Which code book is the primary reference for load calculations in the United States?

The National Electrical Code (NEC) is the primary reference for load calculations in the United States because it establishes the standards for electrical installations, including provisions for load requirements and calculations. The NEC outlines the necessary processes and guidelines for determining how much electrical load can be safely handled by different types of electrical systems and circuits.

Load calculations are crucial for ensuring that electrical systems are designed to operate safely and efficiently without overloading components, which could lead to failures or hazards. The NEC provides detailed methodologies for performing these calculations, ensuring consistency and safety across various applications in the electrical field.

Other organizations, such as the NFPA, IEEE, and IEC, provide valuable resources and standards in their respective fields; however, they do not serve as the primary reference for load calculations specifically within the United States. The NFPA is known for fire safety standards, while the IEEE focuses more on technical standards related to electrical engineering and the IEC is an international organization that develops global electrical standards.