Pass Benchmark: 70% (21/30) • Standard: USCG NMC / 46 CFR
USCG Refrigeration & Air Conditioning (Set 8)
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Question 1 of 30
Concerning the arrangement of equipment and associated hoses shown in the illustration, what statement is true? Illustration GS-RA-58 Illustration GS-RA-58: the U.S. Coast Guard has not released this illustration.
Browse Questions in Set 8
30 MCQs #1 Concerning the arrangement of equipment and associated hoses shown in the illustration, what statement is true? Illustration GS-RA-58
Illustration GS-RA-58: the U.S. Coast Guard has not released this illustration. #2 The surging that occurs in a centrifugal air conditioning compressor is a result of what conditions? #3 In an air conditioning system, low discharge head pressure associated with a reciprocating compressor can be the result of what condition? #4 Sludge may form in the crankcase of an air conditioning compressor as a result of what condition? #5 As shown in the illustrated LP centrifugal chiller high efficiency purge recovery unit piping schematic, what statement is true concerning the vacuum pump? Illustration GS-RA-55
Illustration GS-RA-55: the U.S. Coast Guard has not released this illustration. #6 Traditionally, which of the listed refrigerants has been more suitable than the others for use in a centrifugal refrigeration compressor? #7 Which of the fluids listed is suitable for use as a secondary refrigerant? #8 The amount of HCFC-123 in a storage cylinder is measured by what means? #9 Which of the following substances is normally classified as a low pressure refrigerant? #10 The gas that exists in the stratosphere forming a protective shield that helps to protect the environment from the harmful effects ultraviolet radiation is called what? #11 The "tare weight" of a refrigerant storage cylinder refers to what weight? #12 The safety heads of most large reciprocating compressors used in refrigeration systems are held in place by what means? #13 A device used to hold open the refrigeration compressor suction valve during starting to reduce the compression load is called what? #14 The carbon seal ring of a refrigeration compressor crankshaft mechanical seal is held in position against the stationary ring face by using what device? #15 If the discharge reed valves used in a refrigeration compressor are leaking badly, what statement is true? #16 In addition to the drive belt itself, a V-belt that is tensioned too tight will cause excessive wear to what other drive component? #17 When one belt of a multiple V-belt drive requires replacing, what will be required? #18 Excessively tight drive belts installed between a motor and a refrigeration compressor pulley may cause what condition? #19 When installing a mechanical shaft seal on a refrigeration compressor, extreme care must be taken to prevent what from happening? #20 If a refrigeration system were short of refrigerant, besides an elevated box temperature, what would be an observable symptom? #21 A reciprocating refrigeration compressor may be tested for leaking discharge valves by stopping the compressor, turning the discharge service valve all the way in, and then turning the compressor over by hand. If the discharge valves are leaking, the compound gage will show pressures which react in which way? #22 Which of the conditions listed could cause excessively low refrigerant pressure at the compressor suction of a TXV controlled refrigeration system? #23 Low compressor head pressure in a refrigeration system can be caused by which of the following? #24 An excessive charge of refrigerant in a thermostatically controlled, air-cooled, refrigeration system using a TXV as an expansion device can cause which of the following? #25 In an operating, water-cooled, multi-box refrigeration system, both low discharge and high suction pressures are being simultaneously experienced. The probable cause for this condition is which of the following? #26 If a refrigeration system, equipped with a reciprocating compressor, has a liquid-line solenoid valve that is leaking during the 'off' cycle, what would this cause? #27 Unusual noise coming from a refrigeration compressor can be caused by which of the following conditions? #28 Which of the listed statements describes the reason why oil foaming occurs when starting a refrigeration compressor? #29 If a refrigeration compressor were short cycling on the low pressure cutout switch, what is the most probable cause? #30 In a multi-evaporator refrigeration system, a solenoid valve is installed in the liquid line prior to what device?
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