Question 195Refrigeration & AC - 1st Asst/Chief

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 buildup on the surfaces can act as an insulator, preventing the sensing bulb from accurately detecting the suction line temperature. Cleaning the surfaces ensures optimal heat transfer and proper operation of the thermostatic expansion valve. The other options are incorrect because they do not address the critical step of cleaning the surfaces for proper thermal contact. Removing excess capillary tube (A), attaching the bulb with plastic ties (B), or adding insulation (D) do not directly impact the thermal transfer between the sensing bulb and suction line, which is the key installation requirement for the thermostatic expansion valve.