Pass Benchmark: 70% (21/30) • Standard: USCG NMC / 46 CFR
USCG Refrigeration & Air Conditioning (Set 19)
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Question 1 of 30
In a refrigeration system, the valve shown in the illustration is used for what purpose? Illustration GS-RA-14 Illustration GS-RA-14: the U.S. Coast Guard has not released this illustration.
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30 MCQs #1 In a refrigeration system, the valve shown in the illustration is used for what purpose? Illustration GS-RA-14
Illustration GS-RA-14: the U.S. Coast Guard has not released this illustration. #2 The set point adjustment of the device shown in the illustration is made by rotating what component? Illustration GS-RA-14
Illustration GS-RA-14: the U.S. Coast Guard has not released this illustration. #3 If it is necessary to increase the operating head pressure of the refrigeration system using the device shown in the illustration, what should be done? Illustration GS-RA-14
Illustration GS-RA-14: the U.S. Coast Guard has not released this illustration. #4 Which of the lettered components shown in the illustration indicates the high pressure cutout? Illustration GS-RA-12
Illustration GS-RA-12: the U.S. Coast Guard has not released this illustration. #5 When the relief valve opens on a refrigeration compressor discharge line, it discharges high-pressure refrigerant vapor to what location? #6 Alkyl benzene ISO 32 cSt synthetic refrigerant oil is miscible and suitable to use with which of the following refrigerants? #7 When checking zinc plates or pencil zincs in the refrigerating system condenser, what should you do? #8 The most cost-effective method of recovering refrigerant from a low-pressure chiller with more than 500 lbs of refrigerant and to meet EPA requirements is to recover the refrigerant using what protocol? #9 Minor repairs may be performed on low-pressure refrigerant systems without recovering the refrigerant charge if the pressure in the system is raised to atmospheric. How may this be accomplished? #10 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
Illustration GS-RA-22: the U.S. Coast Guard has not released this illustration. #11 What is one benefit of Maintenance of proper air circulation in an air conditioned cargo space? #12 In a two stage centrifugal air conditioning system, the liquid refrigerant passes through the condenser directly to what component? #13 In an air conditioning system, what is the name of the chamber where the duct-work originates? #14 A reheater in an air conditioning system performs what function? #15 The compressor used in a water-cooled air conditioning system is short-cycling. A service check determines that the suction pressure remains above the normal cut-in point during cycling and that the discharge pressure rapidly builds up to the cut-out point while running and gradually falls to the cut-in point during the off cycle. What is likely the cause? #16 When pumping down an air conditioning system to test the low-pressure cutout switch, assuming that the compressor is running, what should be done to initiate the test? #17 Using the illustrated chart giving the boiling point of moisture at various depths of vacuum, with an ambient temperature of 72°F, what depth of vacuum would be associated with the BEST chance of achieving a dehydration evacuation with a deep vacuum pump? Illustration GS-RA-56
Illustration GS-RA-56: the U.S. Coast Guard has not released this illustration. #18 When recovering the remaining R-134a refrigerant from the centrifugal chiller shown in the illustration as a vapor using the recovery unit's compressor, in addition to opening valves "1a", "1b", and the compressor suction and discharge isolation valves, which of the following would be the correct valve lineup? Illustration GS-RA-28
Illustration GS-RA-28: the U.S. Coast Guard has not released this illustration. #19 Heat is removed from the refrigerant circulating through the refrigeration system, shown in the illustration, by which component? Illustration GS-RA-12
Illustration GS-RA-12: the U.S. Coast Guard has not released this illustration. #20 A refrigeration unit will tend to short-cycle when operating under what conditions? #21 An air-cooled refrigerated container unit using R-134a as a refrigerant has a box temperature set point of -15°F, but it is currently operating with a stable return air temperature of 0°F. The fresh air makeup vent is closed, the unit is operating at 460 VAC/60 Hz, and the unit is in full capacity cool (modulating valve 100% open). Using the illustrated troubleshooting guide, what would be the normal range of expected discharge pressures if the ambient air temperature is 90°F? Illustration GS-RA-52
Illustration GS-RA-52: the U.S. Coast Guard has not released this illustration. #22 If the running suction pressure at the refrigeration compressor of a TXV controlled air-cooled refrigeration system is below normal, which of the following can be a cause? #23 What is the purpose of the pressure transducer as shown in the illustration? Illustration GS-RA-17
Illustration GS-RA-17: the U.S. Coast Guard has not released this illustration. #24 If the valve labeled "D" in the illustration is a suction service valve, what will the port labeled "7" be connected to? Illustration GS-RA-08
Illustration GS-RA-08: the U.S. Coast Guard has not released this illustration. #25 As shown in the illustrated LP centrifugal chiller pressure maintenance system, what is its functional purpose? Illustration GS-RA-40
Illustration GS-RA-40: the U.S. Coast Guard has not released this illustration. #26 Which lettered component, shown in the illustration, indicates the location of the receiver? Illustration GS-RA-12
Illustration GS-RA-12: the U.S. Coast Guard has not released this illustration. #27 As shown in the illustrated flow diagram for a self-contained recovery unit designed for the recovery of refrigerants from high pressure appliances as defined by the EPA Clean Air Act rules, what is the functional purpose of the item labeled "FS2"? Illustration GS-RA-32
Illustration GS-RA-32: the U.S. Coast Guard has not released this illustration. #28 In a refrigeration system featuring low side pump down prior to the automatic shut down of the compressor, the temperature of the refrigerated space is controlled by the action of a thermostat wired to what device? #29 Which of the following statements is true? Illustration GS-RA-12
Illustration GS-RA-12: the U.S. Coast Guard has not released this illustration. #30 A box solenoid valve used in a multi-box refrigeration system is operated by electromagnetic action by what control device?
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