Refrigeration RT/RC Prep Quiz

Topics: All categories in the pool

Quiz Result Settings

1: Refrigeration devices shall be equipped with a ____ to protect against unexpected pressure due to a malfunction or fire?

  • Relief valve
  • T&P device
  • Temperature limiter device
  • Circuit Breaker

2: If the suction pressure is low and the evaporator temperature high, the cause will be a?

  • overcharged
  • compressor suction valve stuck open
  • too small evaporator
  • starved evaporator

3: The low pressure oil safety switch

  • never trips
  • must be reset manually
  • resets itself automatically
  • resets itself after the time delay has terminated

4: _____ alloys shall not be used in contact with an halogenated refrigerants.

  • Zinc
  • Nickel
  • Magnesium
  • Copper

5: An azeotropic refrigerant is

  • a mixture of two or more refrigerants that boil at about the same temperature minimizing temperature glide.
  • a mixture of two or more refrigerants that boil at much different temperatures causing temperature glide
  • a mixture of two or more refrigerants that boil at much different temperatures minimizing temperature glide
  • none of the above

6: Foaming of oil in a compressor is most likely to occur

  • when ambient temperature are low
  • at start-up
  • when there is insufficient air across the condenser(i.e., dirty coil)
  • when the evaporator temperatures are below 32F

7: Pressure limiting devices are not required for systems containing less then ________ refrigerants.

  • 22 lbs
  • 6.6 lbs
  • 13.9 lbs
  • 44 lbs

8: Sensible heat is the heat added to a substance to

  • change its state
  • cause evaporation
  • raise its temperature
  • freeze it

9: When an inspection is needed, how often must it be done?

  • every 18 months
  • annually
  • every 24 months
  • every 36 months

10: A chiller entering and leaving temperature difference is?

  • 5 degrees F
  • 20 degrees F
  • 10 degrees F
  • 50 degrees F

11: The Board of Boilers adopts by reference

  • MSCA Code
  • Montreal Protocol Safety Code
  • the MACS Pressure Vessel Code of Massachusetts
  • the 1997 ANSI/ASHRAE Safety Code

12: If the power element on an expansion valve should lose its charge, the valve would

  • Under feed
  • Over feed
  • Close
  • Stay open

13: The purpose of an accumulator is to

  • store excess refrigerant from the reciver
  • reduce friction loss to the flow of refrigerant
  • assure no liquid returns to the compressor
  • filter out impurities from the system

14: How many forces operate a thermostatic expansion valve?

  • 4
  • 1
  • 2
  • 3

15: Machinery rooms shall be vented to _____________ and utilizing mechanical ventilation.

  • the outdoors
  • Machinery rooms need not be vented
  • the return air ducted system
  • the mechanical room housing the refrigeration system

16: "P" represents ______ in the Watt's law formula

  • watts
  • amperage
  • reactance
  • voltage

17: How far from the ground does a relief valve need to be?

  • At least 25' above grade
  • At least 20' above grade
  • Not more than 3' above grade
  • At least 15' above grade

18: Which refrigerant is lighter than air?

  • R-717
  • R-11
  • R-123
  • R-134a

19: An evaporator coil located near heating coil shall have a pressure-relief device installed within ______ inches of the evaporator.

  • 48
  • 36
  • 18
  • 24

20: Group A3 refrigerants have a ______ flammability rating than Group B1 refrigerants

  • there is no Group B1 refrigerants
  • the same
  • higher
  • lower

21: Heat is a form of

  • energy
  • work
  • matter
  • power

22: High side floats are used on centrifugal chiller systems are are considered critically charged systems.

  • False
  • are obsolete.
  • True
  • depends on the type of refrigerant being used

23: What type of voltage cause a potential relay to open?

  • 24 volt supply from the thermostat
  • 120 volt line voltage
  • Pick-up voltage
  • none of the above

24: In a properly balanced system with valves open and properly adjusted, if the suction line is warm to the touch, its because of

  • moisture in the system
  • oil in evaporator
  • low head pressure
  • not enough oil in the system

25: A restaurant is classified as a

  • mixed occupancy
  • public assembly occupancy
  • large mercantile occupancy
  • commercial occupancy