The problems of calculation the arc switching time in tulip contact switches

The amount of heat power delivered to contacts as the result of electric arc ignition before metallic touching of contacts depends on electric circuit parameters, as well as on the size and velocity of change of the contact gap. The make arc duration depends hence on the value of the intensity of electric field in the contact area, and on the velocity of contacts closing. In general, the higher the value of velocity of contact closing in an electric switch, the shorter the turn-on time. Resulting is shorter time of arc duration that enhances a longer life of the electric switch. High velocity has a negative aspect as it causes rebounding of contacts. The paper describes the problems of calculation the arc switching time in contact switches during making of a current in current paths and test circuits.