SHIELD APPARATUS FOR CIRCUIT BREAKER

摘要

An improved circuit breaker having an improved shield apparatus provides protection to components that are internal to the circuit breaker during an arc event. A contact arm carrier assembly of the circuit breaker comprises a number of springs that bias a number of movable contacts that are disposed on contact arms into engagement and electrical connection with a stationary contact. The shield apparatus is disposed on a carrier housing of the contact arm carrier assembly and is situated adjacent the springs. A shield member of the shield apparatus is biased into engagement with the contact arms. When the circuit breaker is moved between the ON position and the OFF or TRIPPED positions, the shield of the shield apparatus moves between a retracted position and a deployed position, with the shield remaining in engagement with the contact arms and protecting the springs from damage in an arc event. In one embodiment, the shield member is formed of a material that generates gases when struck by an arc.