• Title/Summary/Keyword: 소손

Search Result 160, Processing Time 0.022 seconds

A Study on the Causal Analysis of Electrical Fire by Using Fuse (퓨즈를 이용한 전기화재의 원인분석에 관한 연구)

  • Lee, Chun-Ha;Kim, Shi-Kuk;Ok, Kyung-Jae
    • Fire Science and Engineering
    • /
    • v.22 no.1
    • /
    • pp.24-28
    • /
    • 2008
  • This paper studied on the causal analysis of electrical fire by using fuse that it is used with safety device in electrical products. The experimental samples used are glass tube fuse(15 A, $5{\times}20mm$) and temperature fuse(10 A, $72^{\circ}C$). The experiment analyzed on the characteristics of damaged fuse by main causes(short circuit, overload, external flame) of electrical fire. The results showed, in case of glass tube fuse identified different characteristics in external form and element surface and element texture of damaged fuse by main causes of electrical fire. In case of temperature fuse identified different characteristics in external form and sliding contact surface and sliding contact texture of damaged fuse only by external flame.

Study on the Fire Investigation by Damaged Pattern Analysis of Incandescent Lamps (백열전구의 소손 패턴 분석을 통한 화재조사 연구)

  • Kim, Hyang-Kon;Kim, Dong-Woo;Moon, Hyun-Wook;Choi, Chung-Seog;Choi, Hyo-Sang
    • Fire Science and Engineering
    • /
    • v.22 no.5
    • /
    • pp.22-28
    • /
    • 2008
  • In this paper, we conducted experiments on damaged patterns of incandescent lamps by external stress, such as external flame or external impact. Glass bulbs were melted and filaments were evaporated by external flame when the bulbs were lit, and finally molten marks were recognized at the filaments. Also, there were some differences in absorption patterns of evaporated filament elements according to set-up directions, and evaporated filament elements were absorbed in lead-in wires, support, inside of glass. In case the bulbs were lit and they were damaged by external impacts, filament burned out. Filaments were not evaporated but melted. We expect that this results could be used to judge whether electric current flew through incandescent lamps or not in fire site.

Assessment of the Combustion Diffusion Pattern and Fire Risk of a Water Purifier Damaged by a General Fire (일반화염에 의해 소손된 정수기의 연소 확산 패턴 및 화재위험성 평가)

  • Choi, Chung-Seog
    • Fire Science and Engineering
    • /
    • v.26 no.3
    • /
    • pp.35-39
    • /
    • 2012
  • This paper analyzes the combustion diffusion pattern when a water purifier is artificially ignited outside and inside in order to provide data to examine the cause of fire of a water purifier damaged by fire. The analysis result of the combustion diffusion pattern of a water purifier shows that the combustion diffused at a higher speed when it was ignited inside the purifier than when ignited outside. It took approximately 360 seconds for the water purifier to be half-burned when ignited on the outside, and approximately 180 seconds when ignited from inside. That is, it is thought that the internal combustion speed is higher because the internal ignition causes the generated heat to be accumulated and radiated instantly. It was observed that the water purifier damaged by fire caused by external ignition showed a uniform carbonization pattern and the carbide burned down at the bottom were gradually deposited. The water purifier damaged by internal ignition showed a relatively clear boundary of carbonized surface, which formed a V-pattern. The difference in the combustion patterns presents an objective base from which to determine where the fire started. By the time the purifier was half-burned by fire, the built-in fuse had not melted and the power supply protection device did not operate. In addition, as was found in the case of the fuse damaged by a general fire, carbonization occurred at the metal holder, and it is thought that this fact may be used as a basis from which to determine the cause of a fire.

Study of the Method to Examine the Cause of Damage to a Flat-Type Vinyl Cord (VFF) According to the Type of Energy Source (에너지원의 종류에 따른 비닐평형코드(VFF)의 소손원인 판정기법에 관한 연구)

  • Choi, Chung-Seog
    • Fire Science and Engineering
    • /
    • v.25 no.6
    • /
    • pp.83-88
    • /
    • 2011
  • This study presented the structure and characteristics of vinyl cords used for wiring electric equipment and appliances and analyzed the photographs of damaged flat-type vinyl cords (VFF, $1.25mm^2$) and the metallic cross-sectional structure of melted conductors. Normal VFFs were made by twisting several strands together and the surface of the conductor was red brown. In addition, from the analysis of the metallic structure of the conductor, it was found that its grains had been elongated. The surface of a VFF damaged by normal flame showed no sheen with carbonized insulation material fused on the conductor surface. In addition, from the analysis of the cross-sectional structure of the melted area, it was found that voids of a certain shape were formed on it but that the cord's own elongation structure could not be checked. The cross-sectional analysis of the melted conductor damaged by the external flame applied to a VFF to which electric current was being applied showed no elongation structure for each cord, and revealed that irregular voids and a columnar structure had grown. The surface of the VFF damaged by overcurrent was uniformly carbonized and the cross-sectional structure analysis of the melted conductor revealed that the dendritic structure had grown. The analysis of the characteristics of the VFF melted by short-circuit showed that even though some part of the surface was contaminated, it showed little sheen and that the area rebounded by melting was round in shape. In addition, the cross-sectional structure analysis using a metallurgical microscope showed the boundary surface and columnar structure and revealed an amorphous structure like normal copper at areas other than the melted conductor.