Fire Science and Engineering (한국화재소방학회논문지)

Korean Institute of Fire Science and Engineering (한국화재소방학회)
권호 표지
DOI QR코드

DOI QR Code

Analysis of the Risk of Heat Generation due to Bolt Loosening in Terminal Block Connector Parts

볼트풀림에 의한 터미널 블록의 접속부 발열 위험성 분석

  • Yeon, Yeong-Mo (Research Division, METIS) ;
  • Kim, Seung-Hee (Dept. of IT Convergence Software Engineering, Korea Univ. of Technology & Education)
  • 연영모 ((주)메티스) ;
  • 김승희 (한국기술교육대학교 IT융합SW공학과)
  • Received : 2020.03.12
  • Accepted : 2020.04.09
  • Published : 2020.06.30
Download PDF
⟨ Previous Next ⟩

Abstract

In this study, the risk of heat generation due to normal and overload currents that vary with the abnormal loosening angle of wire-connecting bolts were identified. The risks were analyzed based on the thermal characteristics to minimize the carbonization accidents of terminal blocks inside distribution panels typically used in industrial sites. We applied a method for measuring the heating temperature and temperature variations in the terminal blocks in real-time by installing a resistance temperature detector sensor board in the terminal block. The experimental results showed that the terminal block model with a low-rated current exhibited a higher heating temperature, thus, confirming the need to select the terminal block capacity based on load currents. Additionally, the higher the rated current of the terminal block with a high-rated current and the higher the degree of loosening, the faster the carbonization point. Such heating temperature monitoring enabled real-time thermal temperature measurement and a step-by-step risk level setting through thermal analysis. The results of the measurement and analysis of carbonization risks can provide a theoretical basis for further research regarding the risk of fire due to carbonization. Furthermore, the deterioration measurement method using the temperature sensor board developed in this study is widely applicable to prevent fires caused by poor electrical contact as well as risk-level management.

본 연구는 산업현장에서 사용되는 분전반 내 터미널 블록의 탄화 사고를 예방하기 위한 목적으로, 전선 접속부 볼트의 이상(Abnormal) 풀림 각도에 따라 변화하는 정상전류 및 과전류의 접속부 발열 위험성을 확인하고 열적 특성을 통해 위험성을 분석하였다. 이를 위하여 터미널 블록에 Resistance temperature detector (RTD) 센서 보드를 설치하여 실시간으로 터미널 블록의 발열 온도와 온도의 변화를 측정하는 새로운 기법을 적용하였다. 실험 결과 정격 전류가 작은 터미널 블록 모델의 발열 온도가 높게 나타남에 따라 부하전류에 따른 터미널 블록 용량 선정의 중요성을 확인하였다. 또한 정격전류가 높은 터미널 블록의 정격 전류가 높을수록, 이상 풀림 정도가 클수록 탄화점이 빨라짐을 확인하였다. 이러한 발열 온도 모니터링을 통해서 실시간 발열 온도를 측정할 수 있었고 열적 분석을 통해서 단계별 위험수위 설정이 가능함을 확인할 수 있었다. 본 연구의 탄화 위험성 측정 및 분석 결과는 탄화로 인한 화재 위험성에 대한 응용 연구의 이론적 기초를 제공할 수 있다. 또한 본 연구에서 새롭게 적용한 온도 센서 보드를 활용한 열화 측정 방법은 위험수준관리 및 전기적 접촉 불량으로 인한 화재 예방 활동에 광범위하게 적용 가능할 것으로 사료된다.

Keywords

References

  1. D. K. Kwak, S. H. Choi, Y. J. Park and J. H. Kim, "A Study on Smart Distribution Panel for Electrical Fire Prevention", Journal of the Korean Society of Hazard Mitigation, p. 245 (2015).
  2. Naver, "Terminal Block, Electronic Terminology Dictionary", Editorial Board of a Monthly Electronic Technologies (1995).
  3. S. K. Kim, S. W. Jee, S. M. Park and C. H. Lee, "A Study on the Thermal Characteristics of Wire Connection Part Depending on the Screw Torque", Journal of Korean Institute of Fire Science & Engineering, Vol. 26, No. 4, pp. 82-88 (2012).
  4. D. H. Kim and D. K. Hwang, "Analysis of Electrical and Thermal Signal for Series Arc in Electrical Contact", Journal of the Korean Society of Safety, Vol. 30, No. 5, pp. 1-7 (2015). https://doi.org/10.14346/JKOSOS.2015.30.5.1
  5. T. W. Kim, C. H. Park and S. I. Lee, "Characteristics & Fire Risk in Accordance with the Series Arcing in the Connecting Portion of the Circuit Breaker", Journal of the Korean Institute of Electrical Engineers, Vol. 2016, No. 7, pp. 1553-1554 (2016).
  6. D. W. Kim, K. Y. Lee, H. W. Moon, H. K. Kim and C. S. Choi, "Research on Overheat Protection Techniques of Connection Parts of MCCB by Poor Contact", Journal of Korean Institute of Fire Science & Engineering, Vol. 22, No. 4, pp. 54-60 (2008).
  7. N. Hadziefendic, N. Kostic, J. Trifunovic and M. Kostic, "Detection of Poor Contacts in Low-Voltage Electrical Installations", IEEE Transactions on Components, Packaging and Manufacturing Technology Vol. 9, No. 1, pp. 129-137 (2018). https://doi.org/10.1109/tcpmt.2018.2882626
  8. N. Hadziefendic, J. Trifunovic and M. Kostic, "Effects of a Reduced Torque on Heating of Electrical Contacts in Plugs and Receptacles", IEEE Transactions on Components, Packaging and Manufacturing Technology, Vol. 8, No. 11, pp. 1905-1913 (2018). https://doi.org/10.1109/TCPMT.2018.2827080
  9. IDEC, "BN-W/BNH-W Series Terminal Blocks", pp. 1-5, http://www.idec.com, Accessed Feb. 17 (2020).
  10. N. Hadziefendic, M. Davidovic, V. Djordjevic and M. Kostic, "The Impact of an Incomplete Overlap of a Copper Conductor and the Corresponding Terminal on the Contact Temperature", IEEE Transactions on Components, Packaging and Manufacturing Technology, Vol. 7, No. 10, pp. 1644-1654 (2017). https://doi.org/10.1109/TCPMT.2017.2720421