Maximum interrupting Capacity of CuCr Contacts under the effect of uniform axial magnetic field (AMF)

Maximum interrupting capacity of the butt CuCr 70/30 contacts at external uniform AMF has been experimentally investigated for AMF induction range 0-1.2 T. It has been found that dependency of maximum interrupting current density versus AMF induction has a tendency to saturate when the latter achieves the level of the first characteristic point B1 on Volt-Tesla characteristic. Radial energy losses have been evaluated on the basis of measured anode mass losses. 1D thermal model has been used for evaluation maximum interrupting current density. At the same time radial energy losses have been taken into consideration. Calculated results demonstrate good agreement with the experimental data if critical temperature equal to ~2000 K is considered. This value of critical temperature is supported by several experiments described in literature