ARTICLE 501. CLASS I LOCATIONS


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ARTICLE 501. CLASS I LOCATIONS
ARTICLE 501. CLASS I LOCATIONS501.1. Scope. In any Class I location, an explosive mixture of air and flammable gas or vapor may be present, which can be caused to explode by an arc or spark. To avoid the danger of explosions, all electrical apparatus that may create arcs or sparks should, if possible, be kept out of the rooms where the hazardous atmosphere exists, or, if this is not possible, such apparatus must be "of types approved for use in explosive atmospheres."All equipment such as switches, CBs, or motors must have some movable operating part projecting through the enclosing case, and any such part—for example, the operating lever of a switch or the shaft of a motor—must have sufficient clearance so that it will work…
Citation
Frederic P. Hartwell; Joseph F. McPartland; Brian J. McPartland: McGraw-Hill's National Electrical Code 2017 Handbook, 29th Edition. ARTICLE 501. CLASS I LOCATIONS, Chapter (McGraw-Hill Professional, 2017), AccessEngineering Export