Arc-resistant switchgear enclosure with arcing chamber venting structure

Abstract

An improved arc-resistant switchgear enclosure is disclosed. The disclosed arc-resistant switchgear enclosure provides a cost effective structure to collect and channel the pressure and hot exhaust gases from lower compartments and safely vent these gases through the switchgear enclosure. In preferred embodiments, an internal arc chamber is formed by assembling modules and creating a void within the center of the switchgear enclosure. As multiple compartments or modules for a switchgear enclosure are connected, an arc chamber is created within the enclosure. Upon initiation of an arc fault within a particular compartment, a relief flap or cover for that particular compartment opens to channel the pressure and the gases into the internal arc chamber or directly through the top of the enclosure. Pressure and gases are vented into the internal arc chamber and flow horizontally through the arc chamber until a path to the top of the switchgear enclosure is reached. These, pressures and hot gases are then channeled upward and safely out of the switchgear enclosure. Also disclosed is a ventilation system for an arc-resistant switchgear enclosure that provides natural ventilation while preventing any arc gases from entering the lower, ventilated compartment(s), and that permits proper venting of pressure arc gases if originated in the ventilated compartment(s).