ARC-WALL INTERACTION MODELING IN A LOW-VOLTAGE CIRCUIT-BREAKER

A hydrodynamic model for electrical are modelling is used to study the interaction between the electrical are and the sidewall in a low-volt age circuit breaker. The interaction model is based on an energy balan ce at the boundary. Comparisons of pressure, are voltage and ablated m ass between computations and experiments validate the model. The resul ts confirm that the main mechanism at the sidewall is the photo-ablati on. The model shows that, very rapidly, plastic vapours replace the ai r in the circuit breaker and are responsible for a residual conduction in the are initiation region.