Classifications Meeting The Nec 500; Divisions; Explosion Protection Groups - WAGO 750 Series Manual

224 • Use in Hazardous Environments

Classifications Meeting the NEC 500

Further Information
For more detailed information please refer to the national and/or international
standards, directives and regulations!
11.4 Classifications Meeting the NEC 500
The following classifications according to NEC 500 (National Electric Code)
are valid for North America.

11.4.1 Divisions

The "Divisions" describe the degree of probability of whatever type of
dangerous situation occurring. Here the following assignments apply:
Explosion endangered areas due to combustible gases, fumes, mist and dust:
Division 1
Division 2

11.4.2 Explosion Protection Groups

Electrical components for explosion endangered areas are subdivided in three
danger categories:
Class I (gases and fumes):
Class II (dust):
Class III (fibers):
Encompasses areas in which explosive atmospheres are to be expected
occasionally (> 10 h ≤ 1000 h /year) as well as continuously and long-term
(> 1000 h /year).
Encompasses areas in which explosive atmospheres can be expected rarely
and short-term (>0 h ≤ 10 h /year).
Group A (Acetylene)
Group B (Hydrogen)
Group C (Ethylene)
Group D (Methane)
Group E (Metal dust)
Group F (Coal dust)
Group G (Flour, starch and cereal dust)
No sub-groups
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