NEMA Ratings – What they mean for Industrial Enclosures

At ITSENCLOSURES, most of our industrial, heavy-duty enclosures are rated NEMA 12, NEMA 4, and NEMA 4X. Our NEMA-rated enclosures are ideal for any and all environments where dust, dirt and exposure to liquids or corrosives threaten the performance of your equipment.

NEMA standards/ratings were established by the National Electrical Manufacturer’s Association and detail minimum enclosure construction, performance, test criteria, and corrosion resistance.
When discussing enclosure standard types, two main categories exist: indoor and indoor/outdoor. The numbers do not always correspond to the level of protection. For example, NEMA 4X offers more protection than a NEMA 12 cabinet enclosure.
According to the official NEMA Rating Documentation, here are the three main ratings for enclosures which are fabricated by ITSENCLOSURES (more detailed explanation below):

NEMA 12

Protects against dust, dirt, and splashing fluids

 

NEMA 4

Protects against hose directed water and corrosive materials

 

NEMA 4X (Stainless)

Protects against dust, dirt, and hose directed fluids and corrosive materials

 

NEMA 12: Enclosures 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 of the equipment inside the enclosure against ingress of solid foreign objects (falling dirt and circulating dust, lint, fibers, and flyings); and to provide a degree of protection with respect to harmful effects on the equipment due to the ingress of water (dripping and light splashing).

NEMA 4: 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 (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.

Type 4X: 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 (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 level of protection against corrosion; and that will be undamaged by the external formation of ice on the enclosure.

Use this flowchart to determine what NEMA rating to choose.

nema flowchart

Source: https://www.nema.org/Products/Documents/nema-enclosure-types.pdf