What is the difference between DC circuit breaker and AC circuit breaker

The main difference between DC circuit breakers and AC circuit breakers lies in their electrical characteristics and design requirements.

Electrical characteristics

1. Current direction: The current in a DC circuit is unidirectional, while the current direction in an AC circuit will constantly change. This difference leads to fundamental differences in design and application between the two. ‌

2. Arc extinguishing capability: AC circuits have zero crossings in each cycle, making it easy to extinguish the arc; However, DC circuits do not have zero crossing points and have poor arc extinguishing capabilities, so special arc extinguishing devices are needed to enhance their arc extinguishing capabilities.

Design requirements

1. Voltage level: The rated voltage of DC circuit breakers is usually low, generally below 1000V

2. Melting capacity: The melting capacity of DC circuit breakers is relatively large, usually reaching over kiloamperes; The melting capacity of AC circuit breakers is relatively small, usually below a few hundred amperes.