Main Classifications of Circuit Breakers

Circuit breakers can be classified in numerous ways, typically based on their arc-extinguishing medium, structural form, and intended application. Different types are suited to specific power systems and operating environments.

Based on the arc-extinguishing medium, common types include oil circuit breakers, air circuit breakers, sulfur hexafluoride (SF₆) circuit breakers, and vacuum circuit breakers. Among these, vacuum circuit breakers are widely utilized in medium-voltage systems, characterized by their compact size, long service life, and minimal maintenance requirements; SF₆ circuit breakers, conversely, are predominantly employed in high-voltage and ultra-high-voltage systems, offering superior insulation and arc-extinguishing capabilities.

Classified by structural form, circuit breakers can be categorized into types such as air circuit breakers (ACBs) and molded-case circuit breakers (MCCBs). ACBs are typically used as main switches in power distribution cabinets, featuring high capacity and comprehensive protection functions; MCCBs, on the other hand, are widely used in low-voltage distribution systems, distinguished by their compact dimensions and ease of installation.

Categorized by intended application, circuit breakers can be further classified into types such as distribution protection circuit breakers, motor protection circuit breakers, and residual current circuit breakers. Circuit breakers designed for different applications prioritize specific protection characteristics; for instance, motor protection types place greater emphasis on the ability to withstand high inrush currents during motor startup, while residual current protection types focus primarily on preventing electric shock hazards to personnel.