Comparison of spherical and axisymmetric models of electrical contact heating and the conditions of their application

Two mathematical models, spherical and axisymmetric, describing the temperature field in closed electrical contacts are compared and the rightness of their application is discussed. The ranges of the contact radius, time and current are determined for which one or another model could be applied with the required accuracy. The temperature field in the axisymmetric model is found in the form of alternative series where the first term represents the solution in the spherical model. It enables us to estimate the error in calculation of the temperature using the spherical model with respect to the axisymmetric model. Some applications to the experimental data are considered.