Refrigerant Machine Operator Test # 4

66 Questions | Total Attempts: 180

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Refrigerant Machine Operator Test # 4


Questions and Answers
  • 1. 
    What is the cooling medium of the cooling towers?
    • A. 

      Air

    • B. 

      Water

    • C. 

      Air and water 

    • D. 

      Fan 

  • 2. 
    If the temperature outside drops b 8 deg.C, what is the equivalent drop in def.F?
    • A. 

      4 deg.F

    • B. 

      40 deg.F

    • C. 

      14 deg.F

    • D. 

      8 deg.F

  • 3. 
    The primary function of the steam eductors on the surface condenser is to:
    • A. 

      Condense the steam

    • B. 

      Create a vacuum

    • C. 

      Separate the steam and air

    • D. 

      Safety device only

  • 4. 
    A valve that will not provide continuos flow of refrigerant through the circuit is the:
    • A. 

      Globe valve

    • B. 

      Service valve

    • C. 

      Solenoid valve

    • D. 

      TXV

  • 5. 
    When considering the rate of BTUs rejected by the condenser, an important point for the operator to remember is:
    • A. 

      Will increase if you oversize the tower 

    • B. 

      Will decrease as the water temperature goes down

    • C. 

      Will increase as the velocity goes up

    • D. 

      Will show no difference as long as the water temperature is the same

  • 6. 
    As the load on a reciprocating chiller decreases, the most correct sequence of operation is as follows 
    • A. 

      Compressor goes into hot gas by-pass, unloads and shuts off

    • B. 

      Compressor shuts off, unloads and then goes into hot gas by-pass

    • C. 

      Compressor unloads, then hot gas by-passes and shuts down

    • D. 

      None of the above 

  • 7. 
    An RMO notices that the diameter of the suction line is 36" and the diameter of the discharge line is 18".  What can we determine from this statement?
    • A. 

      The unit is piped wrong because the diameters should be opposite

    • B. 

      The cold refrigerant vapor needs less space than a hot vapor 

    • C. 

      The high pressure line needs more diameter to handle the pressure

    • D. 

      The higher the vapor pressure is, the less volume is needed

  • 8. 
    As an RMO, you are responsible for two air cooled split systems handling computer rooms and are required to run all year round.  These units are most likely equipped with:
    • A. 

      Crankcase heaters and condenser damper

    • B. 

      Crankcase heater and hot gas by-pass

    • C. 

      Condenser damper and VFD

    • D. 

      Condenser damper and hot gas by-pass

  • 9. 
    You notice that the second stage compressor on your reciprocating chiller has foaming in the oil sight glass.  As an operator you should check for:
    • A. 

      Excessive charge 

    • B. 

      Burnt out crankcase heater

    • C. 

      Moisture in the system 

    • D. 

      Too much oil 

  • 10. 
    On a water cooled chiller, the heat that is absorbed by the chilled water is:
    • A. 

      Rejected to the ambient air as sensible heat 

    • B. 

      Rejected as latent and sensible heat heat to the ambient air

    • C. 

      Minimal in comparison to the volume of water 

    • D. 

      Rejected by the compressor

  • 11. 
    Types of steam turbines include all of the following except:
    • A. 

      Impulse steam turbines

    • B. 

      Reaction steam turbines

    • C. 

      Impulse reaction steam turbine

    • D. 

      None of the above

  • 12. 
    As an RMO inspecting the discharge line of a reciprocating compressor you notice a device at the furthest point away from the compressor.  This device is most likely there to:
    • A. 

      Clean the refrigerant

    • B. 

      Separate the moisture from the refrigerant 

    • C. 

      Return oil to the compressor

    • D. 

      Muffle the noise from the compressor

  • 13. 
    Oil that has been separated from the refrigerant is returned to the compressor and tied into the  
    • A. 

      Oil charging valve 

    • B. 

      Discharge service valve 

    • C. 

      Oil pump suction 

    • D. 

      Compressor crankcase

  • 14. 
    What is the state of the refrigerant as it enters and exits the compressor?
    • A. 

      Low temperature liquid in and high temperature liquid out 

    • B. 

      Low temperature vapor in and high temperature vapor out 

    • C. 

      Low temperature in and high temperature out 

    • D. 

      Low pressure in and high pressure out 

  • 15. 
    When looking at a wiring diagram for a 20 ton split system, you would expect to find the following information.
    • A. 

      The path that current takes through the system 

    • B. 

      A point to point detail of how the wires are run 

    • C. 

      A pictorial of component position 

    • D. 

      Amp ratings for all loads 

  • 16. 
    The design and sequence of operations of an automatic expansion valve causes it to: 
    • A. 

      Decrease superheat on an increase in load 

    • B. 

      Increase superheat on a decrease of load 

    • C. 

      Close on decrease in pressure 

    • D. 

      Close on an increase in pressure 

  • 17. 
    When looking at a large semi-hermetic reciprocating compressor,  you would expect to find:
    • A. 

      Suction and discharge lines parallel to each other

    • B. 

      Suction and discharge lines perpendicular to each other 

    • C. 

      Depends on the amount of cylinders

    • D. 

      Suction on top and discharge off the bottom 

  • 18. 
    The sole refrigeration engineer on duty in a building is permitted to leave the building refrigeration system is in operation only when
    • A. 

      Lunch or dinner occur

    • B. 

      System is in automatic operation 

    • C. 

      Relieved by another licensed refrigeration engineer 

    • D. 

      The assistant provides coverage or supervision

  • 19. 
    When conducting a routine tour of the plant, an RMO notices a significant increase in superheat for a reciprocating compressor. Of the following, the most likely cause of this would be?
    • A. 

      Scale particles lodged in the TEV

    • B. 

      Unraveling of the insulation covering the thermal bulb of the TEV

    • C. 

      Overcharge of refrigerant 

    • D. 

      Noncondensables in the system 

  • 20. 
    An automatic purge unit is required on units:
    • A. 

      With centrifugal compressors

    • B. 

      Containing low pressure refrigerants

    • C. 

      Absorption systems 

    • D. 

      Double indirect open spray systems 

  • 21. 
    Efficiency of the refrigeration cycle is affected by the operation of the condenser. Of the following, a more efficient condenser on a centrifugal compressor results from 
    • A. 

      Raising the condenser liquid level to maximum 

    • B. 

      Produce large amounts of subcooling 

    • C. 

      Raising the condenser head pressure 

    • D. 

      Lowering the condenser pressure 

  • 22. 
    Shaft glands on a steam turbine are located:
    • A. 

      Front and rear of turbine 

    • B. 

      Wherever the shaft emerges from the casing or steam could leak 

    • C. 

      Wherever air could leak out of the turbine 

    • D. 

      Wherever oil can leak from the lubrication system 

  • 23. 
    You are the RMO of a facility which contains a 750 ton centrifugal Trane chiller.  The chief ask you to order extra refrigerant for the upcoming season.  If the machine charge is determined to be 1500lbs, how much refrigerant can you store without being in violation of the code?
    • A. 

      Whatever the chief engineer deems safe 

    • B. 

      Whatever can be tied down and stored safely 

    • C. 

      200lbs of refrigerant 

    • D. 

      330 lbs of refrigerant 

  • 24. 
    When changing water to ice, what must be removed?
    • A. 

      Specific heat 

    • B. 

      Latent heat 

    • C. 

      Sensible heat 

    • D. 

      N/A

  • 25. 
    A truck with 5 tons of ice stuck on the side of the road with no refrigeration.  How many BTUs is required to melt 5 tons of ice at 32 deg F to 5 tons of water at 32 deg F in 1 
    • A. 

      60,000 BTUs

    • B. 

      1,400,000 BTUs

    • C. 

      288,000 BTUs

    • D. 

      Cannot be done in 1 hr.

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