Which device protects electrical circuits in elevator systems from overload?

The circuit breaker serves as a crucial protective device in elevator systems by interrupting the flow of electricity when it detects an overload or a short circuit. This automatic disconnection of power prevents excessive current from damaging the electrical components of the system, ensuring that the elevator operates safely and reliably. In the event of an overload, the circuit breaker will "trip," cutting off electrical supply and preventing potential hazards such as overheating or fire.

While other devices like fuses also provide protection against overloads, circuit breakers have the advantage of being reusable after the fault is cleared, which makes them more convenient in maintaining system integrity. Transformers, on the other hand, are used to change voltage levels and do not provide overload protection. Relays are primarily used for control and automation purposes within the system and do not directly protect against overloads.