scope:

The scope of this standard includes the following enclosed low-voltage ac power circuit breakers:

Stationary or drawout type of two-, three-, or four-pole construction with one or more rated maximum voltages of 635 V (600 V for units incorporating fuses), 508 V, and 254 V for application on systems having nominal voltages of 600 V, 480 V, and 240 V

Unfused or fused type

Manually operated or power operated, with or without electromechanical or electronic trip devices

Fused drawouts consisting of current-limiting fuses in a drawout assembly intended to be connected in series with a low-voltage ac power circuit breaker to form a nonintegrally fused circuit breaker

NOTE-In this standard, the term circuit breaker shall mean enclosed low-voltage ac power circuit breaker, either fused or unfused. The term unfused circuit breaker shall mean a circuit breaker without either integrally or nonintegrally mounted fuses, and the term fused circuit breaker shall mean a circuit breaker incorporating currentlimiting fuses.¹

This document applies to both integrally and nonintegrally fused circuit breakers.

¹ Notes in text, tables, and figures of a standard are given for information only and do not contain requirements needed to implement this standard.