What is the classification of the interior of underground raceways according to the NEC?

The classification of the interior of underground raceways is identified as a wet location according to the National Electrical Code (NEC). This classification is due to the potential exposure to moisture and liquid water accumulation that can occur in underground environments. Since these raceways are installed below the ground, they are subject to groundwater, rain, and other sources of moisture that can infiltrate the raceway.

The NEC defines a wet location as an area that is subject to saturation with water or other liquids, which aligns well with the characteristics of underground raceways. This designation impacts various installation requirements, including the types of cables and conductors that can be used, ensuring they are suitable for such conditions to prevent damage and maintain safety.

Understanding this classification helps electrical professionals ensure that they use the appropriate materials and methods when installing wiring and electrical components in such environments, thus adhering to the safety standards laid out in the NEC.