What are the three classes of circuit breakers?

The three classes of circuit breakers are appropriately categorized as thermal, magnetic, and thermal-magnetic.

Thermal circuit breakers utilize a bimetallic strip that bends when heated due to excessive current flow. This bending mechanism triggers the breaker to open the circuit, preventing damage due to overheating.

Magnetic circuit breakers operate based on the magnetic field generated by the current flow. When the current exceeds a preset limit, the magnetic force will rapidly move a mechanism that opens the circuit. This rapid response is crucial for protecting against short circuits.

Thermal-magnetic circuit breakers combine both thermal and magnetic features. They provide the benefits of both thermal protection against overloads and magnetic protection against short circuits, making them versatile and commonly used in various applications.

This classification helps in understanding how different types of circuit breakers function and their applications in safeguarding electrical systems.