Refrigeration RT/RC Prep Quiz

Topics: All categories in the pool

Quiz Result Settings

1: 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
  • 350 psig, 120 psig
  • 257 psig, 77 psig

2: Can ammonia be used on domestic system?

  • yes
  • yes, for systems under 10 tons
  • no
  • no, unless there is proper ventilation system installed

3: A check valve is a device

  • designed to allow the flow of refrigerant gas in both directions
  • that is always spring loaded
  • with a pressure drop
  • found on high pressure steam systems

4: Liquid level gauge glasses shall have automatic closing shut off valves, except Bull's eye or reflex type.

  • True
  • False

5: A machine room with a refrigerant system using ammonia shall

  • be provided with a continuously operated ventilation system
  • be considered a non-hazardous location in accordance with National Electrical code
  • have no flame producing apparatus permanently installed and operated
  • All of the above

6: A water regulating valve opens when

  • the head pressure rises
  • when the power is on there is an overcharge of refrigerant
  • the compressor is on
  • when the power is on

7: Single compound Refrigerants are classified by what two criteria?

  • Flammability and toxicity
  • Flammability and temperature range
  • Temperature range and hazardousness
  • Weight and color

8: A halide torch is most useful with a freon compression system

  • to detect refrigeration leaks in piping joints
  • to release a sticking valve
  • to remove from from TXV's and evaporator coils
  • to sweat flanges on the refrigeration piping

9: The test pressure applied to the high side of each factory-assembled refrigerating system shall be at least equal to the design pressure of

  • the low side
  • 2.5 times the design pressure
  • the aggregate of the high side and low side
  • the high side

10: The main purpose of the accumulator is to

  • provide space for vapor to accumulate
  • store liquid refrigerant
  • provide space for the accumulation of oil and containminants
  • prevent liquid slugs at the compressor

11: Refrigerants shall be classified by

  • toxicity and flammability
  • color codes
  • requirements for commercial, industrial, and residential occupancies
  • maximum permissible quantities of each group

12: Ammonia vaporization takes place at what temperature?

  • -32F
  • -28F
  • -110F
  • -460F

13: The actual expansion curve of compressor follows most nearly which one of the following

  • Isothermal
  • Volume
  • Adiabatic
  • Pressure-Temperature

14: Machinery rooms must be vented to ______?

  • neutralizing tank
  • unoccupied spaces
  • basement
  • outdoors

15: To determine the pump size needed for an open cooling tower system, the following must be known,

  • GPM and unbalanced head and friction head
  • GPM, pipe size, and equivalent head.
  • GPM and balanced head and friction head
  • GPM and friction head

16: What is the purpose of a surge capacitor on a contactor?

  • to balance the sine waves
  • to provide smoother start/stops
  • to keep the contactor pulled in
  • to protect low voltage equipment

17: Indirect systems using Group II refrigerants

  • shall be used in refrigeration system in excess of 1,000 lbs
  • shall be used in refrigeration system less than 1,000 lbs
  • shall be used for mechanical equipment only
  • shall have all refrigerant containing parts except piping, installed in a Class T machine room

18: 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

19: Before replacing a seized compressor, the _______ should be determinded.

  • designed head pressure
  • cause of seizure
  • type of refrigerant
  • current draw

20: Refrigerant piping crossing an open space that affords passageway in any building shall not be less than _____ feet above the floor unless piping is located against the ceiling.

  • 7.00'
  • 8'4"
  • 9.00'
  • 7.25'

21: pressure relief valves must discharge to the atmosphere at a location not less than 15 feet from ground level and ____ feet from any window, ventilation opening, or exits of buildings.

  • 10
  • 20
  • 25
  • 15

22: Relief valves are rated in

  • gallons of water per hour
  • pounds of air per hour
  • pounds of air per minute
  • gallons of water per minute

23: 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

24: Where can 50/50 solder be used on?

  • suction line
  • liquid line
  • discharge line
  • none of the above

25: 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

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