NEMA enclosure types
NEMA defines standards for various grades of electrical enclosures typically used in industrial applications. Each is rated to protect against designated environmental conditions. A typical NEMA enclosure might be rated to provide protection against environmental hazards such as water, dust, oil or coolant or atmospheres containing corrosive agents such as acetylene or gasoline. A full list of NEMA enclosure types is available from the NEMA website.[1]
Enclosure types
Below is a list of NEMA enclosure types; these types are further defined in NEMA ICS 6: Enclosures standard.
NFPA is National Fire Protection Association, and NEC is National Electrical Code (U.S.A.)
| NEMA Type | Definition |
|---|---|
| 1 | General-purpose. Protects against dust, light, and indirect splashing but is not dust-tight; primarily prevents contact with live parts; used indoors and under normal atmospheric conditions. |
| 2 | Drip-tight. Similar to Type 1 but with addition of drip shields; used where condensation may be severe (as in cooling and laundry rooms). |
| 3, 3S, 3X | Weather-resistant. Protects against weather hazards such as rain and sleet; used outdoors on ship docks, in construction work, and in tunnels and subways. X (as 3X) indicates additional corrosion resistance. |
| 3R | Intended for outdoor use. Provides a degree of protection against falling rain and ice formation. Meets rod entry, rain, external icing, and rust-resistance design tests. |
| 4 and 4X | Watertight. Must exclude at least 65 GPM of water from 1-in. nozzle delivered from a distance not less than 10 ft for 5 min. Used outdoors on ship docks, in dairies, and in breweries. X (as 4X) indicates additional corrosion resistance. |
| 5 | Dust-tight. Provided with gaskets or equivalent to exclude dust; used in steel mills and cement plants. |
| 6 and 6P | Submersible. Design depends on specified conditions of pressure and time; submersible in water or oil; used in quarries, mines, and manholes. |
| 7 | Certified and labeled for use in areas with specific hazardous conditions: for indoor use in Class I, Groups A, B, C, and D environments as defined in NFPA standards such as the NEC. |
| 8 | Certified and labeled for use in areas with specific hazardous conditions: for indoor and outdoor use in locations classified as Class I, Groups A, B, C, and D as defined in NFPA standards such as the NEC. |
| 9 | Certified and labeled for use in areas with specific hazardous conditions: for indoor and outdoor use in locations classified as Class II, Groups E, F, or G as defined in NFPA standards such as the NEC. |
| 10 | MSHA. Meets the requirements of the Mine Safety and Health Administration, 30 CFR Part 18 (1978). |
| 11 | General-purpose. Protects against the corrosive effects of liquids and gases. Meets drip and corrosion-resistance tests. |
| 12 and 12K | General-purpose. Intended for indoor use, provides some protection against dust, falling dirt, and dripping noncorrosive liquids. Meets drip, dust, and rust resistance tests. |
| 13 | General-purpose. Primarily used to provide protection against dust, spraying of water and noncorrosive coolants. Meets oil exclusion and rust resistance design tests. |
NEMA enclosure ratings are similar to IEC IP Codes and can offer the same protections,[3] but cannot directly be mapped. See IP Codes & NEMA.
See also
References
- ^ http://www.nema.org/prod/be/enclosures/upload/NEMA_Enclosure_Types.pdf
- ^ "NEMA/IEC enclosure ratings", Cole-Parmer Technical Library
- ^ http://www.bisonprofab.com/ip-ratings-explained.htm | Bison Profab's IP Ratings Calculator Comparison