DC molded case circuit breakers (MCCB) are core protection devices in DC systems, used for power distribution and protecting lines from overloads and short circuits. They operate based on the thermomagnetic effect, offering fast tripping and efficient arc extinguishing. They feature a compact design, support a variety of accessories, and interlocking features, ensuring safety and reliability. They are widely used in photovoltaics, electric vehicle charging, data centers, and rail transit.