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UL Standard for Safety for Electric Heaters For Use in Hazardous (Classified) Locations,

UL 823

Scope

These requirements cover portable and fixed electric heaters for installation and use in hazardous (classified) locations, Class I, Divisions 1 and 2, Groups A, B, C, and D; Class II, Division 1, Groups E, F, and G; Class II, Division 2, Groups F and G; and Class III, Divisions 1 and 2 in accordance with the National Electrical Code, NFPA 70.

These requirements also cover explosion-proof electrical equipment for installation and use in Class I, Zone 1, Groups IIA, IIB, IIB plus Hydrogen, and IIC hazardous (classified) locations.

These requirements cover electric air heaters, electric hot-water or steam radiators, and electric hot plates rated 600 volts or less.

These requirements also cover paint heaters, rated 600 volts or less, for use at pressures not exceeding 100 psig (690 kPa). Paint heaters operating at more than 100 psig may be investigated in accordance with these requirements and any additional requirements judged to be necessary.

These requirements do not cover medical equipment.

These requirements cover heaters for use only under the following atmospheric conditions:

A minimum ambient temperature of minus 25 C (minus 13 F),

An oxygen concentration not greater than 21 percent by volume, and

A nominal barometric pressure of one atmosphere.

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, electric shock, or injury to persons shall be evaluated using appropriate additional component and end-product requirements to maintain the 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.