IEEE 1458

Description / Abstract: This document provides a recommended practice for the selection, application, and determination of the remaining life in molded-case circuit breakers used in industrial applications.

Purpose

Molded-case circuit breakers are one of the most widely used circuit protection devices in low-voltage (less than 1000 V [ac], 1500 V [dc]) applications. In spite of their wide use in industry, the average person specifying, installing, operating, and maintaining these devices has less than a complete understanding of them. The purpose of this document is to provide people who purchase or maintain molded-case circuit breakers with a single document that includes the following information:

—How molded-case circuit breakers operate

—How to correctly size and select molded-case circuit breakers

—How to safely maintain molded-case circuit breakers

—How to determine when a molded-case circuit breaker must be replaced