This standard covers the test procedures for enclosed low-voltage ac power circuit breakers as follows: a) Stationary or drawout circuit breakers of two-or three- or four-pole construction@ with one or more rated maximum voltages of 635 V (600 for units incorporating fuses)@ 508 V@ and 254 V for application on systems having nominal voltages of 600@ 480@ and 240 V. b) Unfused or fused type circuit breakers c) Manually operated or power-operated circuit breakers with or without electromechanical or solid-state trip devices. d) 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 non-integrally 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 non-integrally mounted fuses@ and the term fused circuit breaker shall mean a circuit breaker incorporating either integrally or non-integrally mounted current limiting fuses. This document applies to both integrally and nonintegrally fused circuit breakers.