Study of Arc Mobility and Reignition in a Static Gap Discharge with Magnetic Field
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Microstructure effect on reignition and welding properties of copper-tungsten electric contact
Copper-tungsten contacts are frequently used in high power circuit breakers and contactors in air, oil, SF/sub 6/, or vacuum. Arc interruption and anti-welding properties are important design parameters. In this study, we examined the effects of tungsten particle size on reignition and weld resistance in air. Oxidation and mechanical properties are also determined to find the optimum contact properties for arc erosion under thermal and mechanical stresses. Static gap arc erosion is used to supplement observations in a dynamic weld test. This avoided device mechanical variables that affect contact erosion.
Use of an inverse method on the determination of the evolution of a self-blown electric arc in the air
An inverse method for studying the dynamic behavior of a low-voltage arc column is presented. A small number of microcoils are placed at suitably chosen points. The measured inductions are recorded during the whole arc life, and the evolution curves of the position of the anodic and cathodic roots, as well as those of the arc column gradient, assumed to be threadlike, can be obtained analytically. From such results it is easy to define the speed and acceleration of the anodic and cathodic roots, allowing the column behavior to be defined during the entire blowing phase. Moreover, the geometry of the breaking device is the only factor that must be taken into account. >