Energized parts of service equipment that are not enclosed shall be installed on a device such as a switchboard, panelboard, or control board, or any of these.

• A. Any of these
• B. Panelboard
• C. Switchboard
• D. Control board

Answer: (A)

Energized parts that aren’t enclosed must be mounted on a device designed to contain them. Switchboards, panelboards, and control boards are all such devices, and the code explicitly allows any of these to be used. That’s why the best answer is that any of these devices satisfies the requirement—the rule isn’t limited to just one specific device. Using any of these ensures the energized parts are housed in a suitable enclosure that provides proper protection and safe access.