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NEMA ratings can often be confusing. All too often, enclosures are specified with the wrong NEMA rating, which can mean wasted revenue if the chosen rating is too high, or premature failure and the potential for safety risks if the rating is too low. Choosing the correct enclosure for your needs helps reduce costs and ensures that your components are adequately defended.
Who is NEMA?
The National Electrical Manufacturers Association (NEMA) is an organization developed to form the standards for the manufacturing of industrial electrical enclosures in North America.
What do NEMA ratings mean?
Enclosures are given a NEMA rating according to the types of applications the enclosure serves. Each rating is assigned to describe protection against environmental hazards such as water, dust, oil, or hazardous areas that contain corrosive or explosive climates.
What are the different NEMA classifications?
Below is a list of the different NEMA panel classifications, which will aid you in choosing the correct panel for your application. (Note: enclosures designated with an “X” indicates a corrosion-resistant rating and are constructed from a corrosive- resistant material).
- NEMA 1 enclosures are constructed for indoor use and provide protection against human contact with live electrical components. They also protect the equipment from falling debris, such as dirt and dust.
- NEMA 2 enclosures are offer the same benefits as NEMA 1 enclosures. However, a NEMA 2 rating provides additional protection from light dripping or splashing of water (drip-proof).
- NEMA 3R and 3RX enclosures are engineered for both indoor and outdoor use and protect against rain, sleet, snow, dirt. Additionally, they are built to prevent ice formation.
- NEMA 3 and 3X enclosures are rain-tight, sleet-tight, and dust-tight. Made for both indoor and outdoor use, NEMA 3 and 3X enclosures also provide added protection against dust beyond the NEMA 3R or 3RX enclosures.
- NEMA 3S and NEMA 3SX enclosures provide similar protection as a NEMA 3. However, these enclosures will remain operable when covered in ice.
- NEMA 4 and NEMA 4X enclosures are intended for both indoor and outdoor use. They provide the same protections as a NEMA 3 enclosure, with additional protection against water intrusion or hose-directed water. Therefore, if a NEMA 4 enclosure needs to be cleaned with a water hose, there is no need to worry about water damaging the electrical components within.
- NEMA 6 and NEMA 6P enclosures provide the same protection as a NEMA 4 enclosure. In addition, these enclosures are capable of protecting the electrical components in temporary or prolonged water submersion up to a designated depth.
- NEMA 7 enclosures are built for indoor use in hazardous locations. These enclosures are explosion proof.
- NEMA 8 enclosures offer the same protection as a NEMA 7 enclosure, but this type of enclosure can be used in both indoor and outdoor hazardous locations.
- NEMA 9 enclosures are dust ignition proof and intended for indoor use in hazardous locations.
- NEMA 10 enclosures are designed to meet MSHA (Mine Safety and Health Administration) standards.
- NEMA 12 and NEMA 12K enclosures are intended for general purpose or indoor use. These enclosures protect against dripping and splashing water, are rust resistant, and do not include knockouts (partially punched openings easily removed to accommodate cables, connectors, and/or conduits).
- NEMA 13 enclosures are for indoor use with a general purpose. They provide the same protection as the NEMA 12 enclosures, but with better protection against dripping and/or sprayed oils and coolants.
A quality enclosure in a manufacturing environment not only maintains a better appearance over time, it also does a better job protecting the electrical components that it houses. Choosing the right enclosure depends on the environment, location, features and materials. Paying close attention to the enclosure selected is the key to a successful application.