• 한국안전학회지
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• 제27권3호
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• pp.36-41
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• 2012

Electrical Connections often cause fires due to poor contact. Occurrence rate of these fires tends to increase annually. The reason why poor contacts occur is often because it is the low mechanical pressure at the contact points. A typical connection method using mechanical pressure is a screw terminal type. This study reviewed these poor contact cases in the screw terminals. In order to get reproduction of such cases, two types of experiments were conducted. the first one was conducted under the normal contact condition, and the other one was conducted under the poor contact condition that screw terminal of breaker was loosen and did not meet the requirements of toque value. In both types of experiments, compulsory vibration was adopted as a variable to aggravate poor contacts. Each of various current values(4.5A, 9.0A, 13.5A) is input. In these experiments, relationships of a contact, electrical signal such as current and electric pulse by ZCT and thermal characteristics according to vibration effect are analyzed. The suggested data and results in this study provide the useful resources helping to investigate fires due to poor contact, and they develop the detector for poor contact and finally reduce the electrical fire occurrence rate.

• 한국화재소방학회논문지
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• 제33권1호
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• pp.15-22
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• 2019

최근 상가에서 사용되는 온장고에서 저장된 기호음료들의 유출로 인한 절연파괴로 화재가 발생한 사례가 자주 보고되고 있다. 하지만 기호음료의 전기적 특성과 음료 유출로 인한 화재 발생 원인에 대한 연구는 미비한 상태이다. 이에 본 연구에서는 이에 대한 인과 관계를 밝히고자 기호음료 32종을 선별하여 전도도 및 총 용존 고형물질(TDS)의 농도를 측정하였다. 그리고 이를 바탕으로 음료를 선별하여 전극 간 절연파괴 시험과 회로에 소자와 음료를 같이 배치한 후 모의실험을 실시하였다. 그 결과 화재 발생 가능성은 전도도가 높은 음료는 물론 낮은 음료라도 발화 가능성이 있다는 사실을 실험적으로 확인하였다. 또한, 기호 음료의 유출로 회로상에서 불꽃 방전을 일으키는 여러 조건을 발견할 수 있었다.

• 한국전기전자재료학회논문지
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• 제31권6호
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• pp.412-416
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• 2018

Most series arcs lead to electrical fires that cannot be interrupted by circuit breakers, because the arc's current is outside the breaker's operating range. In this paper, experiments were conducted on the detection and identification of series arcs to prevent electrical fires. Plugs and outlets specified in KS C 8305 were deteriorated to replicate arc faults commonly found in fields. The characteristics of series arcs resulting from various types of loose connections were determined by analyzing the frequency spectra and phase distributions of detected arc pulses. The results showed that the simulated arc defects used in this study were more similar to actual arc phenomena than the existing arc generator specified in UL 1699. In addition, loose connections, such as wire-wire, terminal-wire, and outlet-plug, can be identified by phases of $0^{\circ}$, $180^{\circ}$ and $360^{\circ}$, respectively. These phases can be detected by a band pass filter with a frequency range of 5~10 MHz, which can be used as the trip signal for circuit breakers.

• 한국화재소방학회:학술대회논문집
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• 한국화재소방학회 2003년도 하계 심포지움
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• pp.45-50
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• 2003

• 한국안전학회지
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• 제29권5호
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• pp.47-53
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• 2014

Despite the automatic fire alarm system, according to the national fire data system of national emergency management agency, the fires account for 40,932 incidents, 2,184 injuries and about 430 billion won in property losses in 2013. Since the conventional automatic fire alarm system has several weaknesses related to electrical signal such as noise, surge, lighting, etc. Most fires are mainly caused by electrical faults, mechanical problem, chemical, carelessness and natural. The electrical faults such as line to ground fault, line to line fault, electrical leakage and arc are one of the major problems in fire. This paper describes the development of a novel real-time fire monitoring system algorithm including fault detection function which puts the existing optic smoke and heat detectors for fire detection with current and voltage sensors in order to utility fault monitoring using high accuracy DAQ measurement system with LabVIEW program. The fire detection and electrical fault monitoring with a proposed a new detection algorithm are implemented under several test. The fire detection and monitoring system operates according to the proposed algorithm well.

• 한국안전학회지
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• 제31권2호
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• pp.1-9
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• 2016

The standard procedure of fire modeling was reviewed to minimize the user dependence, based on the NUREG-1934 and 1824 reports. The hazard analysis of lubricating oil fires in the air compressor room of domestic nuclear power plant (NPP) was also performed using a representative fire model, FDS (Fire Dynamics Simulator). The area ($A_f$) and location of fire source were considered as major parameters for the realistic fire scenarios. As a result, the maximum probability to exceed the thermal damage criteria of IEEE-383 unqualified electrical cables was predicted as approximately 70% with $A_f=1m^2$. It was also found that for qualified electrical cables, the maximum probabilities of exceeding the criteria were 2% and 90% with $A_f=2$ and $4m^2$, respectively. It was concluded that all electrical cables should be replaced with IEEE-383 qualified cables and the dike to restrict as $A_f{\leq}2m^2$ should be installed at the same time, in order to assure the thermal stability of electrical cables for lubricating oil fires in the air compressor room of domestic NPP.

• 한국안전학회지
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• 제34권5호
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• pp.55-62
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• 2019

In this paper, we introduce a case of a fire accident during parking of a large truck that is repeatedly occurring. The shape and location of the combustion and electrical singularity commonly found in other vehicle fire accidents could limit the starter motor as the ignition section. In addition, it was possible to confirm the electrical melting singularity that could act as a cause of ignition between the start motor B terminal and the start motor enclosure. By combining the above investigations and investigations, it was possible to estimate the electric fire expressed from insulation breaking of the starter motor B terminal, and by using the renewable starter motor comparison product mounted on the fire vehicle, an experiment was performed to reproduce the ignition process from the starter motor under specific conditions. So. It is hoped that this will raise awareness about vehicle fires, which can lead to large fires or casualties, share the risks of using starter motors for regeneration, and help in the rapid and accurate investigation of similar vehicle fires in the future.

• 전자공학회논문지
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• 제50권9호
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• pp.189-193
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• 2013

이본 논문은 전력시스템에서 발생하는 전기화재를 예측하고 예방하기 위하여, 전력정보를 계측하고, 이 정보를 활용하여 전기화재를 예측하는 시스템을 제안하였다. 이를 위하여 과전류, 과부하와 과열에 대한 상관관계를 분석하였다. 이러한 상태들은 지락전류와 누설전류에 의하여 발생하고, 전기화재의 주요 원인이기 때문이다. 이 관계를 이용하여 퍼지규칙을 위한 소속도함수를 도출하였다. 또한 설계된 알고리즘에 수배전반의 실측된 전력정보를 활용하여 시뮬레이션 하였다.

• 한국건설안전학회 논문집
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• 제1권1호
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• pp.31-39
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• 2018

국내에서 발생하는 화재사고 중 약 20%가 전기설비에서 기인한 화재로 확인되고 있다. 복잡하고 대형화되어있는 건축물에서 전기화재는 재산 피해와 인명 피해가 증가하면서 대형화하는 양상으로 발생하고 있다. 여러 가지 전기화재의 원인 중 누전에 의한 발화가 약 71.5%를 차지하고 있고, 전기설비별 분류에서는 배선 및 배선기구에서 발생하는 화재가 약 38.3%를 차지하고 있다. 본 연구의 목적은 현재 사용되고 있는 옥내배선 형태를 개선하여 누전으로 인한 전기화재를 예방하는 방법을 제시하고, 배선기구에서 범용 되고 있는 콘센트와 플러그를 개선하여 배선기구에서 발생하는 화재를 예방하는 근원적 방안을 찾고자 한다. 본 연구를 통해서 제시되는 전기화재 예방대책은 전기화재의 근원적 원인을 제거하여 많은 인명과 재산을 보호하는 대책으로 활용될 수 있을 것으로 기대된다.

• Safety and Health at Work
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• 제11권4호
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• pp.405-417
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• 2020

Background: Electrical socket outlets are used continuously until a failure occurs because they have no indication of manufacturing date or exchange specifications. For this reason, 659 electrical fires related to electrical socket outlets broke out in the Republic of Korea at 2018 only, an increase year on year. To reduce electrical fires from electrical socket outlets, it is necessary to perform an accelerated test and analyze the thermal, insulation resistance, and material properties of electrical socket outlets by installation years. Methods: Thermal characteristics were investigated by measured the temperature increase of electrical socket outlets classified according to year with variation of the current level. Insulation resistance characteristics was measured according to temperature for an electrical socket outlets by their years of use. Finally, to investigate the thermal and insulation resistance characteristics in relation to outlet aging, this study analyzed electrical socket outlets' conductor surface and content, insulator weight, and thermal deformation temperature. Results: Analysis showed, regarding the thermal characteristics, that electrical socket outlet temperature rose when the current value increased. Moreover, the longer the time that had elapsed since an accelerated test and installation, the higher the electrical socket outlet temperature was. With respect to the insulation resistance properties, the accelerated test (30 years) showed that insulation resistance decreased from 110 ℃. In relation to the installation year (30 years), insulation resistance decreased from 70 ℃, which is as much as 40 ℃ lower than the result found by the accelerated test. Regarding the material properties, the longer the elapsed time since installation, the rougher the surface of conductor contact point was, and cracks increased. Conclusion: The 30-year-old electrical socket outlet exceeded the allowable temperature which is 65 ℃ of the electrical contacts at 10 A, and the insulation resistance began to decrease at 70 ℃. It is necessary to manage electrical socket outlets that have been installed for a long time.