What characteristic must countertop receptacles have according to NEC guidelines for dwellings?

The correct answer identifies a critical aspect of countertop receptacles according to the National Electrical Code (NEC) guidelines. Specifically, countertop receptacles are allowed to be installed below the surface in certain situations, typically for the purpose of minimizing exposure to accidental damage or water splash. This means that, in some designs, receptacles can be installed where they are not directly accessible at surface level, implying flexibility in their placement to accommodate kitchen layouts and appliance requirements, while still adhering to safety protocols.

Although other characteristics like waterproofing and appropriate installation height above the counter are essential considerations in electrical installations, the specific guideline regarding receptacles being placed below the surface pertains to the installation flexibility permitted by the code when appropriate measures are taken to ensure safety and accessibility. Therefore, understanding that receptacles may be strategically located beneath the surface allows for design creativity in kitchens and emphasizes the importance of following safety guidelines while adhering to practical application needs.