Selective Coordination Using Circuit Breakers: How to maximize the safety and reliability of your electrical system design

摘要

Selective coordination generally describes the design of an electrical system in which the upstream protective device (fuse or circuit breaker) nearest to the system fault clears the fault without affecting the protective devices that are upstream from it. Figure 1 illustrates this concept, where a fault is seen on a feeder circuit breaker in a panel. In this example, the fault on the feeder serving panel (M) is protected by circuit breaker (L). With proper action, this will not trip protective devices (G), (E), or (A) upstream - and the fault is contained so that buses (B) and (H) are unaffected, as are the panels marked (N).