Pass Benchmark: 70% • Standard: USCG NMC / 46 CFR
USCG Engine Refrigeration (Supplementary) (Set 6)
30:00
|Question 1 of 30
Question Navigator
Correct Incorrect Pending Starred
Question 1 of 30
EPA Clean Air Act rules permit refrigerant to be released to the atmosphere under which of the following conditions?
Browse Questions in Set 6
30 MCQs #1 EPA Clean Air Act rules permit refrigerant to be released to the atmosphere under which of the following conditions? #2 When recovering R-12 from a small appliance with a working compressor, using a recovery device manufactured after November 15, 1993, what percentage of the remaining charge must be removed from the system? #3 According to the EPA Clean Air Act rules, what is true concerning refrigerant leaks in a small hermetically sealed shipboard water cooler with a 20 ounce charge weight? #4 In the presence of an open flame or hot surfaces, chlorinated fluorocarbon refrigerants decomposes and form what chemical substance? #5 Which of the following statements is true concerning the gauge labeled "A" of the illustrated gauge manifold set? GS-RA-01 #6 Which of the following statements is true concerning the illustrated gauge manifold set? GS-RA-01 #7 Which of the illustrated gauges is capable of measuring vacuums at the micron level for the purpose of proving system dehydration during system evacuation with a vacuum pump, but displays the achieved vacuums at incremental threshold intervals rather than continuously. Illustration GS-RA-37 #8 The introduction of outside air to the air conditioning system is 90°F with a relative humidity of 60%. The air has been conditioned to 70°F with a relative humidity of 80%. Using the psychrometric chart, shown in the illustration, determine the quantity of moisture removed from one pound of the conditioned air. See Illustration GS-RA-22
Illustration GS-RA-22: the U.S. Coast Guard has not released this illustration. #9 Which of the following is true concerning the class "D" air conditioning system shown in the following illustration? Refer to Illustration GS-RA-42
Illustration GS-RA-42: the U.S. Coast Guard has not released this illustration. #10 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? #11 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. #12 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. #13 The air temperature associated with a direct reciprocating air conditioning plant is found to be too warm, and the compressor is not operating. A service check determines the compressor suction pressure to be above the normal cut-in point, with a normal head pressure, and high evaporator superheat. Which of the following could be the cause of this problem? #14 Alkylbenzene ISO 32 cSt synthetic refrigerant oil is miscible and suitable to use with which of the following refrigerants? #15 What is the color coding for a storage container of R-134a refrigerant? #16 In the illustrated refrigeration system, what is the proper name for the component labeled "A"? GS-RA-12
Illustration GS-RA-12: the U.S. Coast Guard has not released this illustration. #17 What is the drive arrangement of refrigeration compressor shown in figure "B" of the illustration? GS-RA-41 #18 A refrigeration unit will tend to short cycle when operating under what conditions? #19 A box solenoid valve used in a multi-box refrigeration system is operated by electro- magnetic action by what control device? #20 Which of the following electrically operated refrigeration system valves would be most appropriate for use as a 2 position diverting hot gas bypass solenoid valve? GS-RA-19
Illustration GS-RA-19: the U.S. Coast Guard has not released this illustration. #21 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? #22 Which of the following statements is true? GS-RA-12
Illustration GS-RA-12: the U.S. Coast Guard has not released this illustration. #23 A container unit's microprocessor-controlled temperature controller is set at -28.9 ° C, appropriate for a frozen cargo of ice cream. In this mode of operation, according to the illustrated temperature controller functional diagrams, what should be the operational status of the unit if the actual box temperature is -18.0 ° C? GS-RA-035
Illustration GS-RA-035: the U.S. Coast Guard has not released this illustration. #24 The low pressure cutout switch settings vary with the refrigerant used and the temperature application. If the low pressure cutout switch for a particular application is set with a cut- in pressure of 5 psig, what would be the cut-out pressure if the differential is 7.5 psig? #25 The fluid used as a source of actuating power against the underside of the unloader power element piston of the refrigeration compressor capacity control mechanism illustrated is obtained from where? GS-RA-13
Illustration GS-RA-13: the U.S. Coast Guard has not released this illustration. #26 During operating periods of a multi-box refrigeration system using a capacity controlled compressor, when all of the evaporators of a four box plant are actively being fed with liquid refrigerant, the control oil pressure acting on the hydraulic relay piston will be at what value? GS-RA-13
Illustration GS-RA-13: the U.S. Coast Guard has not released this illustration. #27 A refrigeration compressor used in a multi-box refrigeration system, is designed with six of its eight cylinders able to be controlled for variable load conditions. If all of the reefer boxes are currently feeding, what percentage of the total number of compressor cylinders will be loaded after start up? #28 As shown in the illustrated refrigeration system piping schematic diagram with the various accessories and controls and equipped with an air-cooled condenser with high side pressure controls, what statement is true concerning the fan cycling control pressure switch? GS-RA-39
Illustration GS-RA-39: the U.S. Coast Guard has not released this illustration. #29 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? GS-RA-14
Illustration GS-RA-14: the U.S. Coast Guard has not released this illustration. #30 In a refrigeration system, the valve shown in the illustration is used for what purpose? GS-RA-14
Illustration GS-RA-14: the U.S. Coast Guard has not released this illustration.
Question Discussion & Notes
0Have a doubt, memory trick, or exam update? Share your insights with fellow mariners.
Loading mariner discussions...