Refrigeration RT/RC Prep Quiz

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Quiz Result Settings

1: The critical temperature of a refrigerant gas occurs when

  • the gas returns to a liquid
  • the gas is no longer saturated
  • any increase in pressure will not liquefy the gas
  • any decrease in pressure will cause condensation

2: Refrigerant is metered into the evaporator on a large centrifugal chiller thru the

  • low side of the system
  • high side float assembly
  • cap tube
  • none of the above

3: one BTU equals

  • 31.4 hp
  • 3.41 hp
  • Pi
  • 12,000 hp

4: It shall be the duty of the person in charge of the premises on which a refrigeration system containing more than ___ lbs of refrigerant is installed to provide a schematic drawing or panel giving directions for the operation of the system.

  • 50
  • 15
  • 55
  • 75

5: A crankcase heater has a supplied voltage of 100 volts and is drawing 1.4 amps. What is the resistance?

  • 80 ohms
  • 27 ohms
  • 104 ohms
  • 71 ohms

6: Halogenated refrigerants cannot be used with what material?

  • Stainless steel
  • Aluminum
  • Copper
  • Magnesium alloy

7: The reversing valve is commonly used

  • when the code requires a check valve
  • on multiple compressor systems
  • on all heat pumps
  • on commercial system that involve two different temperatures

8: On cooling towers, what causes the condenser water to drop

  • tower fans
  • ambient temperatures
  • sensible heat
  • evaporation of the water droplets

9: When using nitrogen for brazing, the pressure should be:

  • Very low
  • 50-100 psig
  • Slightly below atmospheric
  • 125 psig

10: What section governs pressure vessels?

  • OSHA
  • Section 8 ASHREA 15 ASME unfired
  • Section ASHREA 34
  • Section 1 ASHREA 15 ASME fired

11: Start to Run windings will have what resistance?

  • The most resistance value
  • All will be at equal values
  • Somewhere between the actual start winding and run winding resistance value
  • The least resistance value

12: Booster compressors connect to the ____ side of the compressor

  • oil side
  • vapor
  • liquid
  • low side

13: The Department that certifies the transportation of refrigerant is the

  • EPA
  • EPO
  • DOT
  • RSES

14: Which of the following controllers would you expect to be most sensitive to temperature changes?

  • low voltage t-stat
  • aquastat
  • line voltage t-stat
  • immersion controller

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

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

16: Electricity involves the movement of electrons in atoms

  • True
  • False

17: If the power element of an expansion valve should lose its charge the valve would

  • underfeed the evaporator
  • overfeed the evaporator
  • go closed
  • go open

18: What is an egress?

  • A valve put on the low side of the system to prevent frosting
  • An entrance or exit
  • An escape route
  • A code violation

19: When a pressure gauge is permanently installed on a system, it must be ___ times the design pressure of the system.

  • 2.2
  • 1
  • 1.5
  • 1.2

20: The level of voltage caused by back electromagnetic force that opens the contacts of a potential relay in order to take the start capacitor out of the circuit is

  • boost voltage
  • lift voltage
  • run voltage
  • pick up voltage

21: What kind of material can't be used on the outlet of a relief valve?

  • Copper
  • PVC
  • Aluminum
  • Stainless Steel

22: Refrigeration piping before being buried shall be

  • leak tested
  • encased in pipe duct
  • pressure tested
  • All of the above

23: What instrument is used to measure very high resistance?

  • meg ohmmeter
  • voltmeter
  • tape measure
  • ammeter

24: Liquid refrigerant R-22 enters an evaporator at 50.2 psig, 20F and leaves 37F, its pressure as it leaves will be

  • 50.2 psig
  • 66.1 psig
  • 43.3 psig
  • 70.8 psig

25: How many groups of refrigerants are there?

  • 7
  • 5
  • 3
  • 1