| 摘要 |
PURPOSE:To improve the breaking performance on opened poles nearby at the time of the current peak by uniformly providing disk-shaped protruded contact sections with the same height over the peripheral direction at positions slightly outside than the outer diameter size of lead bars on the surfaces of plane electrodes and specifying the number, diameter and height of them to constitute at least one electrode. CONSTITUTION:Disk-shaped protruded contact sections 14a and 15a with the same height are uniformly provided over the periphery direction at positions slightly outside than the outer diameter size of lead bars on the surfaces of electrodes 14 and 15 having nearly plane surfaces, the number of the protruded contact sections 14a and 15a is set to 3-6, the diameter is set to 3-8mm, and the height is set slightly smaller than the diameter to constitute at least one electrode. The electrodes 14 and 15 are brought into contact with each other via the protruded contact sections 14a and 15a of one electrode, thus they are in contact at least at three points, as a result distributed arcs occur at the contacts, the magnetic driving force in the radial direction is applied to these arcs and moves them to the arc diffusion section on the periphery. The preset breaking can be satisfactorily performed on opened poles at the peak time of a large current. |
