Dynamics of glowing contacts triggered by poor electrical contact
ZHANG Jing1, CHEN Tao1, HUANG Lida1, SU Guofeng1,2, SUN Zhanhui1, CHEN Jianguo1
1. Institute of Public Safety Research, Department of Engineering Physics, Tsinghua University, Beijing 100084, China; 2. Hefei Institute for Public Safety Research, Tsinghua University, Hefei 230601, China
Abstract:Glowing contacts triggered by poor electrical contact are one of the most important ignition sources for fires. The glowing contacts with high temperature are commonly hidden in electric wires. The glowing contact involves complex coupling between the copper oxidation, heat transfer, and electric field. The relationships between the key parameters are investigated experimentally by measuring the growth rate of the oxide bridge length as well as the glowing contact resistance and temperature. The results show that the oxide bridge length and the glowing contact resistance increase with time. The maximum contact temperature increases with time up to 1 400-1 600℃. Increasing currents increase the oxide bridge growth rate and growth time. The increasing rate of the resistance first increases and then decreases with the current increase. The results further show that the glowing contact is due to interactions between the oxidation extent, the changes in the copper oxide resistivity with the current, and the increases in the specific heat with temperature.
[1] LUO Y X, LI Q, JIANG L R, et al. Analysis of Chinese Fire Statistics during the period 1997-2017[J]. Fire Safety Journal, 2021, 125:103400. [2] 雷瑞军, 马玄. 电气火灾统计分析研究[J]. 武警学院学报, 2014, 30(6):15-17. LEI R J, MA X. The statistical data analysis on features of electrical fire[J]. Journal of Chinese People's Armed Police Force Academy, 2014, 30(6):15-17. (in Chinese) [3] 邸曼. 电气火灾高发原因[Z/OL]. (2017-09-01)[2021-12-15]. https://mp.weixin.qq.com/s/Z4f3UoWFyhco1DkiWPU9qA. DI M. The most frequent cause of electric fire[Z/OL]. (2017-09-01)[2021-12-15]. https://mp.weixin.qq.com/s/Z4f3UoWFyhco1DkiWPU9qA. (in Chinese) [4] WANG Q J, CHUNG Y W. Encyclopedia of tribology[M]. Boston, USA:Springer, 2013. [5] 新宮博康, 鷲見哲雄, 高橋司. 導体接続部におけるホットゾーン成長現象[J]. 電気学会論文誌A, 1986, 106(11):519-524. DOI:10.1541/ieejfms1972.106.519. SHINGU H, SUMI T, TAKAHASHI T. Hot zone growing on electric contacts[J]. The Transactions of the Institute of Electrical Engineers of Japan. A, 1986, 106(11):519-524. DOI:10.1541/ieejfms1972.106.519. (in Japanese) [6] 新宮博康, 鷲見哲雄, 内田悦行, 等. 直流12 V回路における導体接続部のホットゾーン[J]. 電学論A, 1997, 117(2):186-192. DOI:10.1541/ieejfms1990.117.2_186. SHINGU H, SUMI T, UCHIDA Y, et al. Hot-zone phenomena on electric contacts in D.C. 12 Volt line[J]. IEEJ Transactions on Fundamentals and Materials, 1997, 117(2):186-192. DOI:10.1541/ieejfms1990.117.2_186. (in Japanese) [7] 新宮博康, 鷲見哲雄, 内田悦行, 等. 電気回路接続部に発生するホットゾーン現象[J]. 溶接学会論文集, 2000, 18(4):651-656. DOI:10.2207/qjjws.18.651. SHINGU H, SUMI T, UCHIDA Y, et al. The hot zone phenomenon which occurs in the electric circuit[J]. Quarterly Journal of the Japan Welding Society, 2000, 18(4):651-656. DOI:10.2207/qjjws.18.651. (in Japanese) [8] SHEA J J. Glowing contact physics[C]//Proceedings of the 52nd IEEE Holm Conference on Electrical Contacts. Montreal, Canada, 2006:48-57. [9] SLETBAK J, KRISTENSEN R, SUNDKLAKK H, et al. Glowing contact areas in loose copper wire connections[J]. IEEE Transactions on Components, Hybrids, and Manufacturing Technology, 1992, 15(3):322-327. [10] KIM D O, KIM H K, SHONG K M, et al. The properties of oxidation growth and overheating by poor contact[C]//Proceedings of the IEEE 8th International Conference on Properties & Applications of Dielectric Materials. Bali, Indonesia, 2006:392-395. [11] URBAS J. Glowing connection experiments with alternating currents below 1 Arms[J]. IEEE Transactions on Components and Packaging Technologies, 2010, 33(4):777-783. [12] SHEA J J, ZHOU X. Material effect on glowing contact properties[C]//Proceedings of the 53rd IEEE Holm Conference on Electrical Contacts. Pittsburgh, USA, 2007:90-97. [13] HAGIMOTO Y, KINOSHITA K, HAGIWARA T. Phenomenon of glow at the electrical contacts of copper wires[J/OL].[2021-12-22]. National Research Institute of Police Science Reports:Research on Forensic Science, 1988, 41(3):30-37. https://www.tcforensic.com.au/docs/japan/3.html. [14] [XC14-1.tif,JZ] [XC14-2.tif,JZ] [XC14-3.tif,JZ] 2000:1513-1515. CHOI C S, KIM H K, KIM H R, et al. The relation between Cu2O growing velocity and current of copper wire[C]//Proceedings of 2000 Spring Academic Paper Conference of the Korean Safety Society. South Korea, 2000:1513-1515. (in Korean) [15] [XC15-1.tif,JZ] [XC15-2.tif,JZ], 2006, 55(3):146-152. CHOI C S, KIM H K, KIM D O, et al. The analysis of voltage waveform and oxidation growth of conductor with series arc[J]. The Transactions of the Korean Institute of Electrical Engineers, 2006, 55(3):146-152. (in Korean) [16] [XC16-1.tif,JZ] [XC16-2.tif,JZ], 2019, 34(3):15-20. KIM W, PARK S, HWANG D. The heating of Cu-oxide and arc properties according to electrical poor contact[J]. Journal of the Korean Society of Safety, 2019, 34(3):15-20. (in Korean) [17] NIST Chemistry WebBook. Copper oxide[Z/OL].[2021-12-22]. https://webbook.nist.gov/cgi/cbook.cgi?ID=C1317380&Type=JANAFS&Table=on.