Recommended Practice for Calculating AC Short-Circuit Currents in Industrial and Commercial Power Systems

This recommended practice provides short-circuit current information including calculated short-circuit current duties for the application in industrial plants and commercial buildings, at all power system voltages, of power system equipment that senses, carries, or interrupts short-circuit currents. Equipment coverage includes, but should not be limited to, protective device sensors such as series trips and relays, passive equipment that may carry short circuit current such as bus, cable, reactors, and transformers as well as interrupters such as circuit breakers and fuses.