Simulation of the thermal radiation effect of an arc on polymer walls in low-voltage circuit breakers

A model of sputtering (ablation) of polymer walls caused by the thermal effect of an arc in low-voltage circuit breaker is suggested. The model takes into account heating, volume thermal decomposition, and fusion of the polymer, as well as the screening action of the vapor from the surface. The ablation of the walls is due to the UV component of the arc radiation, most of which is absorbed in the vapor. It is shown that the ablation conditions change drastically with distance to the center of the arc. The parameters of the reaction zone and of the area occupied by the melted polymer are estimated.