Commercial Refrigeration Certification Questions & Answers 100% Correct!

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: A. operate at high efficiency. B. ensure that frost does not accumulate. C. sub-cool the compressor. D. ensure proper oil return. - ANSWERA. operate at high efficiency. The difference between the temperature of the refrigerant boiling in the evaporator and the temperature at the evaporator outlet is known as: A. evaporator superheat. B. latent heat. C. evaporator sub-cooling. D. sublimation. - ANSWERA. evaporator superheat. An expansion device that is stuck open will cause: A. low suction pressure B. a starved evaporator. C. excessive superheat D. a flooded evaporator - ANSWERD. a flooded evaporator When measuring evaporator superheat on a commercial system that has a long suction line, the pressure reading should be taken at the: A. compressor inlet. B. evaporator outlet. C. condenser outlet. D. receiver Inlet. - ANSWERA. compressor inlet. (Suction Line) Superheat measurements are best taken: A. during a hot pull down. B. at 8°F to 12°F. C. during defrost. D. with the system operating at design conditions. - ANSWERD. with the system operating at design conditions. A technician 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: A. a dirty coil. B. a refrigerant overcharge C. uneven air distribution. D. a blocked distributor. - ANSWERD. a blocked distributor. A TEV with an external equalizer is used on: A. evaporators with a high pressure drop.