenser is to ensure that: -
CORRECT ANSWER A pure liquid refrigerant will enter the metering device
A low side float valve is used to maintain: - CORRECT ANSWER The level of
refrigerant ni the condenser
Regarding firesafety, which ASHRAE refrigerant safety classification indicates no
flammability and lowertoxicity? - CORRECT ANSWER A1
When an expansion valve is operating properly, at the end of the evaporator will contain: -
CORRECT ANSWER Only superheated vapor
In a steam turbine, what is the function of the Kingsbury thrust bearing - CORRECT
ANSWER 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
- CORRECT ANSWER 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 - CORRECT ANSWER 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: - CORRECT ANSWER Where no liquid refrigerant is present
, All liquid has been recovered from a system to be overhauled, the system - CORRECT
ANSWER 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? - CORRECT ANSWER Add additional make up water
to cooling tower
What device protects the steam turbine from excessive speed? - CORRECT
ANSWER 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 - CORRECT ANSWER Ammonia
On what characteristics is ASHRAE refrigerant safety group classification system: -
CORRECT ANSWER 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: - CORRECT
ANSWER Refrigerant recycling
Information about the physical and chemical properties of a hazardous material can be found
in: - CORRECT ANSWER 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? - CORRECT
ANSWER The discharge pressure wil increase
