What is the major drawback of a conventional circuit breaker ? Drawbacks
Conventional aircraft circuit breakers, like those used in residential applications, are designed for thermal or bolted faults. Bolted faults occur when two wires touch each other solidly creating a classic short circuit. In these type faults, the breaker works just fine. When the bi-metallic strips heat up to the specified temperature, the breaker trips.
The problem with conventional circuit breakers pertains to their inability to detect arcing faults. Arcing faults are caused by breaks in wire insulation where microscopic cracks, abrasions, or broken insulation occur. They can also exist when wire is improperly installed or maintained. Because these arcing faults occur so quickly and cause little thermal impact on the bi-metallic element of a conventional circuit breaker, the circuit breakers are not able to detect the problem and break the electrical flow. This can allow the arcing event to continue to occur unnoticed. Although arcing faults can occur very quickly, their potential for causing significant damage is extreme. The temperatures at the arcing point can reach as high as 6,000 degrees Centigrade – hotter than the surface of the sun. This creates definite potential for fire.