The process of arc splitting between metal plates in low voltage arc chutes

The behavior of arcs in low voltage switching devices is affected by several interactions. For studying simple arrangements of arc runners without metallic splitter plates ("deion plates") a three-dimensional simulation system has already been developed. It takes into account the plasma fluid dynamics, the current flow within the electrodes and the plasma, and the magnetic field generated by both currents. In order to model the arc splitting process simulations with an insulating barrier were done in a first step. For the simulation of the splitting process between metallic deion-plates the simulation model has to be extended. In experiments including high-speed movies it is shown that this process is a continuous transition of current flow from the still undivided arc to the new arc roots formed on the metal plates. A new simulation model representing the roots by a thin layer of current-dependent resistivity is discussed and simulation results are compared with switching experiments