Risk of Electric Arcs by Conductive Dust Accumulated on Circuit Breaker

Abstract

:In general, the causes of the electrical fire are overcurrent, short circuit, poor contact, etc. This study is aimed to recognize the risk of electric arc to prevent electrical fires due to the conductive dust accumulated on the circuit breaker. The experiment was carried out by the method that conductive metal dust collected from the field is being accumulated on the experimental electrodes with gap of 13 mm until the arc is generated. In case that arc was generated, the amount of conductive dust was measured and the thickness was calculated. This experiments was conducted by particle size. In order to distinguish particle size, mesh size(60~100, 100~150, 150~200, 200~250mesh) was classified using a sieve. As the results of experiment for each of the particle sizes, it was confirmed that there is differences in the generation of arc depending on the thickness of dust accumulated. Key Words : arc, conductive dust, electrical fire, particle size † Corresponding Author : Yang Hyun Kang, Tel:+82-42-525-3119. E-mail :kyh93412@hanmail.net Department of Safety Engineering, Chungbuk National University, 12 Gaeshin-dong, Heungduk-gu, Cheoungju Chungbuk, 361-763, Korea 서 론 2012년도 소방방재청의 전기적 요인으로 인한 발화 요인별 화재현황에 따르면 절연열화에 의한 단락23.42%, 과부하 11.4%, 접촉⋅불량에 의한 단락 9.0%, 트래킹에 의한 단락 6.9%, 압착에 의한 단락 6.4%, 누 전 4.6%, 반단선 1.4%, 층간단락1.06%, 미확인 단락 25.95%, 기타 9.2%를 차지하고 있다

Energetic and magnetic directional aggregation properties of KPA@Fe3O4 composite particles prepared via a microcrystalline co-precipitation route

“…As an important battlefield weapon in the information warfare, electrically conducting materials or dusts, such as carbon fibers, copper aerosols, can cause the short circuit or paralysis to the electromagnetic equipment [4][5][6][7][8]. However, they are typically appropriate in exposed electromagnetic targets but are difficult to interfere the equipment with excellent sealing or protection.…”