ESCO Light Commercial Refrigeration EXAM Questions and Answers, Exams of Nursing

Download ESCO Light Commercial Refrigeration EXAM Questions and Answers and more Exams Nursing in PDF only on Docsity! ESCO Light Commercial Refrigeration EXAM In a dry type (direct expansion) evaporator, liquid refrigerant must boil away as close to the end of the coil as possible in order to: - Answer The difference between the temperature of the refrigerant boiling in the evaporator and the temperature at theevaporator outlet is known as: - Answer An expansion device that is stuck open will cause: - Answer When measuring evaporator superheat on a commercial system that has a long suction line, the pressure reading should be taken at the: - Answer Superheat measurements are best taken: - Answer Atechnician is checking the superheat on a multi-circuit evaporator and finds one of the circuits has a superheat that is higher than the others. This could be caused by: - Answer A TEV with an external equalizer is used on: - Answer Dry type evaporators operate most efficiently with a superheat setting of approximately: - Answer An evaporator used to chill liquids si operating with a normal superheat setting, but the system is not cooling the product properly. Which of the following is the most likely cause? - Answer What time interval is required between each superheat adjustment? - Answer Alow temperature evaporator used for cooling space or product refrigeration: - Answer Some special applications use aflooded evaporator (operated full of refrigerant). nI order to maintain the proper level of liquid refrigerant, a type metering device is used. - Answer A properly functioning condenser will first; - Answer The effect of an inefficient water cooled condenser will; - Answer The refrigerant condensing temperature in a water cooled condenser is normally about higher than the leaving water. - Answer The refrigerant in an air cooled condenser will normally condense at approximately higher temperature than the air passing over it. - Answer Workable head pressure during periods of lowambient temperature can be achieved by using; - Answer Cooling towers that pass air over water to remove system heat are limited in capacity by: - Answer Parallel compressors often referred to as a rack system may use; - Answer The major difference between a cooling tower and an evaporative condenser is: - Answer " Pump Down" means to capture system refrigerant in the : - Answer What is the normal operating position for a compressor service valve? - Answer The suction accumulator prevents flood back from which of the following: - Answer When a compressor service valve si back seated, which port is closed? - Answer When work on a refrigeration system is complete, the compressor service valves should be in this position: - Answer What type of oil is used with HFC refrigerant? - Answer On an expansion valve refrigeration system, a low pressure control can indirectly be used for: - Answer What valve is used to connect multiple evaporators of different temperatures to a single compressor? - Answer What valve is used to prevent evaporator pressure from fallingbelow a-set limit? - Answer What valve is used to control excessive pressure entering the compressor during a hot pull down? - Answer The oil return orifice inside a suction line accumulator is designed to: - Answer Why do suction line filter driers have two service ports? - Answer Athermostatic expansion valve (TV) that creates an unstable suction pressure si said to be: - Answer Head pressure control valves permit hot gas to travel directly to: - Answer Liquid slugging of the compressor can becaused by: - Answer A-severe evaporator freeze-up may cause: - Answer The oil separator is installed in the: - Answer If an oil separator is not used: - Answer If a system has a long suction line riser an oil trap should be installed; - Answer The relationship between low-side absolute pressure and high-side absolute pressure is called: - Answer Capacity control of a large compressor can be performed with: - Answer Vibration eliminators should be installed_________to the compressor crankshaft centerline. - Answer What (Ph) level is considered neutral and desired for ice machine or cooling towers applications; - Answer On a rack of multiple compressors, each compressor is controlled by: - Answer Which refrigerant line is most sensitive to improper sizing - Answer What is the most likely cause fo the following symptoms? The compressor shuts of on the oil pressure switch. Teh oil sight glass si 1/2 ful. Suction pressure si 3pig (R-502). Oil pressure is 70 psig. - Answer A Michigan serviceman is called to a supermarket on a cold winter day because all the frozen food is melting. Alow temperature rack of five compressors control the frozen food and ice cream units. Power supply is OK, but al compressors are of. Al five low pressure controls are open. The liguid receiver shows full. The hot gas discharge line is cold because the condenser is on the roof. What si the likely cause of the trouble? - Answer A string of five frozen food cases are operated by one compressor. All five cases are iced up. What is the likely problem? - Answer At what evaporator temperature does an ice maker begin to make ice? - Answer What device is used ot check for parallel misalignment of a motor coupling? - Answer Defrosting a low temperature evaporator can be accomplished by: - Answer A system that uses an Automatic Expansion Vvael (AEV) is not cooling enough and running continuously. The gauges reveal low head pressure, but the suction pressure is acceptable. This could be caused by - Answer