Branch-Circuit, Feeder and Service Calculations, Part XXV

摘要

Understanding how to perform load calculations inaccordance with the National Electrical Code (NEC) is essential for the professional electrician. Loads must be calculated before installing branch-circuits, feeders and services. Chapter 2 in the NEC contains 10 articles. Article 220 contains requirements for calculating branch-circuit, feeder and service loads. Results from calculations in Article 220 are used with requirements from other articles to find conductor sizes and ampere ratings for overcurrent protective devices. For example, results from calculations in Parts III, IV and V of Article 220 are used with the provision in 215.2(A)(1) to find the minimum feeder-circuit conductor size.