Which code book serves as a standard for electrical installations?

The National Electrical Code (NEC) is the authoritative standard for electrical installations in the United States. It provides guidelines and requirements for the safe installation of electrical wiring and equipment, aiming to protect people and property from electrical hazards. The NEC is updated periodically to reflect changes in technology, safe installation practices, and the changing needs of society, ensuring that electrical installations meet current safety standards.

Choosing the NEC as the correct answer reflects an understanding of its primary role in establishing safety standards specifically for electrical installations. Other organizations, such as the National Fire Protection Association, Institute of Electrical and Electronics Engineers, and Underwriters Laboratories, have important functions within the electrical and safety industries, but they do not serve as the main regulatory code for electrical installations like the NEC does.