Optimized design for thermoplastic side walls for arc chambers used in circuit breakers applications

This paper focuses on the optimized design of a one-piece arc chamber based on a fiberglass arc stack that is commonly used in industrial circuit breakers. The current design is an arrangement of plates in a fan pattern shape stacked with fiberglass walls and, the new design uses a thermoplastic injected housing with a parallel pattern for the metal plates, with the additional benefit by reducing the number of plates. A dynamic simulation was performed to represent the on-off movement of the blade to define important parameters to extinguish the electric arc as arc plate distance and orientation. Thought the simulation and several interactions, the final design was made using additive manufacturing to evaluate the arc motion by a high-speed camera. The optimized design was injected using thermoplastic Nylon and tested following sequences under the UL 489 standard to study the functionality of the proposal. The obtained parameters in these experiments were analyzed statistically, to compare both designs. The performance of the proposed design was followed in terms of the metal plates erosion, related with the arc distribution during arc extinction on a short circuit.