Overcurrent circuit breaker (circuit breaker) - definition
Overcurrent circuit breaker (circuit breaker) - definition
Circuit Breakers is a mechanical protective switch designed to automatically interrupt the flow of electric current in a circuit when a certain current value is exceeded. Its function is to protect the electrical installation, consumers and users from the effects of overloads and short circuits that can lead to overheating of the Cables, damage to the equipment or fire. The overcurrent circuit breaker has a protective function comparable to a fuse, but has the ability to be repeatedly switched on after tripping, making it easier to operate and service.
The essential design elements of an overcurrent circuit breaker are the overload and short-circuit detection mechanisms. The overload action is realised by means of a thermal trip, usually in the form of a bimetal that bends when the temperature rises, triggering the disconnection mechanism. Short-circuit is detected by an electromagnetic trigger - a coil that generates a force upon a sudden increase in current, allowing the contacts to open immediately. In both cases, the opening of the current path interrupts the flow of energy to the protected section of the installation.
Circuit Breakers are classified according to the time-current characteristic, which defines the response time of the device depending on the level of current. Characteristics B, C and D are the most commonly used, differing in their sensitivity to current pulses and their suitability for different types of consumer. Modern circuit breakers can also integrate additional functions such as residual current protection, remote control capability or communication in building automation systems.
In installation practice, the overcurrent circuit breaker is mounted on a DIN rail in switchgear and is an essential component of the short-circuit and overload protection system. The selection of a suitable model requires consideration of the current rating, protection characteristics and short-circuit parameters of the network. The operation of the circuit breaker should comply with the applicable standards, including IEC 60898 or EN 60898.
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