UL 1203

Please note: All interim revisions for this edition available at time of your purchase will be included.

Explosion-Proof and Dust-Ignition-Proof Electrical Equipment for Use in Hazardous (Classified) Locations
UL 1203
1 Scope
1.1 These requirements cover explosion-proof and dust-ignition-proof electrical 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.

1.2 These requirements also cover explosion-proof electrical equipment for installation and use in Class I, Zone 1, Groups IIA, IIB, and IIC hazardous (classified) locations and dust-ignition-proof equipment for use in Zone 20, 21, and 22 locations.

1.3 These requirements also cover explosion-proof electrical equipment that has been investigated for use in one or more specific gas or vapor atmospheres with or without additional Class I Groups. See 60.6.

1.4 These requirements do not cover equipment for use in hazardous (classified) locations specifically covered in a separate standard.

1.5 These requirements do not cover electrostatic devices, circuits or systems; refrigeration system controllers or the internal construction of electrical instruments such as meters.

1.6 These requirements cover equipment for use under the following atmospheric conditions:

• A minimum ambient temperature of minus 50°C (minus 58°F);
• An oxygen concentration not greater than 21 percent by volume; and
• A nominal barometric pressure of one atmosphere.

1.7 Equipment covered by this standard shall also comply with the applicable requirements for similar equipment for use in ordinary unclassified locations.