Refrigeration RT/RC Prep Quiz

Topics: All categories in the pool

Quiz Result Settings

1: A mercury bulb controller is not recommended for

  • line or low voltage use
  • line voltage use
  • low voltage use
  • use where vibration is severe

2: A halide torch is most useful with a freon compression system

  • to sweat flanges on the refrigeration piping
  • to remove from from TXV's and evaporator coils
  • to release a sticking valve
  • to detect refrigeration leaks in piping joints

3: How are safety controls wired in a circuit?

  • Series
  • Parallel
  • Series/parallel
  • Either series or parallel

4: A rule of thumb in air conditioning is ____ CFM per ton?

  • 500
  • 100
  • 400
  • 600

5: What do you need to do when you install a new system?

  • Insulate the suction line before you take a superheat reading
  • Add refrigerant
  • Document the superheat and subcooling reading
  • Have it inspected

6: R-718 is rated unlimited for refrigeration quantity contained in a system. Why?

  • Because it's a non-flammable refrigerant
  • R-718 is not rated unlimited because it's a dangerous refrigerant
  • Because it's cheap
  • Because it's water

7: Three-phase motors have what type of windings?

  • three run windings
  • three run windings and 3 start windings
  • three start windings
  • one start winding and one run winding.

8: Low-side system leaks in a low-pressure chiller will often result in

  • air being pulled into the system
  • nitrogen leaking out of the system.
  • water being pulled into the system
  • system refrigerant leaking from the system

9: What device measures the specific gravity of a substance?

  • Hygrometer
  • Thermometer
  • Hydrometer
  • Manometer

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

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

11: What is the refrigerant dichlorodifluoromethane?

  • R-134A
  • R-22
  • R-123
  • R-12

12: What is used to check very low pressure?

  • Hydrometer
  • Hygrometer
  • Manometer
  • Velometer

13: The normal operating evaporator temperature of R-410A for air conditioning is typically

  • 32F
  • 158F
  • 155F
  • 45F

14: Fusible plugs shall not be used with pressure vessels of

  • 3 cubic feet or more
  • 3 cubic feet or less
  • 15 cubic feet or more
  • 15 square feet or less

15: Before you change the type of refrigerant in a refrigeration system, what three things must be done?

  • nothing must be done
  • place sign, check for leaks, insulate
  • make sure it's compatible, notify owner, notify A.H.J
  • you can't change refrigerants

16: A Lithium-bromide system is an absorption system that

  • uses ammonia as a refrigerant and lithium bromide as an absorbent
  • uses salts as an absorbent and lithium bromide as a refrigerant
  • uses water as a refrigerant and lithium bromide as an absorbent
  • uses water as a absorbent and lithium bromide as a refrigerant

17: In designing duct work, pressure and ______ need to be considered

  • length
  • CFM
  • duct sealant used
  • all of the above

18: On a single phase motor, when does the start winding cut out?

  • Start windings do no cut-out of the run cycle
  • At 75% of its full rated speed
  • At 25% of its full rated speed
  • At 50% of its full rated speed

19: How many gallons of water per pound of ammonia do you need?

  • 20
  • 1
  • 15
  • 5

20: Megaohm meters can detect a ground in the

  • up to 1,000 ohms
  • up to 1,000,000 ohms
  • 10,000,000 ohms or higher
  • up to 10,000 ohms

21: Megaohm meter's main function is

  • to detect weak motor winding insulation of a refrigeration or air conditioning compressor by creating high DC voltages to the compressor
  • to detect very high resistances to ground of refrigeration or air conditioning compressors
  • to test very high value capacitors for large 3-phase refrigeration compressors and blower motors.
  • Both a and b are correct

22: A R-22 system running with a condensing temperature of 110F and a 40F evaporator temperature will read pressures of ____ on the high side and ____ on the low side.

  • 226 psig, 68 psig
  • 350 psig, 120 psig
  • 257 psig, 77 psig
  • 455 psig, 185 psig

23: Increasing superheat will do what to your system?

  • Increase liquid flow
  • Nothing
  • Decrease liquid flow
  • Increase gas flow

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

  • Over feed
  • Under feed
  • Stay open
  • Close

25: An accumulator can be located between the

  • first stage and second stage compressors
  • condenser and evaporator
  • evaporator and compressor
  • compressor and condenser