Optical and magnetic diagnostics of the electric arc dynamics in a low voltage circuit breaker

The study presented concerns the behaviour of an electric high current and low voltage breaking arc. The arc dynamics in a circuit breaker is analysed according to two diagnostic methods. A magnetic diagnostic based on precise measurements of induction restores the average line of current that magnetically represents the arc. This method is compared to an optical diagnostic using a high-speed mechanical camera and a CCD camera. These methods allow us to follow the movement and shape of the arc and to study the influence of the quenching chamber on the break quality. This quenching chamber is composed of splitter plates whose material can been varied.