Get Guide To Hazardous Locations

The need for Explosion-Proof equipment then arises due to this potential for fire or explosion. ... Division 1 is a subset of Class I and is classified as an area where the explosive or flammable gases, vapors or liquids mentioned above can exist under normal, everyday operating conditions.

Hazardous locations are categorized by class, group, and division as follows. Class I: Denotes areas where flammable gas, vapor, or liquid is present. Class II: Denotes areas where combustible dust is present. Class III: Denotes areas where ignitable fibers are present.

Class I, Division 2 or Zone 2 classified locations. An area where ignitable concentrations of flammable gases, vapors or liquids are not likely to exist under normal operating conditions. In this area the gas, vapor or liquids would only be present under abnormal conditions (most often leaks under abnormal conditions).

The National Electrical Code (NEC) defines hazardous locations as those areas "where fire or explosion hazards may exist due to flammable gases or vapors, flammable liquids, combustible dust, or ignitable fibers or flyings." A substantial part of the NEC is devoted to the discussion of hazardous locations.

Class I locations are those in which flammable vapors and gases may be present. Class II locations are those in which combustible dust may be found. Class III locations are those which are hazardous because of the presence of easily ignitable fibers or flyings.

Class II Locations The second type of hazardous location is called a Class II Location . This classification is created by the presence of combustible dust in the air in sufficient quantities to be explosive or ignitable.

The need for Explosion-Proof equipment then arises due to this potential for fire or explosion. ... Division 2 is also a subset of Class I and is classified as an area where the explosive or flammable gases, vapors or liquids mentioned above are not likely to exist during regular operation.

Class I, Division 2 or Zone 2 classified locations. An area where ignitable concentrations of flammable gases, vapors or liquids are not likely to exist under normal operating conditions. In this area the gas, vapor or liquids would only be present under abnormal conditions (most often leaks under abnormal conditions).