FDNY Z51 RMO REVIEW UPDATED SET QUESTIONS
AND ANSWERS RATED A+
✔✔Electric devices may be used to provide built in defrosting of refrigeration machine
evaporator units. these devices are classified as - ✔✔Resistors
✔✔The flash point of compressor lubricating oil: - ✔✔Should be higher than the
compression temperature
✔✔The primary way of achieving capacity control of a centrifugal compressor is by; -
✔✔Adjustment of the impeller inlet pre-rotation vanes
✔✔Cooling tower water requires the addition of chemical additives in order to: -
✔✔Reduce the formation of scale and algae
✔✔In the picture below describe the equipment's function? - ✔✔Remove non
condensable from the condenser
✔✔the viscosity of lubrication oil is described by a number. a low viscosity number
describes oil that: - ✔✔Flows easily
✔✔The most likely reason for a refrigeration engineer to use a psychrometer is to
measure - ✔✔Relative humidity level of the atmosphere
✔✔The most important reason to use at least two compressors in a cascade system is
to: - ✔✔Avoid very high compression ratio for each compressor
✔✔The suction service valve of a reciprocating compressor is front seated and the
compressor runs until the low pressure cut-out shut the compressor off. when the
machine is stopped, the refrigeration engineer notices that the suction pressure
, increase rapidly. the most probable cause of this pressure rise: - ✔✔Malfunction of a
compressor valve
✔✔Regarding the functioning of a steam turbine, why is it advisable to keep moisture in
the inlet low as possible? - ✔✔Keeps turbine blades wear to minimum
✔✔According to the attached Material Safety Data Sheet (MSDS) R134 is a - ✔✔Clear,
odorless liquid and vapor
✔✔Under normal condition, the refrigerant enters the compressor as a: - ✔✔Low
pressure superheated vapor and leaves as a high pressure vapor
✔✔While operating an R-22 single acting compressor system, the refrigeration engineer
noticed oil foaming in the crankcase. this condition most likely, would have been caused
by a : - ✔✔Sudden drop in the crankcase pressure
✔✔Assume that an engineer is able to observe refrigerant water and oil together. the
fluids would settle in the container from top to bottom: - ✔✔Oil, water, refrigerant
✔✔What is the function of the vacuum breaker in a steam turbine. - ✔✔To achieve a
faster coast down cycle
✔✔An equalizer line on a TXV is used to: - ✔✔Compensate for the pressure drop
across the evaporator coil
✔✔If R134 accidentally touches a refrigerant engineer's skin, what first aid should be
applied from the MSDS? - ✔✔Promptly flush skin with water until all chemical is
removed
✔✔In a multi stage centrifugal compressor, each stage: - ✔✔Is identical in volume to
the other stages
✔✔A refrigeration engineer notices excessive cycling of the temperature control for a
reciprocating compressor refrigeration unit. the crankcase temperature is high, the
compressor discharge temperature low, the suction line temperature high. of the
following the one that may causing this set condition. - ✔✔Faulty compressor valves
✔✔On an operating centrifugal compressor refrigerant unit, the refrigeration engineer
notices that the compressor is short cycling. the unit is using low side float valve as a
metering device. of the following requirements this would indicate that: - ✔✔The system
is undercharged with refrigerant
✔✔The vessel depicted below may used in connection with - ✔✔Refrigerant recovery
AND ANSWERS RATED A+
✔✔Electric devices may be used to provide built in defrosting of refrigeration machine
evaporator units. these devices are classified as - ✔✔Resistors
✔✔The flash point of compressor lubricating oil: - ✔✔Should be higher than the
compression temperature
✔✔The primary way of achieving capacity control of a centrifugal compressor is by; -
✔✔Adjustment of the impeller inlet pre-rotation vanes
✔✔Cooling tower water requires the addition of chemical additives in order to: -
✔✔Reduce the formation of scale and algae
✔✔In the picture below describe the equipment's function? - ✔✔Remove non
condensable from the condenser
✔✔the viscosity of lubrication oil is described by a number. a low viscosity number
describes oil that: - ✔✔Flows easily
✔✔The most likely reason for a refrigeration engineer to use a psychrometer is to
measure - ✔✔Relative humidity level of the atmosphere
✔✔The most important reason to use at least two compressors in a cascade system is
to: - ✔✔Avoid very high compression ratio for each compressor
✔✔The suction service valve of a reciprocating compressor is front seated and the
compressor runs until the low pressure cut-out shut the compressor off. when the
machine is stopped, the refrigeration engineer notices that the suction pressure
, increase rapidly. the most probable cause of this pressure rise: - ✔✔Malfunction of a
compressor valve
✔✔Regarding the functioning of a steam turbine, why is it advisable to keep moisture in
the inlet low as possible? - ✔✔Keeps turbine blades wear to minimum
✔✔According to the attached Material Safety Data Sheet (MSDS) R134 is a - ✔✔Clear,
odorless liquid and vapor
✔✔Under normal condition, the refrigerant enters the compressor as a: - ✔✔Low
pressure superheated vapor and leaves as a high pressure vapor
✔✔While operating an R-22 single acting compressor system, the refrigeration engineer
noticed oil foaming in the crankcase. this condition most likely, would have been caused
by a : - ✔✔Sudden drop in the crankcase pressure
✔✔Assume that an engineer is able to observe refrigerant water and oil together. the
fluids would settle in the container from top to bottom: - ✔✔Oil, water, refrigerant
✔✔What is the function of the vacuum breaker in a steam turbine. - ✔✔To achieve a
faster coast down cycle
✔✔An equalizer line on a TXV is used to: - ✔✔Compensate for the pressure drop
across the evaporator coil
✔✔If R134 accidentally touches a refrigerant engineer's skin, what first aid should be
applied from the MSDS? - ✔✔Promptly flush skin with water until all chemical is
removed
✔✔In a multi stage centrifugal compressor, each stage: - ✔✔Is identical in volume to
the other stages
✔✔A refrigeration engineer notices excessive cycling of the temperature control for a
reciprocating compressor refrigeration unit. the crankcase temperature is high, the
compressor discharge temperature low, the suction line temperature high. of the
following the one that may causing this set condition. - ✔✔Faulty compressor valves
✔✔On an operating centrifugal compressor refrigerant unit, the refrigeration engineer
notices that the compressor is short cycling. the unit is using low side float valve as a
metering device. of the following requirements this would indicate that: - ✔✔The system
is undercharged with refrigerant
✔✔The vessel depicted below may used in connection with - ✔✔Refrigerant recovery
