NEMA Definitions – Waterproof/Industrial Computers

NEMA 1 General Purpose – Indoors:   Primarily to prevent accidental contact of personnel with the enclosed equipment, in areas where unusual service conditions do not exist. Protection against limited amount of falling dirt. Shall prevent the insertion of the end portion of a straight rod of specified diameter into the equipment into the equipment cavity.   Shall not rust when subjected to a salt spray test for 24 hours.
NEMA 2 Drip Proof – Indoors:   Protect equipment against falling non-corrosive liquids and falling dirt.
NEMA 3 Dust Tight, Rain Tight, and Sleet – Resistant – Outdoors: Protect Equipment against wind-blown dust and water, external ice formation.
NEMA 4 Water Tight and Dust Tight – Indoors and Outdoors: Protect equipment against splashing water, seepage of water falling or hose directed water and severe external condensation.
NEMA 4X Water Tight, Dust Tight, and Corrosion Resistant – Indoors and Outdoors: Protect equipment against splashing water, seepage of water falling or hose directed water and severe external condensation. In addition enclosures are corrosion resistant.
NEMA 5 Indoors: Similar to Type 1 Protection against dust.
NEMA 6 Indoors and Outdoors:   Protection against the entry of water during occasional temporary submersion at a limited depth.
NEMA 7 Indoors: Designed to contain an internal explosion without causing an external hazard.
NEMA 8 Indoors and Outdoors:   Enclosures have all arcing contacts, connections, etc., immersed in oil so that arcing will not ignite and explosive gas mixture in internal spaces. External surfaces cannot reach temperatures capable of igniting explosive gas-air mixtures in surrounding atmosphere.
NEMA 9 Indoors: Prevent entrance of combustible dust.   Shall not cause external surface to reach temperatures cable igniting or discoloring dust on enclosure.
NEMA 10 Indoors: Enclosures shall meet requirements of the Mine Safety and Health Administration, Part 18.
NEMA 11 Indoors: Primarily to provide by oil immersion protection to enclosed equipment against corrosive effects of liquids and gases.
NEMA 12 Dust Tight and Drip Tight – Industrial – Indoors: Protection against fibers, flyings, lint, dust, and dirt, and non-corrosive liquids.
NEMA 13 Oil Tight and Dust Tight – Indoors: Protection against lint and dust, seepage, external condensation spraying of water, oil, or coolant, for switches, pushbuttons, pilot lights, etc., housed in enclosure.

Hazardous Definitions – Rugged Hazardous Computers

CLASSIFICATION TYPICAL MATERIALS
CLASS I GASSES
Those areas in which flammable gases or vapors may be present in the air in sufficient quantities to be explosive or ignitable.
GROUP A
GROUP B
GROUP C
GROUP D
CLASS II DUST
Those areas made hazardous by the presence of combustible dusts.
GROUP E
GROUP F
GROUP G
CLASS III FLYINGS
Those areas in which there are easily ignitable fibers or flyings present due to the type of material being handled, stored, or processed. These may include rayon, cotton, sisal, hemp, jute, spanish moss, and similar substances.
DIVISION 1A location in which ignitable concentrations of the combustible material(s) are present in the air under normal operating conditions. DIVISION 2A location in which ignitable concentrations of the combustible material(s) are present in the air only under abnormal operating conditions, such as the case during accidental rupture or breakage, or during unusual or faulty