Where should the bulb of the thermostatic expansion valve be attached during a routine inspection?

The bulb of the thermostatic expansion valve plays a crucial role in regulating the flow of refrigerant to ensure that it evaporates completely within the evaporator coil, maintaining efficiency and temperature control in a refrigeration system.

Attaching the bulb at the end of the coil is the correct choice because this placement allows the bulb to accurately sense the temperature of the refrigerant as it exits the evaporator. By detecting the temperature of the refrigerant vapor at this point, the valve can adjust the flow of refrigerant more effectively, preventing issues such as frost build-up or inefficient cooling.

In contrast, attaching the bulb at the base of the evaporator would not provide accurate readings of the refrigerant leaving the coil, which could lead to improper valve operation. Placement in the control panel would be irrelevant because it would not provide any insight into the refrigerant's state as it undergoes the evaporation process. Lastly, attaching the bulb at the induction line could lead to misleading temperature readings, as it doesn't account for the actual evaporation occurring within the coil.

Thus, ensuring the bulb is positioned at the end of the coil optimizes system performance by enabling the expansion valve to manage refrigerant flow based on precise temperature feedback.