Electrical enclosures are made to protect us from the potential electrical hazards inside, and protect the interior components from outside environmental conditions.
The National Electrical Manufacturers Association, or NEMA, defines standards used in North America for different grades of electrical enclosures. They provide ratings, referred to as “types”, that allow users to determine whether an enclosure is right for their needs.
This NEMA Enclosure Ratings Chart shows the list.
Enclosures, usually made from rigid plastics, steel, stainless steel, or aluminum, provide, according to NEMA, a degree of protection to personnel against access to hazardous parts, and a degree of protection to the equipment inside the enclosure against ingress of solid foreign objects (falling dirt).
All NEMA rated enclosures follow NEMA standards to ensure that control panels, VFDs, and breaker boxes meet the required criteria. This chart compares the more commonly used enclosure types.