• Title/Summary/Keyword: The Electrical Fires

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The Fire Hazard of Screwed Electric Contacts Due to Mechanical Vibration at Low Voltage Equipment

  • Choi, Chung-Seog;Kim, Young-Seok;Kim, Hyang-Kon
    • International Journal of Safety
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    • v.4 no.2
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    • pp.18-23
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    • 2005
  • There are many electrical connections in the electric apparatus and most fires due to a fault contact result from a failure or misuse of electric apparatus and installation. The fault contact happens between electrical connections by the loose and the mechanical vibration. In this paper, we have investigated thermal and electrical properties of screwed electric contacts due to the mechanical vibration. The exciter was connected to a signal generator and power amplifier that provided the vibration frequency and amplitude. The vibration, temperature and voltage data were sent to a data acquisition system (DAQ). In the case that fault contact took place, the arc happened between the screwed electric contact and electric wire, heat due to the arc was transmitted to the adjacent insulators, for which the oxide could be generated more. In addition, a spark was generated and the insulator began to melt. Thus, the possibility of electrical fire became the highest in this case. Finally, when the fault contact takes place due to vibration, the hazard of an electric accident is very high.

The Effectiveness Analysis of the Resistive Leakage Current Monitoring by Analyzing the Phase of the Body Current (인체 통전전류 위상 분석을 통한 저항성 누설전류 감시의 유효성 분석)

  • Kim, Jae-Hyun;Lim, Young-Bea;Lee, Sang-Ick;Kim, Dong-Woo
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.27 no.9
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    • pp.90-99
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    • 2013
  • To analyze the effectiveness of the resistive leakage current monitoring as a technology preventing electrical accidents, in this paper, we have estimated the phase of the body impedance by using the body impedance model and the body impedance data from IEC. We also have analyzed the phase of the electric body current in the case of 60Hz/220V. From these results, we concluded that deliberate researches about the phase of the electrical body current and related regulations must be carried out before the resistive leakage current monitoring unit is used to protect electric shock. And we concluded that the resistive leakage current monitoring unit can be utilized to prevent electrical fires caused by electric leakage current without unwanted circuit break due to capacitive leakage current flowing from line filter capacitors to the earth.

Characteristics on Arc Waveform and RMS of Current by Conductive Powder (도전성 분말에 의한 아크전류의 파형 및 실효값 특성)

  • Kim, Doo Hyun;Kang, Yang Hyun
    • Journal of the Korean Society of Safety
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    • v.28 no.3
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    • pp.63-68
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    • 2013
  • This paper is aimed to make an analysis on characteristics of the parallel arc waveform and RMS of current at the electrical tracking state by conductive powder. In order to achieve the goal in this paper, field state investigation at metal processing companies in Chung-Nam province area was conducted. With the field state investigation, conductive powder were collected from metal processing companies. By experiment on electrical connector(breaker, connector) over which the conductive powder were scattered, arc waveform and RMS of current were measured. The measured waveform and RMS(root-mean-square) of current were analyzed to describe characteristics and patterns of electrical arc by the conductive powder. It was proved that conductive powder on electrical connector can flow electrical current enough to make electrical fire with high thermal energy. Also the change of sine waveform and RMS of current can be used to find out relationship between electrical fire and fault signal by conductive powder. The results obtained in this paper will be very helpful for the prevention of electrical fires occurred at the metal processing companies.

Study on the Motion Control of CCTV by Miroprocessor (마이크로프로세스를 사용한 CCTV의 동작제어에 관한 연구)

  • Cho, Soo-Hyun;Kim, Jee-Hyun;You, Jeong-Bong
    • Proceedings of the KIEE Conference
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    • 2008.10b
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    • pp.445-447
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    • 2008
  • The CCTV systems is the most extensively used for a burglar proof, a crime prevention and a Prevention forest fires etc. The CCTV systems which is used in present is a PAN/TILT form. We want to control of CCTV systems motion by Up/Down, Left/Right, Zoom In/Out, Focus, TELE. We design a 8051 microcontroller board and a Key Controller and a Relay Controller. We conformed its feasibility through the simulation.

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Analysis of Deterioration Characteristics of Polyvinyl Chloride Insulation Wires for Electrical Apparatus by Series Arcing (전기기기용 비닐절연전선에서의 직렬 아크에 의한 열화 특성 분석)

  • Kim, Hyang-Kon;Gil, Hyung-Jun;Kim, Dong-Ook;Kim, Dong-Woo;Choi, Chung-Seog
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2006.06a
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    • pp.234-235
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    • 2006
  • In this study, we experimented deterioration characteristics of PVC insulation wires for electrical apparatus by series arcing and analyzed the heat generation at the contacts of wires, glowing/growing process of copper oxide, waveforms of contact voltage, current, power dissipation, and so on. We found out that how glowing contacts and surface arcing can decompose PVC insulation and that subsequent series arc can lead to ignition. We expect that these results are useful for improving fire protection technology by providing a better understanding of how electrical fires can initiate.

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Characteristics of Pre-Post Contacts of DC Consent-Plug (직류용 콘센트-플러그의 초기-후기접점 특성)

  • Na, Jaeho;Wang, Yongpeel;Kim, Hyosung
    • The Transactions of the Korean Institute of Power Electronics
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    • v.21 no.4
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    • pp.290-295
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    • 2016
  • Socket-outlets and plugs are essential devices that supply electric power into user appliances. During plug-out operation of an engaged plug from the socket-outlet, the consistent arc between the plug and the socket-outlet could develop into heavy fires in DC systems but only a small spark in AC systems. This paper proposes a pre-/post-electrode method to prevent plugs and socket-outlets from melting by sustaining arc energy. To implement the proposed pre-/post-electrodes, an experimental plug is manufactured with two electrodes, in which a post resistance Rs is connected in between. This paper investigates the function of the post resistance Rs, in which the best value of the post resistance Rs is obtained through simulation and experiment.

Electrical Flashover Characteristic Test by Gas Flames(I) (화염에 의한 전기적 섬락특성 실험(I))

  • Sohn, H.K.;Lee, H.K.;Han, H.J.;Park, I.P.;Han, S.W.;Kim, B.G.;Oh, H.H.;Choi, I.H.
    • Proceedings of the KIEE Conference
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    • 2008.07a
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    • pp.450-451
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    • 2008
  • Most of the transmission lines in Korea pass through a mountains. The forest fire occurred in around the transmission lines make an accident such as flashover and faults in the power transmission lines. In spite of that risk, there are no research on the flashover characteristics by fires in electric discharge engineering in our country. Therefore, by studying flame's electrical conductivity, the paper recommended measures that can minimize transmission line's flashover accidents in the future, which can be caused by forest fire in a region where transmission lines pass through.

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Recommended Practice on the Precautinary System and Installation to prevent electrical fire from reoccurring in underground tunnel (지하구조물내 전기재해 방지를 위한 설치지침 및 예방시스템 구축)

  • Kim, Se-Dong;Kim, Young-Jin;Kang, Jae-Mo
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2005.05a
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    • pp.337-341
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    • 2005
  • Most utiltity systems are subject to frequent changes, often due to increased loads and demand to up-grade quality of service provided. Urban renewal, expressway construction and suburban growth have also caused significant changes in urban utility distribution systems. Recently, it is required that a guideline for planning of a complete system, the reasonable design and construction methods for the efficient installation common utility tunnels must be estabilished. It prompts drastic measures to guard cities and their inhabitants against the horror of massive fires in the future. Preparedness holds the key to safety.

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Behavior Study of Overhead Conductor due to Forest Fire and Agents (소화약제 및 산불에 노출된 가공송전선의 거동 변화)

  • Jang, Young-Ho;Kim, Byung-Geol;Kim, Shang-Shu;Han, Se-Won;Kim, Jin-Han
    • Proceedings of the KIEE Conference
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    • 2008.07a
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    • pp.1207-1208
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    • 2008
  • Forest Fire can cause a serious damage to overhead conductors. Therefore, the detailed investigation for the changes of mechanical and electrical properties of damaged conductors should be carried out to understand the effect of forest fires on conductors. This is very much important to maintain transmission line safely. Especially, this paper describes the changes of mechanical and electrical properties of conductor due to forest fire and agents. The detailed will be given in the text.

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A study on the precautinary measures to prevent electrical fire from reoccurring in underground tunnel (공동구내 전기화재 미연 방지를 위한 예방시스템 구축 사례 고찰)

  • Kim, Se-Dong
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2004.05a
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    • pp.429-433
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    • 2004
  • Most utiltity systems are subject to frequent changes, often due to increased loads and demand to up-grade quality of service provided. Urban renewal, expressway construction and suburban growth have also caused significant changes in urban utility distribution systems. Recently, it is required that a guideline for planning of a complete system, the reasonable design and construction methods for the efficient installation common utility tunnels must be estabilished. It prompts drastic measures to guard cities and their inhabitants against the horror of massive fires in the future. Preparedness holds the key to safety.

  • PDF