The necessity of arc management in a circuit breaker
arc
Why is an arc management necessary in a circuit breaker?
Best Answer
Arc formation is not necessary in a circuit breaker. It is an undesirable but depending on current carried, unavoidable aspect of circuit breakers.
Arcs are generated when the flow of current is interrupted. A circuit breaker should incorporate a way to contain and extinguish this arc, and keep the device cool while the arc exists.
Hence, a better question might be, "why is arc management necessary in a circuit breaker?"
Yes, magnetism can and does affect arcs. Some large switches have permanent magnets to reduce arcing. This technique is more popular on DC, where arcing is generally worse. The magnetic field bends the arc, increasing its length, which makes it go out faster.
This term is a hangover from the original standard which was for fluorescent lamps only where it was used to differentiate between the power in the lamp and the power drawn from the supply by the ballast.
DALI started off as an annex to IEC60929 "A.C. supplied electronic ballasts for tubular fluorescent lamps - Performance Requirements" Annex E.4 - Control by Digital Signals. It is now IEC62386.
Subsequently, the standard has added support for many lamp types which do not use arcs to generate light, including low voltage halogen, incandescent and LED, but the term has remained for historical reasons.
Within IEC standards, terms not given in the definitions section should be found in Electropedia.
Best Answer
Arc formation is not necessary in a circuit breaker. It is an undesirable but depending on current carried, unavoidable aspect of circuit breakers.
Arcs are generated when the flow of current is interrupted. A circuit breaker should incorporate a way to contain and extinguish this arc, and keep the device cool while the arc exists.
Hence, a better question might be, "why is arc management necessary in a circuit breaker?"