scope:

The scope of this standard includes enclosed low-voltage ac power circuit breakers, as follows:

(1) Stationary or draw-out type of two- or three-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.

(2) Unfused or fused type

(3)Manually operated or power operated, with or without electromechanical or solid-state trip devices.

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 integral fuses, and the term fused circuit breaker shall mean a circuit breaker incorporating current limiting fuses as an integral part of the unit.