• Fire Science and Engineering
• /
• v.31 no.3
• /
• pp.63-72
• /
• 2017

This study fabricated a low-voltage 10 circuit distribution board based on the KEMC (Korea Electrical Manufacturers Cooperative) 2102-610 standard and performed a characteristics assessment of the developed 10 circuit distribution board to secure product stability. The developed 10 circuit distribution board is designed to have the characteristics of insulation materials, as well as resistance to corrosion ultraviolet radiation and mechanical impact. The developed distribution board is fabricated to have an appropriate protection class of enclosure, electric shock prevention and protection circuits, switchgear and its components, internal electrical circuits and connectors, external conduct terminal, insulation characteristics, temperature rise test, heat resistance, etc. The developed 10 circuit distribution board consists of a single phase circuit and 3-phase circuits. It is possible to measure in real time the leakage current generated from the load distribution line by installing a sensor module at the load side of each of the branched switchgears. In addition, it is possible to increase a circuit according to the use and purpose of the load and to also manage and check the load in real time. Temperature rise tests were performed on the developed 10 circuit distribution board at 18 places including the inlet connection, main circuit and distribution circuit bus bars and bus bar supports, etc. The highest temperature of $65.3^{\circ}C$ was measured at the R-Phase of the connection of the MCCB power supply for the branch circuit bus bar and a temperature rise of $61.6^{\circ}C$ was measured at the T-Phase of the load side. When applying thermal stress to an MCCB for 6 hours at $180^{\circ}C$ using a heat resistant experimental device, it was found that the actuator lever was transformed and moved in the tripped state.

• Proceedings of the KIEE Conference
• /
• 2015.07a
• /
• pp.872-873
• /
• 2015

여러 전력기기를 안전성과 편의성 등을 위하여 함(enclosure)에 설치하였을 때, 이러한 제품을 배전반(Switchgear and controlgear assemblies)이라고 한다. 내부에 설치되는 기기들을 서로 접속할 때 전선(cable) 또는 부스바(busbar)를 사용하고 있는데, 사용시 필연적으로 전력손실에 의한 발열로 인하여 배전반 내부온도 및 기기의 온도가 상승한다. 기기에 대한 온도 상승 허용범위는 각 기기의 해당규격에 규정되어 있으며 배전반 규격(고압배전반 : IEC 62271-200 및 SPS-KEMC 2101-0609, 저압배전반 : IEC 61439 series 및 SPS-KEMC 2102-0610)에는 외부접속용 단자 등 배전반 내부에 사용되는 전선 또는 부스바의 온도상승 허용범위가 규정되어 있다. 본 고찰에서는 배전반의 각 정격전류에 따른 전선 또는 부스바의 사이즈, 특히 부스바의 사이즈 및 형상에 따른 온도상승의 영향을 살펴보고자 한다.

• Journal of the Korean Society of Safety
• /
• v.33 no.5
• /
• pp.21-27
• /
• 2018

The purpose of this study is to develop a SOP (Standard Operating Procedure) for a distribution board that can monitor the leakage current of a load distribution line in real time. The developed distribution board was fabricated by applying IEC 61439-1. It consists of the distribution board and an alarm device. The work process for making the distribution board was compliant with the KEMC (Korea Electrical Manufacturers Cooperative) regulations. And the AC distribution board range is 1,000 V. In addition, the voltage in DC is less than 1500 V. The distribution board receives a 3-phases and 4-wires power supply system and can supply power to the load of a maximum of 32 single or three phase distribution circuits. Also, leakage current measured on the power distribution board was used by sensors installed. The SOP of the developed distribution board consists of the installation standards for the short circuit alarm device and sensor, the surge protection device, switches and indication lamps, and other devices. The operation procedure was prepared so that each manufacturing step of the distribution board must be confirmed by the persons in charge of preparation, production, quality control and approval before moving forward to the next step.

• Proceedings of the KIEE Conference
• /
• 2011.07a
• /
• pp.896-897
• /
• 2011

저압배전반(Low-voltage switchgear and controlgear assemblies)에 관한 대표적인 국제규격으로는 IEC 60439 시리 가 있어(국내규격으로는 KEMC(한국전기공업협동조합 단체규격) 2102), 저압배전반의 형식시험(Type test)시 이 규격을 적용하여 시험하고 있으나, 최근 IEC 60439 시리즈의 규격 개정작업이 진행되고 있다. 본 고찰에서는 새로 제정된 61439 시리즈의 주요 내용을 개략적으로 소개하여, 신 규격에 의한 배전반 형식시험에 도움을 주고자 한다.

• Review of Culture and Economy
• /
• v.19 no.2
• /
• pp.147-170
• /
• 2016

This study has identified the current status and challenges to development of Korean Ethnic Media Companies in North America, China, and Australia New Zealand and aimed to understand implication of cultural policy. It examines the media circumstances, business resources of Korean Ethnic Media Companies(KEMC), and Korean ethnic broadcasting aid project which is operated for 10 years, and interviewed nine CEOs' of KEMC. According to the analysis, KEMCs in North America are in the market which is fully exposed to competition. China's KEMCs are the "limitedly localized market" which is supported by the government's regulatory for minority media. Australia & New Zealande's KEMCs are the market which potential growth is expected. North American KEMCs are needed to upgrade the business structure and organizational resources for content differentiation. China's KEMCs have to diversify financial resources and to consolidate content power. and Australia & New Zealande's KEMCs need support & cooperatation from home country for ensuring high-quality content.

• Korean Journal of Microbiology
• /
• v.43 no.1
• /
• pp.66-71
• /
• 2007

Two isolates of genus Acinetobacter were obtained from Jang-Baek waterfall in North Korea. Morphological characteristics of the isolated 2 strains were Gram-negative, aerobic and rod shape bacteria. Physiological and biochemical characterization of the isolated 2 strains were some different aspect from those of type strains. 16S rDNA sequence analysis showed that the two isolates shared 99.9% sequence similarity. Strains JB10 and $JB15^{T}$ were shown to belong to the Gammaproteobacteria and showed the highest levels of sequence similarity to Acinetobacter tandoii $4N13^{T}$ (97.3%), Acinetobacter haemolyticus $ATCC17906^{T}$ (97.2%), Acinetobacter johnsonii $DSM6963^{T}$ (97.2%), Acinetobacter junii $DSM6964^{T}$ (96.7%), Acinetobacter schindleri $LUH5832^{T}$ (97.0%) and Acinetobacter ursingii $LUH3792^{T}$ (96.6%). The major cellular fatty acid in Acinetobacter type strains and isolated strains included $C_{18:1}\;{\omega}9c\;and\;C_{16:1}\;{\omega}7c/C_{15:0}\;iso\;2OH$. Eventhough it was ascertained that the isolated strains were closely related to genus Acinetobacter, physiological and biochemical characteristics and the result of the isolated strains 16S rDNA analysis indicate some different aspects from those of type strains of genus Acinetohacter It is considered that the isolated JB10 (=KEMC 52-093) and $JB15^{T}\;(=KEMC\;52-094^{T})$ strains be new species of genus Acinetobacter. We name it as Acinetobacter koreensis sp. nov.

• Proceedings of the KIEE Conference
• /
• 2000.07a
• /
• pp.191-193
• /
• 2000

In this paper, being different from traditional methods, we design digital protective relay which can be applied to power management and control systems of not only small and medium but also a large scale plants. The digital protective relay was designed with DSP CPU(TMS320C31) to protect and measure more quickly and precisely. We will present test result which it performed according to the standards of Korea Electrical Manufactures Cooperative to prove the faculties of digital protective relay. The test result on the basis of KEMC1120 and IEC60255, show that the operation time error of the digital motor protection relay is improved within ${\pm}5%$.

• Journal of the Korean Society of Industry Convergence
• /
• v.4 no.3
• /
• pp.263-266
• /
• 2001

In this paper, intelligent methods using digital protection relay in power SCADA system is developed in order to protect power systems by means of timely fault detection during operation and control at starting for induction motor which have various load environments and capacities in power systems. The digital protective relay was designed with DSP CPU(TMS320C31) to protect and measure more quickly and precisely. The test result on the basis of KEMC 1120 and IEC60255, show that the operation time error of the digital motor protection relay is improved within ${\pm}5%$. Also, we can control motors at starting according to starting types with simple method as programmable sequence editor. So we can improve the demerits of high cost and much manhour for rework.

• Journal of the Korean Society of Safety
• /
• v.32 no.3
• /
• pp.15-20
• /
• 2017

This study presented the strength of the materials and parts for smart distribution board fabrication, and developed a work operation process chart for smart distribution board fabrication. This work operation process chart for smart distribution board fabrication complied with SPS-KEMC regulations, and the applicable range and object are less than 1,000 V and 1,000 Hz for the AC distribution board and less than 1,500 V for the DC distribution board. The power supply is 3 phase 4 wires ($3{\Phi}$ 4W), divided into a single phase circuit and a 3 phase circuit. In addition, the circuit was configured so that the leakage current flowing through the distribution line of the load could be monitored in real time by using the sensor module installed at the rear end of the circuit breaker. Therefore, the administrator can easily find the risk factor of the load since engineer can check the leakage current of each distribution line. In addition, if a leakage current greater than standard value flows, it is possible to generate an alarm against a short circuit and cut off the leakage current. The work operation process chart for the smart distribution board fabrication consists of the following steps: raw and subsidiary materials, sheet metal work, tube making, welding, painting, busbar fabrication, assembly and wiring, product inspection, shipment, etc. Moreover, symbols, ${\Delta}$, ${\nabla}$, ${\bigcirc}$, ${\Rightarrow}$, etc. were used according to the type of work and work progress so that workers can easily understand the progress of the work.

• The Transactions of the Korean Institute of Electrical Engineers A
• /
• v.49 no.10
• /
• pp.516-523
• /
• 2000

In this paper, intelligent methods using digital protective relay in power supervisory control system is developed in order to protect power systems by means of timely fault detection and diagnosis during operation for induction motor which has various load environments and capacities in power systems. The spectrum pattern of input currents was used to monitor to state of induction motors, and by clustering the spectrum pattern of input currents, the newly occurrence of spectrums pattern caused by faults were detected. For diagnosis of the fault detected, the fuzzy fault tree was derived, and the fuzzy relation equation representing the relation between an induction motor fault and each fault type, was solved. The solution of the fuzzy relation equation shows the possibility of each fault's occurring. The results obtained are summarized as follows: 1) The test result on the basis of KEMC1120 and IEC60255, show that the operation time error of the digital motor protective relay is improved within ${\pm}5%$. 2) Using clustering algorithm by unsupervisory learning, an on-line fault detection method, not affected by the characteristics of loads and rates, was implemented, and the degree of dependency by experts during fault detection was reduced. 3) With the fuzzy fault tree, fault diagnosis process became systematic and expandable to the whole system, and the diagnosis for sub-systems can be made as an object-oriented module.