Understanding NEMA ratings for industrial electrical enclosures is crucial to ensure your equipment is reliably protected and within regulation.
NEMA Certification Explained
The National Electrical Manufacturer Association (NEMA) lays out a detailed rating system for industrial enclosures based on the type of equipment, the use case, and the operational environment.
The NEMA rating system thus defines different grades of electrical enclosures, each rated with different levels of protection against environmental conditions (e.g. indoor vs. outdoor use; weather-resistant vs. weatherproof) as well as protection against personnel access.
Below, we’ve laid out a quick guide to the different grades and types of industrial electrical enclosures, with brief descriptions of each rating.
Guide to NEMA Types:
NEMA 1 Enclosures – Designed for indoor use, NEMA 1 enclosures are rated for limited protection against falling dirt, dust and other debris, but are primarily used to prevent human contact with electrical components.
NEMA 2 Enclosures – Also designed for indoor use, very similar to NEMA 1 enclosures but with the addition of drip shields for enhanced water drip protection in key areas. Enclosures for industrial cooling systems would be a common example where drip shields are required.
NEMA 3 Enclosures – Designed for outdoor use, weather-resistant electrical enclosures offering a level of protection against rain, sleet, falling dirt, windblown dust, and external ice formation. Common enclosures for outdoor industrial use, construction work, tunnel systems, etc.
NEMA 3R Enclosures – The same as standard NEMA 3 enclosures without the specific protection against windblown dust, e.g. for indoor operational environments in which dust is not an issue.
NEMA 3S Enclosures – The same as standard NEMA 3 enclosures but designed to allow operation of external mechanisms when the enclosure is coated with ice.
NEMA 3X Enclosures (3X, 3RX, 3SX) – The same as the above NEMA 3 enclosures with the addition of enhanced corrosion protection, common for enclosures subjected to salt water spray.
NEMA 4 Enclosures – Watertight electrical enclosures designed for indoor or outdoor use, rated to withstand water sprayed at 65 GPM out of a 1” nozzle from 10 ft away or less for a 5-minute duration.
NEMA 4X Enclosures – The same as NEMA 4 enclosures with the addition of enhanced corrosion protection.
NEMA 5 Enclosures – Dust-tight electrical enclosures for indoor use, commonly installed in steel mills, concrete plants, and other manufacturing factories.
NEMA 6 Enclosures – Designed for indoor or outdoor use, NEMA 6 enclosures offer temporary protection against submersion in water.
NEMA 6P Enclosures – Offering protection against prolonged submersion compared to standard NEMA 6 electrical enclosures.
NEMA 7 Enclosures – Explosion-proof electrical enclosures designed for indoor use. NEMA 7 enclosures are rated for use in applications defined by the National Electric Code (NFPA 70) as Class I, Division 1, Groups A, B, C, and D hazardous locations.
NEMA 8 Enclosures – Indoor or outdoor use in locations classified as Class I, Division 2, Groups A, B, C or D hazardous locations as defined in the National Electric Code (NFPA 70) (commonly referred to as oil-immersed).
NEMA 9 Enclosures – Designed for indoor use to meet specific requirements for hazardous locations, NEMA 9 electrical enclosures are rated for use in applications defined by the National Electric Code (NFPA 70) as Class II, Division 1, Groups E, F and G.
NEMA 10 Enclosures – Electrical enclosures designed for hazardous locations specific to the mining industry, NEMA 10 enclosures are rated to satisfy the requirements of Mine Safety and Health Administration (MSHA) 30 CFR Part 18 (1978).
NEMA 11 Enclosures – Designed for indoor use, NEMA 11 are general-purpose electrical enclosures that offer corrosion protection against many common liquids and gasses.
NEMA 12 Enclosures – Designed for indoor use and rated for general protection against falling dirt, dust, and dripping non-corrosive liquids.
NEMA 12K Enclosures – The same as standard NEMA 12 enclosures with the addition of pre-constructed knockouts designed to accommodate the integration of cables, wiring, antennas, and other electrical components.
NEMA 13 Enclosures – Designed for indoor use to provide protection against falling dirt, dust, water spray, oil, and various non-corrosive liquids common in industrial applications.
DMG’s Certifications as an Industrial Enclosure Manufacturer:
- ISO 9001:2015
- Certified Manufacturer of Electrical Enclosures
- UL508A Control Panel Fabricator
- NEMA 1, 3, 3R, 4, 4X, and 12
Quality Industrial Sheet Metal Enclosures – Made in the USA
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