Refrigeration RT/RC Prep Quiz

Topics: All categories in the pool

Quiz Result Settings

1: What refrigerant doesn't have to be classified?

  • R-717
  • R-422A
  • R-134A
  • R-718

2: What must be done to refrigerant pipes before being buried ?(8.10.4)

  • Leak checked
  • Insulated and installed in a pipe duct (Encased)
  • Classifed
  • Certified

3: When should a relief valve start to function?

  • Two times it's working pressure
  • Before the purge station discharges
  • At it's set pressure
  • 10 psi before it's set pressure

4: A self contained system

  • is any system or part of a system used to increase evaporation by expansion or vaporization
  • is a unit system Group I refrigerants only
  • is a complete factory made and tested system
  • is a unit system Group II refrigerants only

5: What's the purpose of a megohmmeter?

  • To measure low to very low resistance values
  • To alternate the current in a DC circuit in order to calculate the total impedance of a circuit
  • To measure very high resistances
  • None of the above

6: When is the only time you can leave a service container attached to a system?

  • Leaking system
  • Recovery
  • Charging
  • Both b and c

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: High pressure controls should be set no higher than

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

9: Defined process piping by code CMR (528)

  • Any piping that conveys a solid, liquid or gas that is not part of the plumbing or fire protection system
  • Any piping in an industrial space
  • Any piping in an industrial or commercial space
  • All of the above

10: On cooling towers, what causes the condenser water to drop

  • sensible heat
  • tower fans
  • evaporation of the water droplets
  • ambient temperatures

11: Clearance volume

  • has no effect on compressor capacity
  • is the same on all compressors
  • affects compressor capacity
  • varies depending on compressor speed

12: Ammonia can come in contact with _______ ?

  • Copper
  • Aluminum
  • Brass
  • Copper tubing

13: Pressure limiting devices are not required for systems containing less then ________ refrigerants.

  • 6.6 lbs
  • 13.9 lbs
  • 22 lbs
  • 44 lbs

14: Class A refrigerants are considered

  • toxic
  • flammable
  • non-flammable
  • non-toxic

15: How does a centrifugal compressor create the pressure differential needed to move refrigerant through the system?

  • Nesting scrolls
  • Fan-like action
  • Rotating vanes
  • Suction and discharge valves

16: The certificate of inspection

  • shall be $20 and an additional fee of $1 for each tone above 20 tons
  • shall be posted on the compressor shell or electrical panel at the unit
  • shall be authorized by a notarized insurance company
  • shall be posted and protected from dirt, water, and other elements

17: What instrument is used to measure very high resistance?

  • voltmeter
  • tape measure
  • meg ohmmeter
  • ammeter

18: Megaohm meter's main function is

  • to detect weak motor winding insulation of a refrigeration or air conditioning compressor by creating high DC voltages to the compressor
  • to detect very high resistances to ground of refrigeration or air conditioning compressors
  • to test very high value capacitors for large 3-phase refrigeration compressors and blower motors.
  • Both a and b are correct

19: Low temperature systems should have what?

  • High pour point
  • Low pour point
  • High viscosity
  • None of the above

20: Oils, classified as to source, are

  • animal, vegetable, and castor
  • naphthalene, paraffin, and castor
  • animal, vegetable, and mineral
  • naphthalene, mixed, and paraffin

21: The solution that is pumped into the concentrator in an absorption chiller is referred to as the

  • absorbed solution
  • weak solution
  • strong solution
  • concentrated solution

22: 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
  • 257 psig, 77 psig
  • 350 psig, 120 psig
  • 226 psig, 68 psig

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

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

24: If the suction pressure is low and the evaporator temperature high, the cause will be a?

  • compressor suction valve stuck open
  • overcharged
  • starved evaporator
  • too small evaporator

25: Which refrigerant class listed below is the most flammable?

  • B-2
  • A-1
  • A-3
  • C-3