Thermal aspects of post-arc recovery dielectric strength of solid insulators

Thermal conditions in the track of an arc on a solid insulator are analyzed from the point of view of the recovery dielectric strength. It is shown quantitatively that feedback from the arc-track can delay the recovery of the residual arc column. Relationships to estimate the temperature diffusion from the “melted” arc-track are presented. These are compared with the temperature decay in the residual arc column. The power flow into the insulation body required for thermal analysis was determined experimentally.