Classification of Explosion Proof Lighting

There is often a misunderstanding from customers that ask for an explosion proof lighting.  We ask them if that is what they need because many times they only need a hazardous location or Class 1 Division 2.   The differences in the fixtures are considerable as well as the price.  Please see the below information on the difference of a Class 1 Division 1 light and a Class 1 Div 2 light.

Hazardous Location Types

Class I Locations

According to the NEC, there are three types of hazardous locations. The first type of hazard is one which is created by the presence of flammable gases or vapors in the air, such as natural gas or gasoline vapor. When these materials are found in the atmosphere, a potential for explosion exists, which could be ignited if an electrical or another source of ignition is present. The Code writers have referred to this first type of hazard as Class I explosion proof led lighting .

So, a Class I Hazardous Location is one in which flammable gases or vapors may be present in the air in sufficient quantities to be explosive or ignitable. Some typical Class I locations are:

Petroleum refineries, and gasoline storage and dispensing areas;

Dry cleaning plants where vapors from cleaning fluids can be present;

Spray finishing areas;

Aircraft hangars and fuel servicing areas; and

Utility gas plants, and operations involving storage and handling of liquefied petroleum gas or natural gas.

All of these are Class I . . . gas or vapor . . . hazardous locations. All require special Class I hazardous location equipment.

Class II Locations

The second type of hazard listed by the National Electrical Code are those areas made hazardous by the presence of combustible dust. These are referred to in the Code as “Class II Locations.” The finely pulverized material, suspended in the atmosphere, can cause as powerful an explosion as one occurring at a petroleum refinery. Some typical Class II locations are:

Grain elevators;

Flour and feed mills;

Plants that manufacture, use or store magnesium or aluminum powders;

Producers of plastics, medicines, and fireworks;

Producers of starch or candies;

Spice-grinding plants, sugar plants and cocoa plants; and

Coal preparation plants and other carbon handling or processing areas.

Class III Locations

Class III hazardous locations, according to the NEC, are areas where there are easily-ignitable fibers or flyings present, due to the types of materials being handled, stored, or processed. The fibers and flyings are not likely to be suspended in the air,but can collect around machinery or on lighting fixtures and where heat, a spark or hot metal can ignite them. Some typical Class III locations are:

Textile mills, cotton gins;

Cottonseed mills, flax processing plants; and

Plants that shape, pulverize or cut wood and create sawdust or flyings.

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