What is the Arc Flash Boundary?

The Arc Flash Boundary is defined as the distance from the source of an arc flash where the incident energy levels reach 1.2 cal/cm², which is considered the threshold for the onset of a second-degree burn. This definition is critical for ensuring the safety of personnel working around electrical equipment because it helps establish specific safe distances. By understanding this boundary, workers can take the necessary precautions and wear appropriate personal protective equipment (PPE) when operating within this defined area.

The other options do not accurately capture the definition of the Arc Flash Boundary. For example, the notion of a location for storing electrical appliances does not relate to the concept of arc flash safety. Similarly, while protective gear is indeed necessary, stating that all personnel must wear it within that area does not define what the boundary itself is. Lastly, arc flashes can occur over various distances, and simply stating a limit of where they can "successfully" happen does not provide the clear, measurable standard that the Arc Flash Boundary represents. Thus, the correct answer emphasizes both the measurable distance and the safety aspect of preventing injuries related to arc flash incidents.