Explosion Proof Panels may be installed in Class I, II or III Hazardous Locations according to appropriate National Electrical Code (NEC) installation practices. These control panels can consist of a NEMA 7 explosion proof enclosure or a general purpose enclosure with purging / pressurization features.
NEMA 7 enclosures are heavy duty enclosures designed to withstand and contain an internal explosion without igniting flammable vapors that may be present outside of the panel.
Purged panels include a standard NEMA 4 or 4X enclosure with a nitrogen or air purge system that maintains a constant positive pressure within the enclosure so that no flammable vapors may enter the enclosure. These systems can be equipped with extra safety features such as a pressure switch that will remove power from the panel if the pressure within the enclosure falls under a set point. Purged panels are a much more cost effective option for explosion proof applications.