NESC

The NESC is the US National Electrical Safety Code governing the design and loading of overhead and underground lines.

The National Electrical Safety Code (NESC) is the standard governing the safe design, construction and maintenance of electric supply and communication lines in the United States. For distribution design it defines loading districts (Heavy, Medium and Light), clearance requirements and safety factors that pole loading analysis and make-ready must satisfy. Canadian work uses the equivalent CSA standards.