Information on the concepts of protection of ac transmission 1ines is presented in this guide. Applications of the concepts to accepted transmission line protection schemes are presented as well. Many important issues, such as coordination of settings, operating times, characteristics of relays, mut...

A procedure to be used to perform a failure analysis is recommended. The procedure is primarily focused on power transformers used on electric utility systems, although it may be used for an investigation into any ac transformer failure. This document provides a methodology by which the most probabl...

Metal-clad (MC) medium-voltage switchgear that contains drawout electrically operated circuit breakers is covered. MC switchgear is compartmentalized to isolate components such as instrumentation, main bus, and both incoming and outgoing connections with grounded metal barriers. Rated maximum voltag...

Small power transformers have become a significant element in distribution systems supplying large commercial customers like major resort hotels and site-specific industrial customers that desire the local utility to own, operate, and maintain the serving transformer. These transformers can range in...

Low-voltage metal-enclosed switchgearwhich contains either stationary or drawout, manually or electrically operated low-voltage ac or dc power circuit breakers in individual metal compartments, in three-pole, four-pole, two-pole, or single-pole constructionis covered. Rated maximum voltage levels ar...