Forming the Are at Opening contacts and Arc Extinction by External Magnetic Force

접점 개방시 아크 형성과 외부자계에 의한 효과적인 아크 소호

This paper compare the Townsend theory with the Molten metal bridge theory of Holm for the arc discharge at opening contacts. And we measured the arc voltage at opening contacts of the 3 types arc extinction unit used in DC magnetic contactor. So, we sure that the molten metal bridge contributes to form the arc. By the experiment of the 3 types arc extinction unit, we know that the magnetic force acting on the arc doesn't effect forming arc but contribut the arc extinction.