NEMA Enclosure Ratings

Without strict standards to hold companies reliable, consumers of metal enclosures would have a difficult time deciding which product best fit their needs. The technical standards and guidelines developed by the National Electrical Manufacturers Association (NEMA) are used to grade enclosures for industrial applications. The NEMA enclosure ratings are based on the enclosure’s level of protection against personal access to hazardous parts as well as the product’s defense against environmental hazards. Consider where your enclosure will be located and the elements it will be up against before deciding which enclosure best fits your needs.

NEMA Enclosure Ratings

There are many NEMA enclosure ratings, but today we’re focusing on seven of the most popular: 1, 2, 3, 3-R, 3-X, 4, and 4-X. To view all of the ratings, visit the NEMA website.

TYPE 1: A type 1 NEMA enclosure rating denotes a general-purpose product for indoor use. Although it protects against dust, light, and indirect splashing, it is not dust-tight. Type 1 enclosures are used indoors under normal conditions and prevent contact with live parts.

TYPE 2: A type 2 NEMA enclosure rating signifies that the enclosure is meant for indoor use and provides an additional level of protection to personnel against hazardous parts. It protects against the entrance of solid foreign objects (like falling dirt) as well as some water (dripping and light splashing only). It is drip-tight and so can be used in rooms with higher levels of condensation.

TYPE 3: A type 3 NEMA enclosure is weather resistant, which means it can be used outdoors. It protects against falling dirt, windblown dust, rain, sleet, and snow, and it won’t be damaged by the exterior formation of ice. Due to these attributes, type 3 enclosures can be used on ship docks, construction sites, tunnels, subways, and more.

TYPE 3-R: A type 3-R NEMA enclosure is identical to a type 3 enclosure, except it does not protect against windblown dust.

TYPE 3-X: A type 3-X NEMA enclosure is also identical to a type 3 enclosure, but it protects against corrosion as well. For this reason, 3-R enclosures are often used near salt water.

TYPE 4: A type 4 NEMA enclosure is watertight. In addition to preventing the ingress of solid foreign objects (falling dirt, windblown dust), it must protect the equipment from water. This includes rain, sleet, and snow as well as splashed water and water directed at the enclosure with a hose. Plus, the enclosure should be undamaged by the external formation of ice. You can find type 4 enclosures on ship docks and in dairies and breweries.

TYPE 4-X: A type 4-X NEMA enclosure is identical to a type 4 enclosure, but it provides additional corrosion resistance.

As we mentioned above, these are just a few of the types of enclosure available. The other NEMA enclosure ratings (5, 6, 6P, 7, 8, 9, 10, 12, 12K, and 13) apply to enclosures that offer additional protection. For example, type 6 enclosures can be submersed in water or oil, type 10 enclosures meet the requirements of the Mine Safety and Health Administration (MSHA), and type 11 enclosures meet drip and corrosion-resistance tests.

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Using the NEMA enclosure ratings, you can select an enclosure that suits your specific application and goals.

If you’re on the hunt for a company that can manufacture premium metal enclosures on your behalf, check out American Products Contract Manufacturing. Our high-quality, innovative enclosures enable our customers to assist the telecommunications industry in expanding and improving their network services. We offer NEMA type 1, type 2, type 3, type 3-R, type 3-X, type 4, and type 4-X metal enclosures, and we form these enclosures from aluminum, galvanized steel, carbon steel, and stainless steel to create a rugged and reliable structure. Give us a call at 1-877-736-2228 to learn more, or request a free quote online.