When will the ampacity of the maximum load served be determined for feeders?

The ampacity of the maximum load served by feeders is determined after adjustment or correction factors are applied because these factors account for various conditions that could affect the load-carrying capacity of the conductors. The National Electrical Code (NEC) outlines that certain conditions—such as temperature, number of conductors bundled together, and installation environment—can influence how much current a wire can safely carry, known as its ampacity.

By applying the necessary correction factors, the calculated ampacity reflects a more accurate representation of what the conductors can handle under specific conditions. This ensures that the electrical system operates safely and effectively, minimizing the risk of overload and potential hazards.

Determining ampacity before applying these factors would not give a true representation of the conductors' capabilities in real-world conditions. Immediate determination upon installation or during final inspection does not account for the necessary adjustments based on installation factors that could affect performance. Hence, applying correction factors first is essential to ensure a reliable evaluation of the feeder's ampacity.