Print Page   |   Contact Us   |   Sign In   |   Join
IAEI Magazine | Author: Edward M. Briesch
Share |

Edward M. Briesch

Ed Briesch is a senior staff engineer with Underwriters Laboratories and has been involved with Hazardous Locations equipment and installations for over 30 years. He is a principle member of NEC CMP-14 and the NFPA Technical Committee on Electrical Equipment in Chemical Atmospheres. He is also a member of several IEC, ASTM, IEEE and ISA technical committees related to explosion protected equipment. Ed has a BSChE from the Illinois Institute of Technology and is a Registered Professional Engineer in the State of Illinois.


Understanding the Zone Area Classification Method in the NEC

The division classification method has been used in the United States since being incorporated into NEC 1920 to cover electrical and electronic equipment and wiring in extra-hazardous areas where fire or explosion hazards may exist from flammable and combustible liquids, vapors, or gases. The use of the term extra-hazardous locations implied that an electrical installation was already a hazardous installation but where used in areas, rooms, or compartments with some chemicals, it was more hazardous than usual. In NEC 1931, the term classifications was added to the NEC along with Class I, Class II, and III. The term extra-hazardous has been dropped from the NEC. These areas are now called hazardous (classified) locations which differentiates the hazardous chemical areas with electrical equipment from hazardous health areas.