Question 19Refrigeration & AC - Assistant Engineer

The correct answer is A) frosting at the evaporator inlet. An obstructed expansion valve can cause incomplete cooling of the evaporator, leading to frosting at the evaporator inlet. This is because the expansion valve controls the flow of refrigerant into the evaporator, and an obstruction can prevent the proper amount of refrigerant from entering, resulting in an incompletely cooled evaporator. The other options are incorrect because: B) a higher than normal discharge pressure is associated with a restricted condenser, not an obstructed expansion valve; C) a decrease in the amount of frosting across the drier is not a symptom of an obstructed expansion valve; and D) frosting at the suction side of the compressor is not a typical symptom of an obstructed expansion valve.