Refrigeration RT/RC Prep Quiz

Topics: All categories in the pool

Quiz Result Settings

1: What is used to check very low pressure?

  • Hygrometer
  • Manometer
  • Velometer
  • Hydrometer

2: What is a high-side float?

  • Located in the liquid line entering the evaporator, so when the refrigerant level is higher in the liquid line than the evaporator, the float rises to allow more refrigerant flow into the evaporator
  • Located in the liquid line entering the evaporator, is a float-type metering device that rises to reduce refrigerant flow when the liquid refrigerant level rises in the high side of the chiller
  • An electronic-type metering device that contains a float assembly within the device which can accurately meter refrigerant into the evaporator as the load varies
  • Located in the evaporator, is a float-type metering device that rises to reduce refrigerant flow when the liquid refrigerant level rises in the low side of the chiller

3: RPM's of a centrifugal compressor are at approximately?

  • 10,000
  • 30,000
  • 500
  • 15,000

4: A tachometer is an instrument used to measure

  • RPM
  • air velocity
  • static pressure
  • speed

5: Field Inspections of refrigeration and A/C systems in Massachusetts shall be made by

  • District Engineering Inspectors
  • Commissioned Inspectors
  • Master licensed Technician
  • both a or b

6: Liquid line filter-driers on a 410A system must be rated for no less than

  • 1000 psig
  • 200 psig
  • 400 psig
  • 600 psig

7: What is the minimum size wire you can use on a 30 amp circuit?

  • 16 AWG
  • 10 AWG
  • 12 AWG
  • 14 AWG

8: Copper and its alloys shall not be used with ammonia

  • True
  • False

9: How far from the window does a relief valve need to be according to ASHRAE-15?

  • There is no minimum for relief valve and windows.
  • At least 20'
  • At least 40'
  • At least 30'

10: The ASHRAE Standard 34 requires what type of alarm for equipment rooms using HCFC-123?

  • A group sensing
  • CO Sensing
  • refrigerant sensing
  • phosgene gas sening

11: When an electronic bridge is in balance the bridge output will be

  • 0 volts
  • .01 volts
  • 1 volt
  • 15 volts

12: What was the main reason for enacting the no venting rule of July 1, 1992?

  • Ozone depletion
  • Green house effect
  • Global warming potential
  • All of the above

13: Where are the three places that the discharge from an ammonia relief valve be piped?

  • atmosphere, tank containing water, where the A.H.J. indicates
  • underground, into drain, into mechanical room
  • to chemical neutralizing tank only
  • none of the above

14: A pressure vessel having an inside diameter of 6” or less shall be sufficient to withstand ____times the pressure of the saturation temperature of the refrigerant or ____times the critical pressure of the refrigerant, whichever is less.

  • 2.5, 3.0
  • 3.0, 3.5
  • 2.5, 2.5
  • 6.6, 6.6

15: Give an example of a secondary coolant?

  • R-12
  • R-718
  • R-410A
  • R-717

16: The location of a thermal bulb of a TXV affects

  • subcooling
  • the amount of liquid returning to the compressor
  • the amount of liquid refrigerant in the evaporator
  • the amount of liquid in the condenser.

17: Refrigerant systems containing Group I refrigerants can be installed in or on public stairways.

  • True
  • False

18: Which of the following types of oils are hygroscopic?

  • polyolester (POE)
  • polyalkylene glycol (PAG)
  • naphthene mineral
  • both a and b

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

  • Make sure its compatible, notify owner, and notify AHJ.
  • Place sign, check for leaks, and insulate suction line
  • you can never change refrigerants
  • Nothing must be done

20: 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.

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

21: Walls and doors of a machinery room shall be at least _____ hour(s) fire rated.

  • 3
  • 2
  • 1
  • 5

22: Brazed joints melt at temperatures above

  • 800F
  • 500F
  • 1,000F
  • 1,200F

23: What type of oil is used in R-410A systems?

  • polyalkylene glycol (PAG)
  • mineral oil
  • polyolester (POE)
  • naphthene

24: Low pressure chiller systems use what type of compressor?

  • Reciprocating
  • Scroll
  • Centrifugal
  • Screw

25: Total heat of a substance is considered

  • specific heat
  • enthalpy
  • empathetical
  • sensible heat