NEMA Outdoor Enclosure Ratings-Type 3R,4,4X

Apr 23 , 2021

"What is a NEMA rated enclosure?" is a frequently asked question, in this article we will introduce the NEMA rating

The National Electrical Manufacturers Association (NEMA) is an industrial organization representing electrical equipment and medical imaging manufacturers that sets the standards for the environments in which electrical enclosures can be used. NEMA ratings range from Type 1 (i.e., NEMA 1) Type 13 (i.e., NEMA 13), each of which indicates varying levels of protection against environmental conditions and contaminants. For example, NEMA 4X enclosures are suitable for use in indoor or outdoor environments, where they protect against dust, rain, sleet, snow, water, and ice.

The NEMA standard on outdoor enclosures and cabinets provides general information on the definitions of NEMA Enclosure Types to architects, engineers, installers, inspectors and other interested parties. AZE manufactures outdoor enclosures and cabinets to meet both NEMA 3 and NEMA 3R ratings. Although the NEMA standard supports a range of NEMA ratings from 1 through 12, most enclosures for wireline, wireless, and energy applications require NEMA 3 or NEMA 3R ratings. Most general industrial applications will require NEMA 3 or NEMA 4 variants. A summary of the most relevant NEMA ratings for outdoor industrial enclosures and cabinets is listed below.

Type 3

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); and that will be undamaged by the external formation of ice on the enclosure.

Type 3R

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); to provide a degree of protection with respect to harmful effects on the equipment due to the ingress of water (rain, sleet, snow); and that will be undamaged by the external formation of ice on the enclosure. Relative to the NEMA 3 standard, this style of enclosure does not have a gasketed sealing surface. So, it subsequently excludes protection against windblown dust and allows the ingress of external air into the enclosure. Most enclosures or cabinets that house wireless, wireline, or energy electronics specify a NEMA 3R enclosure.

Type 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. NEMA 4 enclosures are typically used in many applications where; an occasional wash-down occurs, a machine tool cutter coolant is used, or a pressurized stream of water is used. NEMA 4 enclosures are gasketed and the door is clamped for maximum sealing from outside air penetration. They have continuous hinges, mounting feet, and padlock hasps.

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. NEMA 4X enclosures are used in more corrosive environments than standard NEMA 4 units. Applications where corrosive materials and caustic cleaners are used necessitate the use of a NEMA 4X enclosure. Applications include food/meat/poultry processing facilities, where total wash-down with disinfectants occur repeatedly, and petro-chemical facilities. NEMA 4X is used when protection from the worst environments is required.

NEMA 4 vs. NEMA 4X

NEMA ratings sometimes come with several subsets. For example, there are three NEMA 3 ratings—NEMA 3, NEMA 3RX, and NEMA 3SX. Generally, the variations provide additional protection on top of the existing protection of the base rating.

Between NEMA 4 and NEMA 4X, the main difference is the addition of corrosion resistance. While both ratings indicate some degree of protection against wind, rain, dirt, dust, sleet, snow, hose water, lint, and external ice formation, only NEMA 4X offers protection against corrosion. For this reason, NEMA 4X enclosures are generally fabricated from corrosion-resistant materials such as aluminum or stainless steel.

NEMA ratings are derived from these standards. A wide range of industry professionals—including engineers, contractors, and inspectors—use them to understand whether an enclosure is suited for use in a particular environment.

So now, we know: NEMA is a rating system for equipment that might be exposed to liquids, rain, ice, corrosion and contaminates such as dust. ... Protects against dust, light, and indirect splashing but is not dust-tight. Primarily prevents incidental contact with the enclosure equipment.

Custom your NEMA 4, NEMA 4X rated outdoor enclosures, AZE can make IT happen.

Looking for more range of outdoor weatherproof enclosures?

Outdoor Server Cabinet    Wall Mount Outdoor Cabinet      Outdoor Telecom Enclosure    Outdoor Battery Enclosure 

From data center to outdoor telecom infrastructure products, AZE has the right product for you. AZE designs and manufactures Server Racks and Enclosures, Outdoor Telecom Cabinets and Electronic Enclosures, Power Distribution (Basic Rack PDUs and Smart PDUs), KVM Switches and Fiber optics products to globe customers in the market.

Make IT Connected, AZE can support you to make IT happen with affordable cost.

Contact AZE  to customize your steel outdoor enclosures.

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