These requirements cover industrial control equipment for installation and use in hazardous (classified) locations, Class I, Division 1, Groups A, B, C, and D, and Class II, Division 1, Groups E, F, and G, 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.
Examples of industrial control equipment are:
a) Manual and magnetic starters and controllers.
b) Thermal- and magnetic-overload relays.
c) Pushbutton stations, including selector switches and pilot lights.
d) Control-circuit switches and relays.
e) Float-, flow-, pressure-, and vacuum-operated switches.
f) Resistors and rheostats.
g) Proximity switches.
h) Time-delay relays and switches.
i) Resistors and rheostats intended for industrial heating and lighting, including those for motorgenerator fields.
j) Control devices intended for industrial heating and lighting.
k) Variable-voltage autotransformers.
These requirements apply to industrial control equipment for use in hazardous locations under the following atmospheric conditions:
a) A minimum ambient temperature of minus 25°C (minus 13°F),
b) An oxygen concentration not greater than 21 percent by volume, and
c) A nominal barometric pressure of one atmosphere.
These requirements do not cover intrinsically-safe electrical circuits of industrial control equipment for use in hazardous locations.
These requirements do not cover electrostatic devices, circuits, or systems.
These requirements do not cover refrigeration-system controllers or the internal construction of electrical instruments such as meters.
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 the appropriate additional component and end-product requirements as determined necessary to maintain the acceptable 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 cannot be judged to comply with this standard. Where considered appropriate, revision of requirements shall be proposed and adopted in conformance with the methods employed for development, revision, and implementation of this standard.