How does incident energy change as distance from the arc source increases?

As distance from the arc source increases, incident energy decreases due to the inverse square law, which describes how energy disperses in space. When an electrical arc occurs, the energy released propagates outward in all directions. As you move further away from the source of the arc, the same amount of energy is spread over a larger area, leading to a reduction in energy density, or incident energy, that is experienced at a given point.

This phenomenon is relevant in electrical safety, particularly when assessing risks and implementing safety measures for those working near potential arc flash hazards. Understanding how distance affects incident energy is key to ensuring proper protective measures, such as the appropriate selection of personal protective equipment (PPE) and the safe design of work zones around electrical equipment.