Refrigeration RT/RC Prep Quiz

Topics: All categories in the pool

Quiz Result Settings

1: Ammonia vaporization takes place at what temperature?

  • -460F
  • -32F
  • -28F
  • -110F

2: A start capacitor is wired in _____ with the start windings.

  • series-parallel
  • series
  • parallel
  • junction

3: Suction line oil traps should be installed when the condenser is

  • on the third floor roof and the evaporator is in the basement
  • located outside the operates in temperatures below 35F
  • more than 100' away from the evaporator
  • in the basement and the evaporator is on the third floor

4: Liquid refrigerant flashing, or turning to vapor, in the liquid line may be due to

  • liquid line that is too small
  • shortage of refrigerant
  • liquid line that had too high vertical lift
  • All of the above

5: An electronic bridge circuit is basically a

  • 24 volt control circuit
  • Wheatstone
  • high voltage circuit
  • suspension

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

  • relief valve
  • condenser
  • service valve
  • bleed valve

7: Fusible plugs must have what marked on them?

  • Melting temperature in F
  • Melting temperature in C
  • Opening pressure
  • All of the above

8: Cooling tower lowers condenser water temp by

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

9: Name a CFC refrigerant(s):

  • R-11
  • R-12
  • R-123
  • both a & b

10: The purpose of an accumulator is to

  • reduce friction loss to the flow of refrigerant
  • assure no liquid returns to the compressor
  • store excess refrigerant from the reciver
  • filter out impurities from the system

11: Institutional occupancy is

  • a premise or that portion of a premise where large numbers of people congregate and from which occupants cannot quickly vacate the space.
  • a premise or that portion of a premise from which, because they are disabled, debilitated, or confined, occupants cannot readily leave without the assistance of others.
  • a premise or that portion of a premise where people transact business, receive personal service, or purchase food and other goods.
  • None of the above

12: The instrument used to measure the specific gravity of absorption chiller solutions is the

  • hydrometer
  • Psychrometer
  • anemometer
  • refractometer

13: High pressure controls should be set no higher than

  • 90% of set point
  • 80% of set point
  • 25% of set point
  • 10% of set point

14: A direct system

  • is one which encloses a separate body of evaporative refrigerant
  • is a self-contained complete factory made and tested system
  • is where the refrigerant comes in contact with the space refrigerated
  • is on where brine is cooled & circulated to the space refrigerated

15: Ammonia is under what safety classification?

  • B1
  • A3
  • B2
  • B3

16: What is the boiling point of refrigerant governed by?

  • Compressor RPM's
  • P&T relationship
  • Evaporator temperature
  • Condenser sub-cooling

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

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

18: If a halide torch is used for leak detection, what color is the flame if it detects a leak?

  • green
  • red
  • orange
  • blue

19: What is absolute humidity?

  • the amount of moisture in the air per one pound of 50% RH air
  • the amount of moisture in the air in grains of cubic feet of volume
  • the amount of moisture in the air in grains of square feet of volume
  • none of the above

20: Calculate the voltage in a series circuit when the total amperage is 10 amps and the resistors have values of: R1=12 ohms, R2=8 ohms, R3=4 ohms

  • 240 volts
  • 2.40 volts
  • 24.0 volts
  • 2,400 volts

21: If the spring is adjusted to increase the superheat, this new setting will

  • shorten the frost line
  • have no effect on the frost line
  • allow more liquid into the evaporator
  • lengthen the frost line

22: A class B2 refrigerant is considered

  • non-toxic and highly flammable
  • toxic and somewhat flammable
  • non-toxic and non-flammable
  • toxic and non-flammable

23: All electrical work done on refrigeration systems must comply with

  • OSHA
  • ASHREA-15 Section 9.2.1
  • NEC and Massachusetts Modifications
  • Department of Energy

24: What type of fuses must be used on a HVAC system?

  • TR Type, Duel Element, Time Delay
  • Fast blow
  • 10% lower than RLA
  • none of the above

25: At higher altitudes, boiling temperatures

  • depends on the refrigerant
  • are unaffected
  • decrease
  • increase