Assessment Test

Warning: mysql_connect(): Access denied for user 'lorque_wrdp1'@'localhost' (using password: YES) in /home/tmc2018/ on line 15

1. Excessive moisture being collected in the purge unit of a low pressure refrigeration system could indicate which probable condition?


2. An evaporator coil of a single evaporator, air cooled refrigerator is accumulating excessive frost due to a failure of the defrost mechanism. If the refrigerator features a thermostatically controlled box solenoid and a low pressure cutout controlled compressor, as well as a high pressure cutout, in terms of the compressor, what would be the most likely operating symptom?


3. In a low pressure refrigeration system, excessive running of the purge recovery unit generally indicates which probable condition?


4. Which recovery procedure should be used to minimize the loss of oil from the system during the recovery of refrigerant from small appliances such as a water cooler?


5. What is true concerning highly contaminated refrigerant recovered from burned out small appliances?


6. Technicians servicing small refrigeration appliances can employ what type of recovery equipment?


7. If passive recovery is used on a small appliance fitted with a capillary tube as a metering device with a non-operating compressor, the recovery should be made through what means?


8. 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?


9. The most cost-effective method of recovering refrigerant from a low pressure chiller with more than 500 lbs of refrigerant and to meet Environmental Protection Agency (EPA) requirements is to recover the refrigerant using what protocol?


10. Why is a purge recovery unit typically fitted on low pressure centrifugal chillers?


11. How should small appliances with less than three pounds of refrigerant be charged with refrigerant?


12. Charging liquid HCFC-123 into a system under a deep vacuum could cause what to happen unless necessary precautions are taken?


13. When a refrigeration system is being topped off with a small amount of refrigerant through the low side with the compressor running, what should be done?


14. Which of the valves listed is normally closed when charging the refrigeration system through the high side?


15. For safe storage, the maximum allowable temperature to which refrigerant bottles should be exposed is what temperature?


16. Overfilling a refrigerant container is extremely dangerous because of the high pressures generated. The generation of pressure is the result of what?


17. Personnel servicing refrigeration systems and subject to the exposure to commonly used refrigerants should wear what type of personal protective equipment?


18. In the presence of an open flame or hot surfaces, chlorinated fluorocarbon refrigerants decomposes and form what chemical substance?


19. Why can CFC or HCFC refrigerants leaking into a confined space or in limited surroundings cause suffocation?


20. What is the purpose of running a refrigeration compressor in short intermittent spurts or throttling the suction isolation valve when starting the system after a prolonged shutdown?


21. When starting a reciprocating refrigeration compressor that has been shut down for a period of time, you should manually throttle which valve?


22. When opening or closing compressor service and line isolation valves on a typical refrigeration system that is fitted with packed valves, what must you do?


23. In an air conditioning system, what is the name of the chamber where the duct-work originates?


24. In a two stage centrifugal air conditioning system, the liquid refrigerant passes through the condenser directly to what component?


25. A reheater in an air conditioning system performs what function?


26. What is one benefit of Maintenance of proper air circulation in an air conditioned cargo space?


27. In general, the thermal bulb for a thermal expansion valve used in a reciprocating air conditioning system is usually charged with what substance?


28. To prevent the unnecessary loading of an air conditioning system while maintaining the designed dry bulb temperature and relative humidity in an air conditioning system, what should be done?


29. Which of the following methods is normally used to control the circulated air temperature of an air conditioning system using chilled water circulation?


30. For the proper control of the air temperature in an air conditioning system using chilled water circulation, which of the listed conditions should remain constant regardless of load changes?


31. Which of the processes listed would be the most satisfactory method to use to lower the humidity of the air being circulated by an air conditioning system?


32. A room humidistat initiates the lowering of the humidity of the conditioned supply air to a space, while the actual process is accomplished by what means?


33. In an air conditioning system, moisture is removed from the air by what means?


34. To add small amounts of refrigerant to the low side of an air conditioning system, the refrigerant should be introduced through a particular valve and in a particular state. What valve and state combination is correct


35. To add refrigerant to the high side of an air conditioning system, you should close the king valve and introduce the refrigerant through what valve in what state?


36. 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?


37. 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?


38. The surging that occurs in a centrifugal air conditioning compressor is a result of what conditions?


39. In an air conditioning system, low discharge head pressure associated with a reciprocating compressor can be the result of what condition?


40. Coast Guard Regulations (46 CFR Part 58) require a method for the relieving pressure of an over pressurized refrigeration system. Which of the following statements complies with these Regulations?


41. Coast Guard Regulations (46 CFR Part 113) require refrigerated spaces that can be locked from the outside and that cannot be opened from the inside to have an audible alarm. Where is the audible alarm required to be?


42. With regards to shipboard refrigeration systems, after July 1, 1992, what action became illegal?


43. Refillable tanks used to ship CFC and HCFC refrigerants or used to recover these refrigerants must meet the standards of what entity?


44. According to 46 CFR, Part 58, for protection purposes, what is required of all refrigeration systems?


45. What would be an example of a small appliance as defined in the EPA Clean Air Act rules?


46. Which best defines a "Type I" small refrigeration appliance according to the EPA Regulations Section 608?


47. 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?


48. EPA Clean Air Act rules permit refrigerant to be released to the atmosphere under which of the following conditions?


49. 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?


50. 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?


51. Persons recovering refrigerant from small appliances must be certified as what type of technician under the EPA Clean Air Act rules?


52. 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?


53. 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?


54. What type of HVAC system is ideally designed to serve a large public space?


55. What type of HVAC system is characterized by poor air distribution and ventilation and low system heat loads?


56. What type of HVAC system is characterized by a having a split supply air stream, with one for cold air and the other for hot air?


57. What type of HVAC system is characterized by having control dampers in locations other than the outside air supply, outside air exhaust, and recirculation damper applications?


58. What type of pump is invariably used as a circulator in a hydronic heating system?


59. What statement is true concerning a one-pipe hydronic heating system?


60. It is absolutely essential that hydronic heating system hot water piping be kept free of air. Assuming that a system is initially properly filled with water, what is the primary source of air contamination?


61. What advantage does a 4-pipe hydronic heating/cooling heating system have over a 2-pipe hydronic heating/cooling system?


62. Concerning cargo-hold dehumidification, what statement is true?


63. What statement is true concerning a liquid desiccant cargo-hold dehumidification system?


64. What statement is true concerning a liquid desiccant cargo-hold dehumidification system?


65. With regard to the cooling and heating coils and humidification and regeneration chambers of a liquid cargo-hold dehumidification system, what statement is true?


66. To prevent damage to dry cargoes, the cargo hold ventilation and dehumidification systems play a key role. In terms of the maintained dew point, what statement is true?


67. To determine the average cargo hold dew point temperature, at what location would the dew point be measured?


68. What temperature associated with the psychrometric properties of air is measured by an ordinary thermometer?


69. 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?


70. A refrigeration unit will tend to short cycle when operating under what conditions?


71. If a refrigeration compressor had developed a slightly high suction pressure accompanied with an abnormally low suction temperature, the problem could be a result of which of the following?


72. 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?


73. If a refrigeration compressor using a thermostat as a primary controller is running continuously without significantly lowering the temperature in the refrigerated space, which of the following is most likely the trouble?


74. Moisture in a refrigeration system can cause which of the following conditions?


Total Rating:

click here to go to review now