This paper investigates the mechanism of thermal burn-out and contact welding failures occurring in the master power switches of tracked armored vehicles. Since these tactical vehicles employ a mechanical ON/OFF switching system directly coupled with high-capacity batteries, a transient electrical arc inevitably generates during the brief moment of contact engagement. This arcing causes initial physical and micro-structural damage to the mating upper and lower contact plates. Notably, field data reveals that this failure is highly concentrated in specific production batches, where minor degradation escalates into catastrophic thermal burn-out and contact adhesion (welding). To identify the root cause of this accelerated failure, this study focuses on the causal relationship between the contact area and localized current density. Macroscopic and comparative analysis demonstrates that the defective switches from the problematic production lot possess an effective contact area of only 30% compared to normal, non-defective components. This significant reduction in contact area forces the electrical current to constrict into narrow paths, leading to an sharp surge in local current density and subsequent Joule heating. The combination of initial arc erosion and severe thermal runaway ultimately triggers the melting and welding of the contacts. The findings of this study emphasize that ensuring a sufficient effective contact area is critical in the manufacturing stage of high-current military switches to prevent catastrophic thermal failures under harsh operational environments.

Abstract
1. 서 론
2. 본 론
    2.1 이론적 배경
    2.2 주전원 스위치 고장 현상
    2.3 주전원 스위치 접촉면적 분석
    2.4 접촉면적 변화에 따른 주전원 스위치의 열적소손 모사 시험
3. 결 론
후 기
References

• 김건태(Defense Agency for Technology and Quality) | KIM Keontae Corresponding author
• 나라별(Defense Agency for Technology and Quality) | NA Rabyeol
• 김종식(Defense Agency for Technology and Quality) | KIM Jongsik
• 최동주(Hanwha aerospace cooperation) | CHOI Dongju