UL Standard for Safety Electrical Equipment for Use in Class I and II, Division 2, and Class III Hazardous (Classified) Locations Third Edition;Reprinted With Revisions Through and Including 2/3/2004
1.1 These requirements apply to equipment, circuits, or components intended for use in Class I, Groups A, B, C, and D, Division 2, hazardous (classified) locations; Class II, Groups F and G, Division 2, hazardous (classified) locations; and Class III, Divisions 1 and 2, hazardous (classified) locations as defined in Article 500 of the National Electrical Code, NFPA 70. 1.2 The equipment shall be capable of being installed in accordance with the requirements in the National Electrical Code, NFPA 70.Battery-powered portable equipment need not comply with this requirement 1.3 The requirements cover Class I, Division 2 electrical equipment, or parts of such equipment, in which the circuits and components under intended operating conditions are incapable of causing ignition of the specified flammable gas- or vapor-air mixture. 1.4 These requirements cover Class II, Division 2, and Class III, Division 1 and Division 2 equipment that is constructed to reduce or exclude the entrance of dust. 1.5 These requirements apply only to equipment for use under the following atmospheric conditions.a)An ambient temperature of 5 to 40℃ (41 to 104℉),b)An oxygen concentration not greater than 21 percent, and c)A nominal barometric pressure of one atmosphere.1.6 These requirements cover portable battery-powered equipment, other than flashlights and lanterns, for Class I and Class II, Division 2, and Class III, Divisions 1 and 2 hazardous (classified) locations. 1.6.1 These requirements also cover equipment, circuits, or components intended for installation and use in Class I, Zone 2, Groups IIA, IIB, and IIC hazardous (classified) locations. 1.7 These requirements do not cover electric lighting fixtures for use in Division 2 hazardous (classified) locations which are covered in the Standard for Electric Lighting Fixtures for Use in Hazardous (Classified) Locations, UL 844. 1.8 These requirements do not cover electric motors, electric heaters, heat tracing cables and similar heat-producing devices, or equipment with cathode ray tubes, for use in Division 2 locations. Such products are covered under separate requirements. 1.9 These requirements do not cover explosion-proof, dust-ignition-proof, or intrinsically-safe methods of protection for electrical equipment or parts thereof. Such methods of protection are considered acceptable for Division 2 hazardous locations. The requirements are covered in other standards. 1.10 A product that contains features, characteristics, components, materials, or systems new or different from those covered by the requirements in this standard, and that involves a risk of fire or of electric shock or injury to persons shall be evaluated using appropriate additional component and end-product requirements to maintain the level of safety as originally anticipated by the intent of this standard. A product whose features, characteristics, components, materials, or systems conflict with specific requirements or provisions of this standard does not comply with this standard. Revision of requirements shall be proposed and adopted in conformance with the methods employed for development, revision, and implementation of this standard.