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The basics of device circuit breakers | Differences between the technologies
2.4 Which type of circuit breaker is recommended and when should it be used ?
Device circuit breakers are selected based on the nominal voltage , nominal current , and , if required , the starting current of an end device . In addition , the shutdown behavior of the device circuit breaker must correspond to the expected fault situations . Fault situations are divided into short circuit and overload . A thermal device circuit breaker provides pure overload protection . However , it is not equipped with a protective mechanism that can quickly and reliably protect the application from short circuits . This means that increased tripping times occur in the event of short circuits .
Thermomagnetic circuit breakers are also significantly better suited for safely protecting a load from short circuits . They offer a combination of medium-blow overload protection and fast-acting and reliable short-circuit protection .
Even very high starting currents are no problem for most thermomagnetic characteristic curves .
Electronic circuit breakers are significantly more accurate . Circuit breakers with an electronic characteristic curve are used to create fast-acting overload and short circuit protection . They are used upstream from particularly sensitive loads and protect not only against overly long , but also against overly high loading . Electronic circuit breakers are therefore not just especially well suited for protecting systems and machines , but also often provide comprehensive diagnostic options . Remote maintenance can be designed to be significantly more comprehensive .
Moreover , thanks to its extended remote signaling and control options , this type of circuit breaker can be used in some cases in hard-to-reach applications .
Recommended selection depending on shutdown behavior and fault situation
Tripping time in the case of overload
Tripping time in the event of a short circuit
Thermal circuit breakers
Thermomagnetic circuit breakers
Electronic circuit breakers
Shutdown behavior : Unsuited Adequate Ideal
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