Key blocks for circuit breaker

摘要

A molded case circuit breaker is provided. Key blocks with a key shaped projection along one side are received in key shaped grooves in the sidewalls of the base. The kay shaped projections and the key shaped grooves may be formed as a dovetail connection. These key blocks provide support for the sidewalls from forces resulting from relatively high overcurrent conditions, such as a short circuit condition. In addition to supporting the sidewalls, the key blocks also form a barrier between the main contacts and other components in the circuit breaker to reduce the amount of arc products allowed to interact with the other components in the circuit breaker. The key block also form a stop surface for capturing the arc chutes to prevent movement of the arc chutes along the longitudinal axis of the circuit breaker. Lastly, the key blocks also hold the insulation barrier on the line conductor in place, thus obviating the need to use adhesives.