This standard covers the following types and preferred ratings for enclosed low-voltage ac power circuit breakers: a) Stationary or drawout type of two-@ three-@ or four-pole construction with one or more rated maximum voltages of 1058 V@ 730 V@ 635 V (600 V for units incorporating fuses)@ 508 V@ or 254 V for application on systems having nominal voltages of 1000 V@ 690 V@ 600 V@ 480 V@ or 240 V respectively b) Unfused or fused type c) Manually operated or power operated@ with or without a trip system d) Fused drawout assemblies 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 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 current-limiting fuses@ whether integrally mounted or nonintegrally mounted. Purpose This standard a) Establishes minimal functional requirements b) Establishes preferred rating structure c) Provides preferred ratings