What are the illumination provisions for luminaires used in stairways?

The illumination provisions for luminaires used in stairways focus on safety and visibility. The requirement that the illumination must be continuous and adequate to prevent falls is crucial because stairways are high-traffic areas where the risk of accidents is elevated. Insufficient lighting can lead to trips or falls, making it essential that luminaires provide a consistent and sufficient level of illumination throughout the entire staircase.

Continuous illumination ensures that users can clearly see each step and any potential obstacles, thereby enhancing safety. This provision aligns with the overarching goal of the NEC to promote safety in electrical installations, especially in areas where accidents are more likely to occur due to the nature of the environment.

In contrast, adjustable illumination levels, minimal illumination, or the notion that only one luminaire is adequate do not meet the safety requirements established by the NEC. Adjustable illumination could lead to inconsistent lighting levels, which may compromise safety. Minimal illumination fails to provide the necessary visibility needed to navigate stairways safely, while relying on a single luminaire may not provide even coverage or light distribution, potentially leaving dark areas that could increase the risk of accidents.