IMPROVEMENT IN THE DURABILITY OF VACUUM-ARC CONTROL DEVICES WITH SWITCHING OF THE RATED CURRENT

The design of contacts with a greater axial magnetic field for vacuum are control devices is described. Axial field specific induction reach es 10 mT/kA, shortening the time of high-current (>10 kA) are transiti on from the contracted to the quasidiffusive state, Are movement on th e contact surfaces is controlled by the radial component of a magnetic field until completion of are transition from the contracted to the q uasidiffusive state. Control of both high-current are states allows a decrease in contact separation speed and thereby an increase by severa l factors in the switching durability of the vacuum are control device with retention of the same short-circuit current interrupting capacit y.