Question 106Refrigeration/AC - QMED70% to pass
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?
AI Explanation
The correct answer is A) short cycle on low-pressure cutout.
With the evaporator coil accumulating excessive frost due to a failure of the defrost mechanism, the refrigerant flow through the evaporator will be restricted, causing the low-pressure side of the refrigeration system to drop below the low-pressure cutout setting. This will cause the compressor to short cycle on the low-pressure cutout, shutting the compressor off until the pressure rises back above the cutout setting.
The other options are incorrect because: B) fail to start is not the likely symptom, as the compressor will attempt to start but be cut off by the low-pressure cutout; C) short cycle on high-pressure cutout is unlikely since the high pressure will not be the issue; and D) run continuously is incorrect, as the low-pressure cutout will prevent the compressor from running continuously.
Related Questions
#104 If the discharge reed valves used in a refrigeration compressor are leaking badly, what statement is true? #105 Which of the conditions listed may be an indication of an excessive amount of refrigerant circulating through the system? #107 Concerning the operation of refrigeration systems, frosting or sweating of a liquid line is usually indicative of what condition? #108 If an abnormally large difference is maintained between the evaporator refrigerant temperature and the box air temperature within the refrigerated compartment, what will be the result? #109 If the refrigeration compressor crankcase is sweating or frosting and is operating with an unusual noise, what is most likely the cause?