GB/T 10963.3-2016

This part of GB 10963 specifies the technical requirements for single-pole and two-pole circuit breakers (hereinafter referred to as circuit breakers) operating in DC circuits. These requirements include terms and definitions, classification, circuit breaker characteristics, marking and other product information, standard operating conditions, structural operation requirements, and relevant test requirements and test methods necessary to ensure the repeatability of test results. Single-pole circuit breakers refer to those with a rated DC voltage not exceeding 250 V, and two-pole circuit breakers refer to those with a DC voltage not exceeding 500 V and a rated current not exceeding 125 A. These circuit breakers are designed for use by untrained personnel and do not require maintenance. This part of the standard is intended for use in environments with a pollution level of 2. This part of the standard provides for the circuit breakers to have an isolation function. This part of the standard is also applicable to DC power systems with suspended power supply (non-grounded) that meet specific short-circuit test requirements. This part of the standard is also applicable to circuit breakers with several rated currents, provided that the devices that switch from one rated value to another during normal operation are inaccessible and cannot be switched to another rated value without tools. For circuit breakers with a protection level higher than IP20 in GB 4208, and those commonly used in harsh environmental conditions (such as excessive moisture, heat, cold, or dust accumulation) and in dangerous areas (such as areas prone to explosions), special structures may be required. This part of the standard provides for circuit breakers with features to prevent accidental disconnection, and they are not affected by inrush currents or electrical loads.