Phenomena generated by splitter plates on low-voltage electric arc dynamics

The breaking of an electric arc is obtained by its lengthening, its splitting up and its cooling in the quenching chamber made up of fins called splitters. However, the latter sometimes have unwanted effects. The presented study deals with the phenomena generated by their presence and their influence on the arc behaviour. The arc is observed thanks to a tool called "magnetic camera" based on the measurement of the magnetic field outside the device. For a given time, the magnetic picture allows the reconstitution of the average current line that represents the arc. Several tests were carried out with a quenching chamber consisting of iron splitters and prospective peak currents varying from 1370 A to 6300 A. Two configurations of positioning were studied. The first one consists in putting three tilted splitters located at the same level; the second one is made up of four splitters, each with a shifted position compared to the others. Other parameters are also analyzed: arc voltage, current limiting, thermal stress, energy, break time. In general, the arc enters the quenching chamber where it is split. However, for high currents, it does not put out quickly after penetrating the splitters but oscillates for a few moments in front of them.