<p>This study aimed to analyze the factors contributing to insulation degradation and tracking phenomena in low-voltage circuit breakers, as fire incidents due to these issues are frequent. Accelerated aging tests were conducted on low-voltage circuit breakers, and component analysis of the insulation material after aging was performed. Moreover, the status of the circuit breakers subjected to accelerated aging was compared with that of aged circuit breakers. Fourier transform infrared spectroscopy (FT-IR) was used to quantitatively evaluate the polymer components, and thermal analysis was employed to assess the recrystallization index of the polymer materials. The analysis revealed that the circuit breakers subjected to accelerated aging did not exhibit polymer bonding structure degradation, whereas in circuit breakers older than 20 years, polymer bonding structure degradation was observed. Furthermore, the aged circuit breakers with degraded polymer bonding structures exhibited lower insulation resistance than the non-degraded circuit breakers. Moreover, tracking tests revealed that tracking phenomena occurred at voltages lower than the standard operating voltage in the aged circuit breakers.</p>