This standard covers enclosed low-voltage DC power circuit breakers of the stationary or drawout type of single- or two-pole construction with one or more rated maximum voltages of 300 V, 325 V, 800 V, 1000 V, 1600 V, or 3200 V for applications on dc systems having nominal voltages of 250 V, 275 V, 750 V, 850 V, 1500 V, or 3000 V, with general-purpose, high-speed, semi-high-speed and rectifier circuit breakers; manually or power-operated; and with or without electro-mechanical or solid-state trip devices. It deals with service conditions, ratings, functional components, temperature limitations and classification of insulating materials, insulation (dielectric) withstand voltage requirements, test procedures, and application.

This standard covers the following types of enclosed low-voltage dc power circuit breakers : (1) Stationary or draw-out type of 1- or 2- pole construction (2) Having one or more rated maximum voltages, of 3200, 1600, 1200, 800, 325, or 300 V, for application on systems having nominal voltages of 3000, 1500, 1050, 700,275, or 250 V (3) Manually operated or power operated (4) With or without overcurrent trip devices