AC 432 Refrigeration Systems

68 Questions | Total Attempts: 579

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Refrigeration System Quizzes & Trivia

Refrigeration is used in different appliances around us, most commonly in refrigerators in our houses and places of work. How conversant are you with the refrigeration system, functionality and how to repair broken parts? Give this test on the system a try and polish up what you have forgotten before the finals.


Questions and Answers
  • 1. 
    The capacity of an evaporator is affected by ____.
    • A. 

      The saturation pressure of the low side of the system

    • B. 

      The saturation pressure of the high side of the system

    • C. 

      The amount of evaporator superheat

    • D. 

      All of the above

  • 2. 
    A forced draft medium temperature evaporator would ____.
    • A. 

      Be defrosted by off-cycle defrost

    • B. 

      Not need to be defrosted

    • C. 

      Need electric defrost

    • D. 

      Need a hot gas defrost

  • 3. 
    A forced draft high temperature evaporator would ____.
    • A. 

      Have its fins very close together

    • B. 

      Not need to be defrosted

    • C. 

      Need a hot gas defrost

    • D. 

      Both a and b

  • 4. 
    During the defrost cycle of a forced draft low temperature evaporator, the evaporator fan would ____.
    • A. 

      Remain on to speed up the defrost

    • B. 

      Turn off

    • C. 

      Cycle with the condenser

    • D. 

      Cycle with the compressor

  • 5. 
    If an evaporator has a pressure drop of 10 psig and the low side pressure is 15 psig, what is the pressure at the inlet of the evaporator?
    • A. 

      10 psig

    • B. 

      25 psig

    • C. 

      15 psig

    • D. 

      5 psig

  • 6. 
    Excess evaporator superheat ____.
    • A. 

      Is desired to prevent liquid from entering the compressor

    • B. 

      Will reduce the cooling capacity of the system

    • C. 

      Can be removed by removing refrigerant from the system

    • D. 

      Will cause the system to go into defrost

  • 7. 
    If a low temperature evaporator is forming excess ice, which of the following could be a possible problem?
    • A. 

      The evaporator fan motor is defective.

    • B. 

      The unit is not staying in defrost long enough.

    • C. 

      The defrost heater is defective.

    • D. 

      All of the above are correct.

  • 8. 
    If a high temperature evaporator is forming ice, which of the following is a possible problem?
    • A. 

      Evaporator fan not running

    • B. 

      Compressor not running

    • C. 

      Condenser fan not running

    • D. 

      No problem, ice formation normal

  • 9. 
    If a low temperature evaporator is forming ice, which of the following is a possible problem?
    • A. 

      Evaporator fan not running

    • B. 

      Compressor not running

    • C. 

      Condenser fan not running

    • D. 

      No problem, ice formation normal

  • 10. 
    If an R-12 refrigeration system is operating with a 25.4 psig suction pressure, what is the evaporator superheat if the evaporator outlet temperature is 34°F?
    • A. 

      9°F

    • B. 

      59°F

    • C. 

      34°F

    • D. 

      25°F

  • 11. 
    A typical evaporator operating temperature in an air-conditioning system is ____.
    • A. 

      40°F

    • B. 

      55°F

    • C. 

      75°F

    • D. 

      200°F

  • 12. 
    A large capacity evaporator would probably have ____.
    • A. 

      Stainless steel tubing

    • B. 

      An excess of liquid refrigerant

    • C. 

      An excess of vapor refrigerant

    • D. 

      Multiple refrigerant circuits

  • 13. 
    If the application requires a coil design to operate below 32°F, there must be provision for ____.
    • A. 

      Flooding the evaporator

    • B. 

      Adding the evaporator

    • C. 

      Defrost

    • D. 

      Suction pressure control

  • 14. 
    The heat required for off-cycle defrost is obtained from ____.
    • A. 

      Supplemental electric heat when the system is shut down

    • B. 

      Hot gas when the system is operating

    • C. 

      The space temperature when the compressor is off

    • D. 

      The space temperature when the compressor is off

  • 15. 
    A direct expansion-type evaporator is also called a ____.
    • A. 

      Flooded evaporator

    • B. 

      Dry-type evaporator

    • C. 

      Multi-circuit evaporator

    • D. 

      Stamped evaporator

  • 16. 
    A refrigeration system designed for the storage of flowers or candy is considered a ____ type.
    • A. 

      High temperature

    • B. 

      Medium temperature

    • C. 

      Low temperature

    • D. 

      Sharp freezing

  • 17. 
    A typical superheat for an evaporator operating under normal conditions would be ____.
    • A. 

      14 to 16°F

    • B. 

      4 to 6°F

    • C. 

      8 to 12°F

    • D. 

      6 to 8°F

  • 18. 
    When a system with a water-cooled condenser cycles off, the water regulating valve should ____.
    • A. 

      Remain open during the off cycle

    • B. 

      Close, since the head pressure is lower

    • C. 

      Open all the way to remove any residual heat

    • D. 

      Re-calibrate itself to maintain the new lower head pressure

  • 19. 
    A normally operating water-cooled condenser is operating with a 10° differential between water in and water out. If the amount of 85°F water going through the condenser is reduced, which of the following is a possible temperature of the water leaving the condenser?
    • A. 

      75°F

    • B. 

      0°F

    • C. 

      95°F

    • D. 

      105°F

  • 20. 
    A normally operating water-cooled condenser is operating with a 10° differential between water in and water out. If scale forms on the water tubes and the entering water is 85°F, which of the following is possible?
    • A. 

      The outlet water will be 88°F.

    • B. 

      The system head pressure will rise

    • C. 

      The water regulating valve will close.

    • D. 

      Both a and b are correct.

  • 21. 
    Which of the following would allow a system to operate more efficiently?
    • A. 

      Condenser that had refrigerant leaving with 10°F of superheat

    • B. 

      Condenser that had refrigerant leaving with 15° of subcooling

    • C. 

      Condenser that had refrigerant leaving as 100% vapor

    • D. 

      Condenser that had refrigerant leaving with 10° of subcooling

  • 22. 
    If an R-12 refrigeration system has its air-cooled condensing unit on a 100°F roof and the condenser outlet temperature (refrigerant) is 115°F, with how much subcooling is the condenser operating?
    • A. 

      30°F

    • B. 

      15°F

    • C. 

      100°F

    • D. 

      130°F

  • 23. 
    Which of the following condensers is the most efficient?
    • A. 

      Forced draft air-cooled

    • B. 

      Induced draft air-cooled

    • C. 

      Water-cooled parallel flow

    • D. 

      Water-cooled counter flow

  • 24. 
    An air-cooled condenser that is operating in a climate that has four distinct seasons must ____.
    • A. 

      Have some type of head pressure control

    • B. 

      Use a water regulating valve

    • C. 

      Have a multi-circuit evaporator

    • D. 

      Operate with zero degrees of subcooling

  • 25. 
    What can be used to maintain the head pressure of a system with a water-cooled condenser?
    • A. 

      Fan cycling

    • B. 

      Dampers or louvers

    • C. 

      Water regulating valve

    • D. 

      All of the above

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