Hazardous Locations Classification

In North America, hazardous locations have traditionally been defined by a combination of classes and divisions as follows:

Hazardous Location Classes

• Class I – A location made hazardous by flammable gases or vapours that may be present in the air in quantities sufficient to produce an explosive or ignitable mixture.
• Class II – A location made hazardous by the presence of combustible or electrically conductive dust
• Class III – A location made hazardous by the presence of easily ignitable fibres or flyings in the air but not likely to be in suspension in quantities sufficient to produce ignitable mixtures

Hazardous Location Divisions

• Division 1 – A location where a classified hazard exists or is likely to exist under normal conditions
• Division 2 – A location where a classified hazard does not normally exist but is possible to appear under abnormal conditions

North American Transition to the Zone System

The U.S. and Canada have recently revised installation codes to recognize an international 3-Zone area classification system for equipment used in hazardous locations.

• Zone 0 – An area in which an explosive gas atmosphere is continuously present for a long period of time
• Zone 1 – An area in which an explosive atmosphere is likely to occur in normal operation
• Zone 2 – An area in which an explosive gas atmosphere does not normally exist.

In Canada, all new installations must use the 3-Zone system. Existing installations may continue to use the 2-Division system or opt to re-classify using the 3-Zone system.

In the U.S., all installations (both new and existing) can either continue using the 2-Division system or re-classify their product using the 3-Zone system.

Selecting Motors for Hazardous Locations

When selecting a motor for hazardous locations, there are specific criteria to consider, including the T code and motor ratings. Review our blog article on selecting a motor for hazardous locations for more specifics.

Explore our selection of Explosion-Proof Motors.