National Electrical Manufacturers Association standards that classify enclosures by the level of protection they provide against environmental conditions such as dust, water, and corrosion
NEMA 3: Enclosure rating for protection against rain, sleet, snow, and windblown dust, suitable for outdoor use in standard weather conditions
NEMA 4: Enclosure rating for watertight and dust-tight protection against splashing or hose-directed water, falling dirt, and windblown dust, suitable for indoor or outdoor use
NEMA 4X: Enclosure rating with all the protections of NEMA 4 plus added corrosion resistance, making it ideal for marine, chemical processing, and wastewater environments
NEMA 12: Enclosure rating for indoor use, protecting against dust, dirt, fibers, dripping water, and non-corrosive liquids, commonly used in industrial and manufacturing facilities
