Refrigeration RT/RC Prep Quiz

Topics: All categories in the pool

Quiz Result Settings

1: The maximum permissible amperage draw for a 40VA transfomer with a secondary voltage of 24V is

  • 1.2
  • .8
  • .1
  • 1.7

2: Two capacitors are wired in parallel. One capacitor has a value of 15uf. The other has a value of 25uf. What is the total value supplied?

  • 25 uf
  • 40 uf
  • 15 uf
  • 20 uf

3: Thermodynamics is the branch of science that deals with

  • molecular therory
  • state of energy
  • heat energy
  • energy due to motion

4: Which of the following most closely represents the concentration of Li-Br in a absorption system?

  • 60% Li-Br, 40% distilled water
  • 50% Li-Br, 50% tap water
  • 40% Li-Br, 60% tap water
  • 40% Li-Br, 60% distilled water

5: A chiller entering and leaving temperature difference is?

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

6: Suction valve unloaders afford an effective means of

  • capacity control
  • refrigerant control
  • evaporator control
  • superheat control

7: What type of voltage causes the winding in a potential relay to open?

  • BEMF (Back Electro-Motive Force)
  • 24V control voltage from the thermostat
  • 120V line voltage
  • None of the above

8: Lithium-bromide, Li-Br, is best characterized as a

  • soil
  • sugar
  • sand
  • salt

9: What is the typical air conditioning operating pressures for R-22?

  • 60 psi suction 210 psi discharge
  • 25 psi suction 125 psi discharge
  • 105 psi suction 340 psi discharge
  • None of the above

10: A Low-Probability System

  • is such that a leak of refrigerant from a failed connection can not enter the occupied space
  • is such that any leak will cause injury or death to anyone within a 100 square foot area
  • is such that a leak of refrigerant from a failed connection will enter the occupied space
  • is a system highly likely to leak form a failed connection or component of such system

11: Stop valves shall not be permitted between the system and the

  • condenser
  • service valve
  • relief valve
  • bleed valve

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

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

13: A compressor that increases vapor pressure by changing the internal volume of the compression chamber is called?

  • Positive displacement
  • Non-positive displacement
  • Low Pressure displacement
  • Pressure induced displacement.

14: R-22 is classified as a ____ refrigerant on the safety matrix.

  • A-1
  • B-1
  • A-2
  • B-2

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

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

16: How many opening forces operate a thermostatic expansion valve?

  • 4
  • 2
  • 1
  • 3

17: How many flammability classifications are refrigerants in?

  • 3
  • 7
  • 2
  • 5

18: How many different groups of refrigerants are there?

  • 3
  • 11
  • 15
  • 7

19: Booster compressors, pump refrigerant into the

  • heat & plate heat exchanges
  • receiver
  • high side of the secondary compressor
  • low side of the primary compressor

20: Cooling tower lowers condenser water temp by

  • evaporative cooling
  • running fans at 100%
  • running water thru a secondary heat exchanger
  • condensation

21: A R-410A system running with a condensing temperature of 110F and 50F evaporator temperature will read pressures of ___ on the high side and ___ on the low side

  • 455 psig, 185 psig.
  • 257 psig, 77 psig
  • 226 psig, 68 psig
  • 365 psig, 120 psig

22: The main purpose of a refrigerant detector in a machinery room is to

  • inform there is a refrigerant leak int he system
  • detect toxins in the air caused by a refrigerant leak
  • to set off an alarm when there is refrigerant present inside the room
  • all of the above

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

  • Stay open
  • Under feed
  • Over feed
  • Close

24: copper and its alloys shall not be used in contact with _____ except as a component of bronze alloys for bearing or other non-refrigerant containing uses.

  • HCFC-123
  • Lithium bromide
  • ammonia
  • CFC-11

25: What is the voltage of each leg of a 480 Volt three-phase motor?

  • 240v
  • 120v
  • 208v
  • 277v