US Patent 10326259 Isolation and exhaust system for an electrical enclosure

An electrical enclosure, such as a Motor Control Centers (MCC), can include a ventilation system providing airflow while protecting from both ingress of solid objects as small as 1.0 millimeter and egress of gasses from an arc flash by providing a protective mesh with holes having a dimension of less than 1 millimeter, a bracket coupled to the mesh for providing a rigid support, and a flap configured to seal against the bracket and block the mesh in response to a pressure wave produced by an arc flash. The flap, normally open for airflow, can close in response to the pressure wave, by bending at a perforation line to move the flap toward the mesh. The electrical enclosure can also include a normally closed exhaust system. The exhaust system can be configured to open in response to the pressure wave to allow the gasses to escape.