• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.5
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• pp.58-64
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• 2012

In electric power supply systems, an earthing system determines the electric potential of the conductors related to that of the Earth's surface. The choice of earthing system has implications for the safety of the power supply systems. There are considerably different regulations for earthing (grounding) systems in each country. A protective earth(PE) conductor ensures that all exposed conductive surfaces are at the same electric potential as the earth surface. This paper deals with that when PEN conductor of TN-C-S system is disconnected, dangerous touch voltage causes personnel body to be harmed and human being's property to be damaged seriously. For this reason, this paper explains how serious problems can occur when the fault current flows. As a consequence, we can understand how we can design earthing system properly to ensure the personnel safety against earth faults. The result shows the way that TN-C-S system can be applied safely in Korea.

• Proceedings of the KSR Conference
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• 2005.05a
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• pp.767-775
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• 2005

Power Supply System for electric railways is diversified with technical development and is required high technologies. especially, recently there is required many research and development for earthing to ensure safety of people and protection of installations. Generally, leakage resistance is high between rail and ground at tunnel section of subway. because of short circuit of feeding line, earthing interference by transient overvoltage between signals and communication system, and insulation failure, it can damage to human and equipments To minimize these obstacles, earthing equipment is installed at underground section of railway, but it brings about problems in accordance with operate each earthing system to be not enough required protection provisions for electrified railways. This paper proposes effective earthing method to be concerned about installation cost and maintenance. The validity of the proposed earth method is verified by simulation results at underground section of railways.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.8
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• pp.113-120
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• 2014

In this paper, designing of an earthing system in accordance with international standards with regard to 22.9kV-y multi-grounded neutral system is discussed and confirmed that the consumer's earthing system can be a part of a global earthing system by interconnecting its earthing system with the neutral conductor of 22.9kV-y multi-grounded system. Further, it is proposed that some modification of the earthing system design flowchart given in the international standards are necessary when considering the equipotential bonding, lightning protection, and telecommunications facilities as well as the basic safety requirements.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2009.10a
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• pp.59-62
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• 2009

In electrical power supply systems, an earthing system determines the electrical potential of the conductors relative to that of the Earth's conductive surface. The choice of earthing system has implications for the safety of the power supply. Note that regulations for earthing (grounding) systems vary considerably among different countries. A protective earth(PE) connection ensures that all exposed conductive surfaces are at the same electrical potential as the surface of the Earth, This paper investigates that when PEN conductor of TN-C-S system is disconnected, dangerous touch voltage is caused at personnel body. According to this paper, we can understand that when TN-C-S system is applied in Korea, what we should set up to ensure the personnel safety from fault current.

• Proceedings of the KIEE Conference
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• 2009.04a
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• pp.211-212
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• 2009

This Paper present about loop impedance measuring method by a comparison & analysis of the earthing systems in IEC60364. And comparing analysis about only considering a resistance and considering resistance & inductance. Result, For measuring of loop impedance than must measured resistance and reactance. And TT earthing system was lower fault current then TN systems, but an electric shock was higher then TN systems.

• Journal of Environmental Health Sciences
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• v.46 no.1
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• pp.103-109
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• 2020

Objectives: Using as a sleep evaluation tool the Pittsburgh Sleep Quality Index (PSQI), this paper studied the effects of earthing on the amount and quality of sleep by examining a patient population of people who used and did not use earthing mats and a group of general healthy people. Methods: From September to November 2019, 30 patients who voluntarily used an earthing mat, 40 patients who did not use an earthing mat, and 40 healthy people who did not use an earthing mat were selected. A questionnaire applying the PSQI (Pittsburgh Sleep Quality Index) after being translated into Korean was distributed starting November 29, 2019 to 110 subjects. Out of them, 101 subjects who completed the questionnaire were examined. All statistics used SPSS 25.0. Results: The first overall score showed that all three groups had problems sleeping, with five points or more, but the general population had better sleep quality than the patient group. It also showed that the using matgroup had better quality of sleep than the ones that did not use the earthing mat In addition, the analysis of the third group through the variance analysis showed significance at >0.05 for the general population and the patient group. Based on this, a multi-comparison analysis of the third group showed significantly less than 0.05 in patients who do not use an earthing mat compared to the public. First of all, there are no statistically significant differences between the three groups in subjective sleep quality, sleep latency, and sleep time, but an analysis of multiple comparison analysis with the general population group showed that the quality of sleep was worse compared to those that used the mat. In addition, sleep efficiency, sleep disorder, sleeping pills, and daytime dysfunction were found to be less than >0.05 in the three groups. Conclusions: These results suggest that if you ground your body to Earth during sleep, the secretion of cortisol will decrease night levels, sync more with the natural 24-hour circulation rhythm profile, and that when you sleep, sleep is better and pain and stress are associated with the study. While the preceding study cannot confirm that contact with the ground affects the quality of sleep, it suggests that it is relevant as shown in this paper.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.8
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• pp.50-55
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• 2012

Grounding is very important for electrical safety. But it is very difficult to secure enough space for the installation and management of grounding in the city because of the congestion of the buildings. Therefore, to solve this problem, this paper suggest structure-grounding application taking advantage of building structure as protective grounding. And, to verify its feasibility, this paper shows the result to measure and analyze grounding-resistance of structure for 12 buildings mainly structed in the city.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.3
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• pp.39-45
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• 2010

This paper deals with investigation on the spot for grounding systems of buildings based on international standards at construction sites. The investigation was carried out for grounding method, grounding type, shape of grounding electrode, grounding for a lightning protection system, continuity of steelwork in reinforced concrete structures, etc. The investigation on the spot was performed by a researcher and engineer with over fifteen years of industry experience all over the country. As a result of the investigation on the spot in 13 buildings, common grounding and structure grounding methods were dominant. The safety improvement methods include installation of equipotential bonding conductors for the connection to the main earthing terminal, equipotential bonding conductors for supplementary bonding, use of Surge Protective Devices (SPD), and safe connections between earthing conductors and the rebar.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1063-1064
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• 2008

Bimodal tram has a carbody made of polymer composite material which is good electrical insulator. As an series hybrid type, Alternating voltage generated from generator coupled with CNG engine are rectified and transformed to variable voltage ranges which are applied to electrical apparatus and ECUs equipped inside of the tram. The failures of electrical insulation between high voltage($400V{\sim}800V$) and low voltage(24V) or between different kind of voltages such as AC and DC may cause some electrical interferences to prevent from operating rightly and other safety problem. This paper have investigated about the degradation factors of the electrical insulation and the earthing method available to bimodal tram, which is effective for preventing the electromagnetic interference coming from the inside or outside of tram but need some detecting measurements of earth leakage through electrical systems.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.2216-2217
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• 2008

This paper write about earth system for the prevention electric shock and a protection of equipment in england. The IEC60364 and BSI(British Standards Institution) define earthing method(IT, TT, TN-C, TN-S, TN-C-S)-BSI is british standards and in case of england almost use the TN system. TN system can classify TN-S & TN-C-S(PME). The findings on survey in england are used the TN-S system and TN-C-S system about 70% and residue 30% are used TT system and IT system from the exiting state of things.