SEISMIC Enclosure Accessories

NEMA 3R, 4, 4X

Electrical enclosures are cabinets that are designed to house electrical components. Their main function is to protect the components, as well as to protect the operators from electrical hazards. Enclosures are typically made of solid plastics, fiberglass and metal materials, such as carbon steel, stainless steel and aluminum.

One of the most important things to consider when selecting an electrical enclosure is the NEMA rating. NEMA stands for National Electrical Manufacturer Association. They have developed a rating system which determines the types of environments an electrical enclosure can be used in. 

NEMA 3R enclosures. The NEMA definition of a 3R enclosure is as follows: ‘Enclosures constructed for either indoor or outdoor use to provide a degree of protection to personnel against access to hazardous parts, to provide a degree of protection of the equipment inside the enclosure against Ingress of solid foreign objects such as falling dirt, to provide a degree of protection with respect to harmful effects on the equipment due to the Ingress of water, rain, sleet or snow, and that will be undamaged by the external formation of ice on the enclosure.’ NEMA 3R enclosures provide adequate outdoor protection while providing significant cost savings over NEMA 4 and NEMA 4X enclosures. 

NEMA 4 enclosures. They provide all of the same protections found in the NEMA 3R enclosures with two additional protection elements, protection against wind-blown dust particles and protection against hose directed water. NEMA 4 enclosures provide this additional protection using a gasket material to prevent water or dust from entering the enclosure,
while the NEMA 3R enclosures rely on enclosure design and gravity to assist in diverting water and dust.
 

NEMA 4X enclosures. They provide all of the same protections found in the NEMA 4 enclosures with one added protection element, corrosion resistance. NEMA 4X enclosures are typically made of either stainless steel or fiberglass.