Question 112Refrigeration & AC - Assistant Engineer

The correct answer is C) Clean off oxidation from the surface of the suction line and sensing bulb with fine abrasive cloth or steel wool. This is the correct answer because proper installation of a thermostatic expansion valve requires ensuring good thermal contact between the sensing bulb and the suction line. Any oxidation or corrosion on the surfaces can insulate the bulb and prevent it from accurately sensing the refrigerant temperature, which is crucial for the valve to function correctly. The other options are incorrect because they do not address the need to ensure proper thermal contact. Attaching the bulb with plastic ties (A) or adding insulation (B) does not clean the surfaces. Removing excess capillary tube (D) may affect the sensitivity, but does not ensure good thermal contact.