Refrigeration RT/RC Prep Quiz

Topics: All categories in the pool

Quiz Result Settings

1: On a ammonia compressor, the pressure of a forced fed oil pump is changed by varying the

  • cooling temperature set-point
  • adjustment of the spring tension of the TXV
  • opening at the pump inlet
  • opening at the pump outlet

2: The color code of a tank of ammonia is

  • light green
  • white
  • silver
  • lavender

3: Which refrigerant(s) is an HFC?

  • R-22
  • R-410A
  • R-502
  • All of the above

4: A chiller entering and leaving temperature difference is?

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

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

  • Hydrometer
  • Manometer
  • Hygrometer
  • Thermometer

6: What refrigerant is an inorganic compound?

  • R-410A
  • R-132A
  • R-22
  • Ammonia

7: Ashrae states that the equipment on a building needs to conform to adjacent buildings classifications when within ____ feet from opening and intakes.

  • 50
  • 15
  • 20
  • 75

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

  • oil side
  • vapor
  • liquid
  • low side

9: In a refrigeration system, you open a valve from the condenser and collect some material on a clean white sheet of bond paper, which of the following would you most likely be testing for?

  • checking the level of refrigerant in the system
  • testing for oil in the system
  • testing for moisture in the system
  • none of the above

10: The principle used in continuous type absorption systems is

  • Charles's Law
  • Ohm's Law
  • Boyle's Law
  • Dalton's Law

11: An oil pressure safety switch should be set at

  • 5 to 10 psi below low side pressure
  • 5 to 10 psi above low side pressure
  • 10 to 15 psi below low side pressure
  • 10-15 psi above low side pressure

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

  • 600
  • 100
  • 400
  • 500

13: Ammonia is under what safety classification?

  • A3
  • B2
  • B3
  • B1

14: 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
  • pick-up voltage
  • lift voltage
  • run voltage

15: Systems containing more than 110 pounds must have stop valves located at the

  • compressor suction inlet
  • compressor discharge outlet
  • receiver inlet and outlet
  • All of the above

16: 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
  • 455 psig, 185 psig
  • 257 psig, 77 psig
  • 350 psig, 120 psig

17: If a liquid receiver is designed to receive the refrigerant charge during a pumpdown procedure, it shall have the capacity to

  • release the charge when the pressure exceeds 310 psig or higher
  • receive the pumpdown charge
  • hold up to 110% of the pumpdown charge
  • Pumpdown procedures are not allowed with systems containing liquid recievers

18: Class T machine room

  • shall have refrigerant leak detecting systems installed inside and outside the room
  • shall have remote controls to stop the action of the refrigerant compressor
  • shall include closets used for setting equipment
  • has no flame producing apparatus permanently installed

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

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

20: Pressure vessels having an inside diameter of 6” or less shall be protected by

  • Pressure vessels having an inside diameter of 6” or less need no such protection unless otherwise specified
  • a pressure relief device
  • either a fusible plug or a pressure relief device
  • a fusible plug

21: R-123 belongs to Group

  • B-1
  • B-2
  • A-3
  • B-3

22: Emergency shutdown procedures, including precautions to be observed in case of a breakdown or leak over 55 lbs of refrigerant charge, shall be displayed on a conspicuous card located as near as possible to the

  • boiler
  • outside the machinery room
  • compressor
  • evaporator

23: Which is considered the more efficient condenser?

  • water cooled
  • fan cooled
  • spray cooled
  • air cooled

24: The heat picked up in the evaporator must equal to

  • the heat giving by the condenser
  • the heat lost by the medium being cooled
  • the heat gained by the condenser
  • the heat of compression

25: What effect does the temperature of air have on humidity?

  • warmer air holds more moisture then cooler air
  • cooler air holds more moisture then warmer air
  • air has no effect of humidity
  • none of the above