What must raceways on exterior surfaces of buildings be arranged to do?

Raceways on the exterior surfaces of buildings must be arranged to drain and be suitable for use in wet locations primarily to ensure safety and longevity of the electrical system. When raceways are installed in outdoor environments, they are exposed to various weather conditions, including rain and snow. If raceways are not designed to drain properly, water can accumulate inside them, leading to corrosion, electrical shorts, and potential failure of the electrical components housed within.

Additionally, being suitable for use in wet locations means that the materials used for these raceways must be resistant to moisture and capable of protecting the enclosed conductors from water ingress. This is crucial for electrical safety, as water and electricity pose significant hazards if they come into contact. Thus, ensuring proper drainage and wet location suitability is essential for maintaining the integrity and safety of the electrical installation.