Enclosed dc power circuit breakers of the stationary or drawout 32 type of one- or two-pole construction with one or more rated maximum voltages of 300 V, 325 V, 33 600 V, 800 V, 1000 V, 1200 V, 1600 V, or 3200 V for applications on dc systems having nominal 34 voltages of 250 V, 275 V, 500 V, 750 V, 850 V, 1000 V, 1500 V, or 3000 V, with general-purpose, 35 high-speed, semi-high-speed and rectifier circuit breakers; manually or power-operated; and with 36 or without electromechanical or electronic trip devices are covered in this standard. Service conditions, ratings, 37 functional components, temperature limitations and classification of insulating materials, dielectric 38 withstand voltage requirements, test procedures, and application are dealt with in this standard.