Kenneth Cybart, Senior Technical Sales Engineer, Littelfuse, Des Plaines, Ill.

Getting it straight: interruption rating vs. short-circuit current rating

Specifiers often use the terms short-circuit current rating (SCCR) and interrupting rating (IR) interchangeably. But a system’s or component’s SCCR may depend on the fuse or circuit breaker used in the circuit. Not understanding this difference between SCCR and IR may lead to under-protection, fire, and possibly death.