What are NEMA Enclosure Ratings?

The National Electrical Manufacturer Association (NEMA) publishes electrical and medical imaging standards and technical whitepapers for much of North America. NEMA believes that standards play an important role in the “design, production, and distribution of products destined for both national and international commerce.” NEMA standardizes electrical equipment to help consumers choose from safe, effective, and compatible electrical products.

What do NEMA enclosure ratings mean?

NEMA provides standards and ratings for a wide variety of electrical supplies. Their enclosure ratings differ from their contact ratings and connector configuration types.

NEMA enclosure ratings, sometimes referred to as NEMA types, define the type of environment electrical enclosures can work in and signify the ability of an enclosure to withstand specified environmental conditions. NEMA enclosure types range from Type 1 to Type 13 with each offering varying degrees of protection. However, they do not necessarily go in ascending order. For example, a Type 4 offers stronger protections than a Type 12. Additionally, not every enclosure type works outdoors.

NEMA Type	Description
1	Indoor use only Provides a degree of protection against the ingress of solid foreign objects (falling dirt) Protects against incidental contact with enclosure equipment
2	Indoor use only Provide a degree of protection against falling dirt and limited amounts of falling water such as dripping and light splashing such as condensation
3	Indoor or outdoor use Provides a degree of protection against rain, sleet, falling dirt, and windblown dust Remains undamaged by external formation of ice
3R	Indoor or outdoor use Provides a degree of protection against rain, sleet, and falling dirt Remains undamaged by external ice formation Includes a small drainage hole to prevent liquid accumulation
3X, 3RX, 3SX	X indicates additional corrosion resistance Commonly used near salt water
4	Indoor or outdoor use Provides a degree of protection against rain, sleet, snow, falling dirt, wind-blown dust, splashing water, and hose-directed water Remains undamaged by external ice formation
4X	Same protections as Type 4 and adds corrosion resistance
5	Indoor use only Provides a degree of protection against solid foreign objects such as settling airborne dust, falling dirt, lint, flyings, and fibers Provides protection against light splashing or dripping water Provided with gaskets or equivalent to keep out dust
6	Indoor or outdoor use Provides a degree of protection against hose-directed water, damage from external ice formation, and the entry of water during temporary submersion at a low depth
6P	Same protections as Type 6 plus corrosion resistance and prolonged submersion at a low depth
7	Indoor use only Can contain an internal explosion without causing an external hazard Suitable for locations in Class I, Division 1, Groups A, B, C, or D according to the NFPA 70 National Electrical Code
8	Indoor and outdoor use Equipment immersed in oil to prevent combustion Suitable for locations classified as Class I, Division 1, Groups A, B, C, or D according to the NFPA 70 National Electrical Code
9	Indoor use only Prevents the ignition of combustible dust Suitable for locations classified as Class II, Division 1, Groups E to G according to the NFPA 70 National Electrical Code
10	Meets the requirements for the Mine Safety and Health Administration (MSHA) Capable of containing an internal explosion
11	Indoor use only Provides a degree of protection against falling dirt, dripping water, and light splashes Drip-proof Provides protection of enclosed equipment against the corrosive effects of fumes and gases Oil-immersed
12	Indoor use only Constructed without knockouts Provides a degree of protection against falling dirt, circulating dust, and dripping non-corrosive liquid Does not include knock-out holes
12K	Same protection as Type 12 Includes knock-out holes
13	Indoor use only Protects against incidental contact with enclosed equipment Provide a degree of protection against dust and the spraying of water and non-corrosive oil and coolant

What is the difference between NEMA ratings and IP ratings?

IP stands for ingress protection and indicates an electrical product’s ability to protect against the ingress of water and substances such as dirt and dust. IP ratings are an international standard that sets a guideline for electrical devices. They indicate how waterproof or dustproof an electrical device is.

NEMA ratings include protection standards against corrosion resistance and distinctions between hazardous and non-hazardous environments. NEMA ratings can also indicate protection against physical damage.

Avery Dietzen

Originally from Wisconsin, Avery earned her degree in English before making the trip down to the Atlanta, GA area. Writer by day, reader by night, she prides herself on having a creative outlook and tries to instill that in everything she writes. As a content writer for HomElectrical, she uses her skills to share tips and tricks about lighting, HVAC, and going green. If she’s not writing, she’s reading, painting, hanging out with her dog, or spending time with family and friends.

What are NEMA Enclosure Ratings?

What do NEMA enclosure ratings mean?

What is the difference between NEMA ratings and IP ratings?

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