Electrical expert witness David J. Marne, P.E., is the author of McGraw-Hill’s National Electrical Safety Code® (NESC®) Handbook. Here he explains the difference between the NESC® and the NEC®:
The National Electrical Safety Code® (NESC®) governs the construction, operation, and maintenance of utility lines, substations, and generating plants. It covers both electric power and communication lines from the generating plant to the customer’s meter. The NESC® used primarily by utility employees.
The National Electrical Code® (NEC®) governs the customer’s installation after the meter: homes, factories, industrial facilities, etc. The NEC® is used primarily by homeowners, electrical contractors, and electrical designers.