Under NEC Article 300.48, what is required when performing a load calculation?

The requirement under NEC Article 300.48 for performing a load calculation emphasizes the importance of obtaining accurate measurements of load demands. This ensures that the electrical system is designed and installed correctly to handle the anticipated loads, preventing issues such as circuit overloads, overheating, or potential fire hazards.

Accurate measurements provide a reliable basis for determining the size of conductors, protective devices, and other system components, ensuring that the installation meets safety standards and operates efficiently. This precision is critical, especially in settings where varying loads could impact performance and safety, such as commercial or industrial facilities.

While estimating load demands may be useful in preliminary planning or for smaller projects, it does not provide the level of accuracy needed for compliance with code requirements. Similarly, relying on average values or conducting only visual inspections would not satisfy the NEC's standards for load calculations, which must be based on precise data. Thus, the emphasis on accurate measurement is pivotal for safe and compliant electrical installations.