Honeywell ST 3000 Installation Manual page 94

B.1 North American Classification of Hazardous
Locations,
Examples
Groups
84
Continued
Given the above criteria, the following examples are made:
• A Class III, Division 1 location is a location in which easily
ignitable fibers or material processing combustible flyings are
handled, manufactured or used.
• A Class III, Division 2 location is a location in which easily
ignitable fibers are stored or handled.
Flammable gases, vapors and ignitable dusts, fibers and flyings are
classified into one of the following groups according to the energy
required to ignite the most easily-ignitable mixture within air.
Class I
Group
A Atmospheres containing acetylene.
B Atmospheres containing hydrogen, fuel and combustible
process gases containing more than 30 percent hydrogen by
volume, or gases or vapors of equivalent hazard
C Atmospheres such as ethyl ether, ethylene, or gasses or vapors
of equivalent hazard.
D Atmospheres such as acetone, ammonia, benzene, butane,
cyclopropane, ethanol, gasoline, hexane, methanol, methane,
natural gas, naphtha, propane or gases or vapors of equivalent
hazard.
Class II
Group
E Atmospheres containing combustible metal dusts including
aluminum, magnesium, and their commercial alloys, and other
metals of similarly hazardous characteristics.
F Atmospheres containing combustible carbonaceous dusts
including carbon black, charcoal, coal or other dusts that have
been sensitized by other materials so that they present an
explosion hazard.
G Atmospheres containing combustible dusts not included in
Group E or F, including flour wood, grain, and other dusts of
similarly hazardous characteristics.
ST 3000 Release 300 Installation Guide
Description of Atmosphere
Description
2/05