NEMA Ratings

The National Electrical Manufacturers Association (NEMA) is a US Manufacturers Organization which actively promotes standardized product specifications for electrical apparatus. While NEMA does not actually test products, it establishes the performance criteria for enclosures intended for specific environments.

NEMA standards describe each type of enclosure in general and functional terms, and specifically omits reference to construction details. In other words, NEMA specifies what an enclosure must do, not how to manufacture it.

NEMA performance criteria and test methods are used by Underwriters Laboratories (UL) and the Canadian Standards Association (CSA) as guidelines for investigation and listing of electrical enclosures. The tested enclosures are then authorized to carry a label by UL or CSA to prove it has passed the required tests and meets the applicable UL and CSA standard.

STRONGARM designs and manufactures enclosures per the following NEMA standards:

NEMA 4

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 (falling dirt and windblown dust); to provide a degree of protection with respect to harmful effects on the equipment due to the ingress of water (rain, sleet, snow, splashing water, and hose directed water); and that will be undamaged by the external formation of ice on the enclosure.

NEMA 4X

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 (windblown dust); to provide a degree of protection with respect to harmful effects on the equipment due to the ingress of water (rain, sleet, snow, splashing water, and hose directed water); that provides an additional degree of protection against corrosion and that will be undamaged by the external formation of ice on the enclosure.

NEMA 12

Constructed without knockouts for indoor use to provide a degree of protection to personnel against access to hazardous parts; to provide a degree of protection from the equipment inside the enclosure against ingress of solid foreign objects (falling dirt, circulating dust, lint, fiber and flying’s); and to provide a degree of protection with respect to harmful effects on the equipment due to ingress of water (dripping and light splashing).

Material courtesy of National Electrical Manufacturers Association

For a complete list of the NEMA standards please click here.