Abstract
The mathematical model describing the dynamics of temperature field in electrical contacts at the initial stage of a blow-off repulsion is presented. It is based on the Stefan problem for the disk of a short arc and two spherical domains for the liquid and solid zones. All coefficients in the equations such as the thermal and electrical conductivities, density, thermal capacity are dependent on the temperature. The analytical solution of this problem is obtained using the similarity principle. The results of calculation are compared with the data obtained in published papers and with the experimental data.