Which safety switch must be installed to meet NEC® requirements when there is a full-height wall between a panel and a motor?

To meet NEC® (National Electrical Code) requirements in situations where a full-height wall separates a panel from a motor, it is important to ensure that the circuit remains easily accessible and safe for operation. The key is that the safety switch should be located in a position that allows for quick disconnection of the motor's power source without needing to access the panel room.

In this context, the safety switch designated as Y would be the appropriate option because it typically provides a means of disconnecting power to the motor without being inside the room where the panel is located. By having the Y switch installed near the motor, it allows for safe operational practices, such as when maintenance is required, while adhering to NEC® standards regarding visibility and accessibility.

The other option(s) may not satisfy the requirements due to their placement or lack of accessibility, which is a crucial concern in electrical installations to ensure safety during maintenance or emergencies.