Abstract
DC surface tracking has been investigated in three different polymer insulation materials; polystyrene, glass fiber reinforced polyamide, and a polyphenylene oxide and polystyrene compound, based on the experimental test set-up in IEC 60112. Experiments focused on the behavior of insulation material surfaces subjected to 1 kV DC while exposed to salt water with 0.002wt% and 0.01wt% NaCl. The results showed that higher salt concentrations resulted in more severe arc formation, tracking marks and erosion in all three materials tested. When comparing the sample surfaces with the arc formation observed during testing, the intensity and magnitude of arc formation correlated with the severity of the resulting tracking and erosion. Results showed that PPO and PS samples exhibited significant tracking and erosion, especially with higher concentrations, while PM samples displayed greater resistance. The findings underscore the importance of understanding service conditions for insulation materials in maritime DC applications and that selecting the correct insulation material can increase electrical safety and reliability.