What is the purpose of the trip unit in a circuit breaker?

The purpose of the trip unit in a circuit breaker is to sense overcurrent conditions and release the contacts when such conditions occur. This is crucial for protecting electrical circuits from damage. When the current flowing through the breaker exceeds a predetermined limit, which could indicate a short circuit or overload, the trip unit actuates a mechanism that opens the circuit, thus interrupting the flow of electricity. This automatic shutdown prevents overheating, potential fires, and damage to the electrical devices connected to the circuit.

Choosing to incorporate a trip unit in circuit breakers enhances safety and reliability in electrical systems, making it an essential feature for effective circuit protection.