Which two devices are most commonly used for overcurrent protection?

Overcurrent protection is crucial in electrical systems to prevent damage caused by excessive current flow, which can lead to overheating and potential hazards like fires. The two devices most commonly employed for this purpose are circuit breakers and fuses.

Circuit breakers are designed to automatically disconnect power when the current exceeds a predetermined level, allowing for easy reset after the issue is resolved. They can offer both overload and short circuit protection and are reusable, making them a practical choice for many applications.

Fuses, on the other hand, contain a metal wire or filament that melts when the current rises above a safe threshold. This physically breaks the circuit, stopping the flow of electricity. Fuses are inexpensive and provide straightforward protection, although they must be replaced once they blow.

Both devices work effectively to safeguard electrical systems from overcurrent conditions, which is why they are the preferred solutions in the majority of electrical installations. Other options listed, such as capacitors, relays, switches, and transformers, do not serve the primary function of overcurrent protection, making them unsuitable choices in this context.