• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.05c
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• pp.7-10
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• 2002

In this study, polyolefin compounds were developed and evaluated for replacing a jacket material of URD power cables. The characteristics of compounds were investigated by water vapor transmission (WVT) test and mechanical test. In WVT test, all polyolefin compounds showed the superior water resistance to conventional PVC. The molecular structure and density of polyolefin play an important role in WVT. Also, polyolefin compounds showed the suitable characteristics in mechanical test. Especially, polyolefin compounds having linear molecules showed the superior characteristics to LDPE ones. From this study, it can be considered that polyolefin compounds may be suitable to jacket material for URD power cables.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2004.05a
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• pp.497-501
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• 2004

The primary failure causes of underground distribution power cables are water penetration in insulation layer and stress enhancement at inner semi-conductive layer. Accordingly, it is needed to improve the materials and the structure of power cables for extending lifetime and preventing failure. We uses non-flaming PE materials instead of PVC as a covering material and encapsulating structure. We also use super smooth class material as a inner semi-conductive layer. The newly developed cables are improved in AC breakdown voltage after ageing tests.

• Proceedings of the KIEE Conference
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• 2008.09a
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• pp.58-60
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• 2008

발전소에서 만들어진 전력을 소비자까지 수송하는 송변전변 및 배전설비를 주 대상으로 하는 전력계통 설비의 운영에는 전력의 수송과 이를 위해 설치되는 각종 기자재로부터 인체 및 재산의 안전을 확보하기 위해 많은 종류의 절연재를 사용하고 있다. 지금까지 전력분야에서 사용되어 온 절연재는 자기재(porcelain)가 주종을 이루어 왔으나 재료기술의 발달과 함께 폴리머 절연재료들이 속속 개발되면서 자기재에 비해 가격 및 시공성 등에서 이점이 많은 폴리머 절연재가 자기재를 대체하고 있다. 그러나 폴리머 절연재료는 기들의 재질 및 사용 환경 등에 따라 일정 수명을 가지는 것으로 나타나 수명종기에 이르면 폐기물로 배출되게 된다. 전력산업 중 배전분야에서는 2007년 구매한 기자재를 기준으로 연간 13만연 톤의 전력폐기물이 발생될것으로 예측되었으며 이들은 PE, XLPE, FRP, PVC, EPDM, Silicone 등 유기성분이 약 40%, Cu, Al, 철 등 금속과 무기성분이 약 60% 인 것으로 조사되었다. 그러나 전선 및 케이블류를 제외한 기자재를 대상으로 한 분석에서는 유기성분의 함량이 90%에 이르며 이들은 석유화학공업의 원료로부터 만들어지는 특성상 높은 에너지를 함유하는 것으로 나타난 바, 이들을 적정하게 처리하는 방안의 확보는 폐기물의 처리 외에 폐기물로부터 에너지를 회수하여 자원화하는 것이 가능한 것으로 보여진다.

• 한국정보통신설비학회:학술대회논문집
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• 2005.08a
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• pp.229-237
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• 2005

통신용 지하 관로는 대부분 내경 100mm인 PVC 재질로 되어 있으며, 지하에 매설한 후 또는 관로를 사용하기 전에 관로 상태의 정상 유무를 확인할 목적으로 맨드릴(직경 90mm)을 이용한 선통 검사로 정상 관로와 불량 관로를 판단 하였다. 그러나 이러한 방법으로는 조사 대상 관로의 불량 원인을 밝힐 수 없을 뿐 아니라, 복수 개소의 불량 지점을 확인하는 것이 불가능하여 관로 보수나 사용을 위한 기본적인 관로 정보를 제공할 수 없었다. 이러한 문제를 해결하기 위해 디지털 관로 조사장비를 개발하였으며, 관로 내부를 따라 관로 카메라를 이동시키면서 관로 내부의 변형 상태를 실시간으로 확인하거나, 관로 벽에 조사된 레이저 빔 영상을 검출하여 관로 단면의 최소 직경을 측정할 수도 있다. 또한, 디지털 맨드릴은 1mm 간격으로 관로의 내경을 측정할 수 있는 게이지가 설치되어 있어, 실시간으로 관로 단면의 최소 직경을 측정할 수 있어 조사 관로의 전반적인 변형 정도를 모니터링 할 수 있다. 이러한 디지털 관로 조사장비를 이용하여 신설 관로의 시공품질을 측정하거나, 기존 관로의 상태를 객관적이고 정확하게 파악하여 관로 상태에 따른 케이블 포설 계획을 수립할 수 있으며, 불량 관로 보수를 위한 정확한 자료를 제공하여 유지관리의 효율성을 높일 수 있다.

• Journal of the Korean Society of Safety
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• v.33 no.5
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• pp.15-20
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• 2018

This paper describes the fusing time characteristics of Light PVC Sheathed Circular Cord(VCTF) and Tray Frame Retardant(TFR) cables according to increased temperature under over current condition. The experimental equation will be used to determine the validity and reliability of the test results. The over current flowed 3, 5 and 10 times higher than the amount of allowable current using DC power supply with DAQ(Data Acquisition) measurement system. An infrared radiation heater, which was controlled by a variable AC auto transformer, was used to increase the temperature from room temperature to 50, 100 and 150 degrees Celsius. First, two type of cables were analyzed those with different cross-sectional areas with in the same structure and those with different structures with in the same cross-sectional areas. Then, it was determined how fusing time had been influenced according to the cross-sectional areas and different structures, respectively. The cable resistance was increased by joule heating according to increasing temperature. Therefore, the allowable current of cable is decreased. Finally, the fusing time of the cable was decreased due to increased temperatures at current flow, which were 3 times the amount of allowable current. The instantaneous breakdown was observed when current flow was 5 and 10 times over the amount of allowable current. The fusing time is directly affected by the structure of cable insulation.

• Fire Science and Engineering
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• v.17 no.4
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• pp.36-41
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• 2003

This experimental study shows the combustion characteristics for each coating thickness of water and oil paint which are used as fire retardant paints that prevent fire propagation through cables in underground culverts and trays. To evaluate combustion characteristics, smoke density(ASTM E 662) and Limited Oxygen Index(ASTM D 2863) experiment method was used. As the results of this study, the combustion characteristics of fire retardant paints produced the following : (a) The molt suitable coating thickness of fire retardant paint was 1.5∼2.0 mm in water paint and 0.2 mm in oil paint. (b) Flaming method in experiments of smoke density were found to be higher than Non-flaming method. (c) Water paint has the fire retardant effect and characteristics better than oil paint in measurement results of smoke density and oxygen index. (d) The oxygen index of water and oil fire retardant was able to know that it was satisfied a standard (30 or above).

• Journal of the Korean Society of Safety
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• v.28 no.3
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• pp.39-43
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• 2013

The present study has been conducted to investigate the fire combustion properties and fire behavior of an IEEE-383 qualified flame retardant cable. The reference reaction rate and reference temperature which are commonly used in pyrolysis model of fire propagation process was obtained by the thermo-gravimetric analysis of the cable component materials. The mass fraction of FR-PVC sheath abruptly decreased near temperature range of $250{\sim}260^{\circ}C$ and its maximum reaction rate was about $2.58{\times}10^{-3}$[1/s]. For the XLPE insulation of the cable, the temperature causing maximum mass fraction change was ranged about $380{\sim}390^{\circ}C$ and it has reached to the maximum reaction rate of $5.10{\times}10^{-3}$[1/s]. The flame retardant cable was burned by a pilot flame meker buner and the burning behavior of the cable was observed during the fire test. Heat release rate of the flame retardant cable was measured by a laboratory scale oxygen consumption calorimeter and the mass loss rate of the cable was calculated by the measured cable mass during the burning test. The representative value of the effective heat of combustion was evaluated by the total released energy integrated by the measured heat release rate and burned mass. This study can contribute to study the electric cable fire and provide the pyrolysis properties for the computational modeling.

• Journal of the Society of Disaster Information
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• v.10 no.4
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• pp.583-597
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• 2014

Fire caused by heater has various causes as many as the types of heater. also, lots of damage of human life and property loss are caused, since annually continuous fire accident by heater in traditional market is frequently occurring. There are not many cases of fire due to heater in most of residential facilities such as general house, apartments, etc., because they are supplied with heating boiler, however the restaurant, store and office of the market, sports center, factory, workplace, etc. still use heater, e.g. oilstove, electric heater, etc., so that they are exposed to fire hazard. Also, when investigating the number of fire due to heater, it was analyzed to occur in order of home boiler, charcoal stove, oilstove, gas heater/stove, electric stove/heater, the number of fire per human life damage was analyzed in order of gas heater/stove, oil heater/stove, electric heater/stove, briquette/coal heater. Also, gas and oil related heater were analyzed to have low frequency, however, with high fire intensity. Therefore, this research aimed at considering more scientific fire inspection and identification approach by reenacting and reviewing fire outbreak possibility caused by combustibles' contact and conductivity under the normal condition and abnormal condition in respect of ignition hazard, i.e. minimum ignition temperature, carbonization degree and heat flux along with it, due to oilstove and electric stove, which are still frequently used in public use facility, traditional market, and, of which actual fire occurrence is the most frequent. As the result of reenact test, ignition hazard appeared very small, as long as enough heat storage condition is not made in both test objects(oilstove/electric stove), however carbonization condition was analyzed to be proceeded per each part respectively. Eventually, transition to fire is the ignition due to heat storage, so that it was analyzed to ignite when minimum heat storage temperature condition of fire place is over $500^{\circ}C$. Particularly, in case of quartz pipe, the heating element of electric stove, it is rapidly heated over the temperature of $600^{\circ}C$ within the shortest time(10sec), so that the heat flux of this appears 6.26kW/m2, which was analyzed to result in damage of thermal PVC cable and second-degree burn in human body. Also, the researcher recognized that the temperature change along with Geometric View Factor and Fire Load, which display decrease of heat, are also important variables to be considered, along with distance change besides temperature condition. Therefore, the researcher considers that a manual of careful fire inspection and identification on this is necessary, also, expects that scientific and rational efforts of this research can contribute to establish manual composition and theoretical basis on henceforth fire inspection and identification.