Which of the following installations is covered by the NEC?

The National Electrical Code (NEC) is a widely adopted standard in the United States that provides guidelines for electrical installations to ensure safety and proper functioning. The NEC covers a vast array of electrical systems and installations, including those found in varied environments.

Industrial substations are essential components of power distribution systems, and their installation must adhere to safety and performance standards set by the NEC. Similarly, recreational vehicles (RVs) are subject to specific electrical code requirements to ensure safe operation while being mobile and at various park facilities. Public and private premises also fall under the jurisdiction of the NEC, as maintaining safe electrical practices in homes and businesses is critical for safety and compliance.

Given that all these installations—industrial substations, recreational vehicles, and public and private premises—are specifically addressed within the NEC, the correct choice encompasses each area uniformly under its regulatory umbrella. Thus, the inclusion of all these types of installations in the NEC aligns with its purpose of ensuring safe electrical practices across diverse applications.