NEMA Type Enclosures
Type 1. General Purpose: For general purpose applications indoors and where atmospheric conditions are normal, designed to prevent accidental contact with current carrying parts of the equipment. A Type 1 enclosure serves as a protection against dust and light, undirected splashing, but is not dust-tight.
Type 2. Drip Tight: Similar to general purpose type, with shields added to protect against dripping. Construction as to exclude falling moisture or dirt. A Type 2 enclosure is suitable for application where condensation may be severe such as is encountered in cooling rooms or laundries.
Type 3. Weather Resistant: For use where exposed to rain or sleet and on docks, canal locks and in subways or tunnels.
Type 4. Watertight: For use outdoors or where equipment might be subjected to splashing, dripping or hose directed stream of water. A Type 4 enclosure is suitable for application outdoors on ship docks and in dairies, breweries, etc.
Type 5. Dust-Tight: Prevents entry of dusts into controllers used in such non-hazardous areas as cement mills, steel mills and coke plants, where dust or lint would interfere with the operation of the controller.
Type 6. Submersible: For use where the unit might be submerged in water, as in mines, quarries and manholes.
Type 7. Hazardous Locations: For use in Class I, Groups A, B, C or D hazardous locations containing gases. Divisions I and II are included.
Type 8. Hazardous Locations: Similar to Type 7 except that the contacts are immersed in oil. Intended for use for hazardous gases are corrosive.
Type 9. Hazardous Dust-Tight: For use in Class II, Groups E, F or G hazardous locations such as flour mills, grain elevators or textile mills.
Type 10. Bureau of Mines: For use in coal mines. This enclosure is designed to meet the explosion-proof requirements of the U.S. Bureau of Mines. It is suitable for use in gaseous mines.
Type 12. Industrial Use: Enclosures designed for use in automotive and other industrial plants, to protect equipment against dirt and oil by preventing seepage of infiltration and keeping lint fibers and flyings out of the controller. This type of enclosure has found wide application as a substitute for Type 1 enclosures and is mandatory in the JIC Electrical Standards for Industrial Equipment.