Defining Class 1 Specifications and Subgroups

Defining Class I Specifications and Subgroups
Class I is part of the National Electric Code definitions of hazardous location classifications and protection techniques. The Class I classification is a segment of the basic designation which is listed by ''class'' and ''division.''

Class I locations are areas where flammable gases may be present in sufficient quantities to produce explosive or flammable mixtures. Class II locations can be described as hazardous because of the presence of combustible dust. Class III locations contain easily ignitable fibers and flyings. Division 1 designates an environment where flammable gases, vapors, liquids, combustible dusts or ignitable fibers and flyings are likely to exist under normal operating conditions. On the other hand, Division 2 is an environment where flammable gases, vapors, liquids, combustible dusts or ignitable fibers and flyings are not likely to exist under normal operating conditions. Hazardous atmospheres are further defined by ''groups.'' These include:

  • Group A: Atmospheres containing acetylene.
  • Group B: Atmospheres containing hydrogen, gases or vapors of equivalent hazard such as manufactured gas.
  • Group C: Atmospheres containing ethyl-ether vapors, ethylene, or cyclo-propane.
  • Group D: Atmospheres containing gasoline, hexane, naptha, benzene, butane, propane, alcohol, acetone, benzol, lacquer solvent vapors, or natural gas.
  • Group E: Atmospheres containing metal dust - including aluminum, magnesium, and their commercial alloys, and other metals of similarly hazardous characteristics.
  • Group F: Atmospheres containing carbon black, coal or coke dust.
  • Group G: Atmospheres containing flour, starch, or grain dusts.

Class I, Division 2 Products -- hazardous area flat panel computers -- feature full agency approvals and are available with 12.1", 15", and 17" displays. Sunlight-readable displays available in 15" systems.

Wolverine: A sunlight readable, industrial PC is HAZLOC approved and ruggedized for use in virtually any environment. It sports a NEMA 4 environmentally sealed enclosure with corrosion resistance. The Wolverine now includes a heater option to allow operational temperature ranges down to -40° C.