Arc motion and pressure formation in low voltage switchgear

To understand the complex nature of are motion in current limiting low-voltage switchgear detailed information about the interaction between pressure distribution, are movement and plasma flow are necessary. One of the major factors concerning these interactions is the geometry of the are chamber, Systematic experimental investigations have been carried out to study the influence of the gap between the are runners and the insulating side walls of the are chamber in combination with different outlets at the top of the chamber. A high time resolution optoelectronic measuring device for the observation of are motion, and pressure transducers at different positions of the chamber give a good impression of each stage of are movement and the corresponding pressure development. Significant differences depending on the geometry of are chambers can be shown. The findings are explained quantitatively and qualitatively.