Zone 0, 1, and 2 locations are defined under which article?

The correct choice is the one that refers to Article 505, as this article outlines the requirements and definitions for locations classified as Zone 0, Zone 1, and Zone 2. These zones are specifically related to areas where there is a risk of explosive atmospheres due to flammable gases or vapors. Article 505 deals with hazardous locations and provides guidelines for the installation of electrical equipment to minimize the risk of explosion in these specific areas.

Understanding these classifications is crucial for ensuring safety in environments where explosive atmospheres can occur. The definitions and requirements set forth in Article 505 help electrical professionals to select appropriate equipment, materials, and installation methods to mitigate risks associated with hazardous locations, thereby protecting both personnel and property.

Other articles mentioned, such as 501, focus more on Class I locations, which is a different classification system, while articles 510 and 513 pertain to specific requirements for other types of hazardous locations or equipment, but do not cover the definitions for Zone 0, 1, and 2. Thus, it is clear that Article 505 is the relevant and correct source for the definitions of these zones.