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Test Bank For Modern Refrigeration and Air Conditioning 21st Edition by Andrew 2
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Test Bank For Modern Refrigeration and AirConditioning 21st Edition by Andrew D. Althouse, Carl
H. Turnquist, Alfred F. Bracciano, Daniel C. Bracciano,
Gloria M. Bracciano
1. When repairing a refrigeration system, a swaging tool set would be used to carry
out which of the following operations? - ANSWER Swaging tools can be used to
expand an end of one tube to fit onto a tube of the same original outside diameter.
2. In a refrigeration system that is not protected by a water failure switch, if the
cooling water to the condenser fails, what will be the result for protective purposes? -
ANSWER the compressor will shut down by the action of the high-pressure cutout
switch
3. When the relief valve opens on a refrigeration compressor discharge line, it
discharges high-pressure refrigerant vapor to what location? - ANSWER suction
side of the compressor
4. Which of the lettered components shown in the illustration indicates the high-
pressure cutout? Illustration GS-RA-12 - ANSWER X
5. The rupture disc on a low-pressure centrifugal refrigeration unit is used as an
overpressure protection device and is set to relieve at 15 psig and is most likely to lift
when the compressor is idle. Where is the rupture disc located? - ANSWER on top
of chiller evaporator shell
6. During the initial cooling down of a box temperature in a refrigeration system,
which of the devices listed is used to prevent excessive gas pressure at the
compressor suction for the purpose of prevention of overloading of the compressor
driver? - ANSWER Crankcase pressure regulator
7. A reheater in an air conditioning system performs what function? - ANSWER
restores the conditioned air temperature to a comfortable level
8. What is one benefit of maintenance of proper air circulation in an air conditioned
cargo space? - ANSWER reduced slime and mold
9. In a two stage centrifugal air conditioning system, the liquid refrigerant passes
through the condenser directly to what component? - ANSWER economizer
10. In an air conditioning system, what is the name of the chamber where the duct-
work originates? - ANSWER plenum chamber
,11. What is the wet bulb temperature of air if the dry bulb temperature of the air is 90
degrees and the relative humidity is 65%? Illustration GS-RA-22 - ANSWER 80
degrees F
12. In general, the thermal bulb for a thermal expansion valve used in a reciprocating
air conditioning system is usually charged with what substance? - ANSWER the
same refrigerant as the system
13. Heat is removed from the refrigerant circulating through the refrigeration system,
shown in the illustration, by which component? Illustration GS-RA-12 - ANSWER B
14. Sea water or low temperature central fresh water is typically provided to a ship's
stores refrigeration plant for what purpose? - ANSWER condense the refrigerant
gas
15. Zinc plates commonly found in refrigeration systems and used as sacrificial
anodes are located where? - ANSWER salt water side of the condenser
16. Vapor bubbles present in the liquid upon arrival to the thermal expansion valve in
a refrigeration system may cause erosion of the expansion valve's needle and seat.
This, in turn, could cause what condition? - ANSWER TXV hunting
17. Moisture entering a typical refrigeration system will most likely produce what
effect? - ANSWER freeze in the expansion valve
18. A small obstruction at the thermostatic expansion valve inlet will result in which of
the following conditions? - ANSWER Lower than normal suction pressure.
19. An obstructed expansion valve may be indicated by an incompletely cooled
evaporator and what other symptom? - ANSWER frosting at the evaporator inlet
20. Which of the following conditions will occur if the power element of the
thermostatic expansion valve shown in the illustration loses its charge? Illustration
GS RA-07 - ANSWER The valve will fail closed, providing no cooling capacity.
21. If the needle and seat assembly is excessively eroded, the valve cage assembly
can be replaced. In replacing the original valve cage assembly rated at 1/2 tons,
what would be the result if the replacement valve cage was oversized at 5 tons?
Illustration GS-RA-07 - ANSWER The expansion valve would hunt excessively,
alternately starving and overfeeding the evaporator coil.
22. If the superheat value of the thermostatic expansion valve is adjusted too high,
what would be the result? - ANSWER the suction line of the compressor will be
abnormally warm
23. If the superheat setting of a thermostatic expansion valve is set too low, what
would be the result, assuming that the system has a single evaporator? - ANSWER
the suction line will be abnormally cold and liquid may flood back to the compressor
, 24. Which of the illustrated valves is used to gain access to a hermetic system and
features a Schrader core valve which is unseated by the core depressor of hose
fitting when attached? Illustration GS-RA-69 - ANSWER D
25. How should small appliances with less than three pounds of refrigerant be
charged with refrigerant? - ANSWER vapor charged
26. Before charging a refrigeration unit, unless quick disconnect fittings are used, the
refrigerant charging hoses should be prepared in what way? - ANSWER they
should be purged with refrigerant
27. Which of the illustrated devices would be the LEAST accurate for the purposes of
weighing-in a refrigerant charge? Illustration GS-RA-45 - ANSWER C
28. Concerning the charging of refrigerant into a vapor compression refrigerating
system, which of the following is true? - ANSWER when charging as a liquid it
should be to the high side only
29. Which of the following illustrated expansion valves is designed to maintain a
constant evaporator pressure rather than a constant evaporator superheat?
Illustration GS-RA-24 - ANSWER C
30. Within the territorial limits of the United States, violations of the Clean Air Act of
1990, that includes the intentional release of R-11, R-12, R-22 and other related
class I or class II substances may result in fines for each violation per day of what
amount? - ANSWER $25,000
31. All shipboard personnel responsible for the maintenance and repair of air
conditioning systems using refrigerants covered under the EPA Clean Air Act venting
prohibition, must be certified through an approved Environmental Protection Agency
(EPA) program to do which of the following? - ANSWER before performing
maintenance, service or repair that could reasonably be expected to release Class 1
or Class 2 refrigerants into the atmosphere
32. Persons recovering refrigerant from small appliances must be certified as what
type of technician under the EPA Clean Air Act rules? - ANSWER Type I or
Universal technician
33. What would be an example of a small appliance as defined in the EPA Clean Air
Act rules? - ANSWER a hermetically sealed water cooler with a 2 lb. refrigerant
charge
34. If you find the pressure of a refrigeration system containing a Class I or Class II
refrigerant to be opened for the accomplishment of repairs is 0 psig, what must be
done? - ANSWER do not attempt to recover any refrigerant and repair the leak
before pulling a vacuum on the system
35. Excessively tight drive belts installed between a motor and a refrigeration
compressor pulley may cause what condition? - ANSWER premature wear of both
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