Lamp holders installed in damp locations shall be listed for use in what type of locations?

Lamp holders installed in damp locations must be listed for use in wet locations because they are subject to moisture that can be more intense than typical damp environments. Wet locations are defined in the National Electrical Code (NEC) as areas that are exposed to water or moisture significantly, including those where water may collect or splash. Therefore, using lamp holders rated for wet locations ensures that they are adequately protected against these conditions, which can otherwise lead to electrical failures or safety hazards.

By requiring that lamp holders in damp locations be rated for wet locations, the NEC emphasizes the necessity of using fixtures that can withstand higher levels of moisture. This practice ensures safe operation and longevity of the lighting fixtures, as products specifically designed for wet conditions typically include additional protective features like sealed gaskets or coatings that help prevent water ingress.

In contrast, lamp holders suitable for dry locations would not provide the necessary protection against moisture, while those rated strictly for indoor locations could be insufficient if they are exposed to moisture from outside sources. Thus, ensuring the proper rating aligns with the safety standards specified within the NEC.