Class II Locations
Class II Locations The second type of hazard listed by the National Electrical Code is those areas made hazardous by the presence of combustible dust.
What is a Class 3 hazardous location?
Class III locations consist of locations where fibers and flyings may exist that have the potential to become flammable or ignitable. Locations that would be considered to be Class III include Cotton Gins, Cotton Seed Mills, Sawdust or flyings plants, or Textile mills.
What is a Class 1 hazardous location?
Class I Locations A “Class I Location” is created by the presence of flammable gases or vapors in the air in sufficient quantities to be explosive or ignitable. When these materials are found in the atmosphere, a potential for explosion exists if an electrical or other source of ignition is present.
What is an example of combustible dust?
Examples include: agricultural products such as egg whites, powdered milk, cornstarch, sugar, flour, grain, potato, rice, etc. metals such as aluminum, bronze, magnesium, zinc, etc. chemical dusts such as coal, sulphur, etc.
What is a Class III Division 2 location?
Class Definition Class II locations are those in which combustible dust may be found. Class III locations are those which are hazardous because of the presence of easily ignitable fibers or flyings.
How many classes of hazards are there?
nine classes
A visor card guide for state and local law enforcement officials illustrating vehicle placarding and signage for the following nine classes of hazardous materials: 1) Explosives, 2) Gases, 3) Flammable Liquid and Combustible Liquid, 4) Flammable Solid, Spontanaeously Combustible and Dangerous When Wet 5) Oxidizer and …
What are the 5 elements of combustible dust explosion?
The Five Elements Of Combustible Dust Explosions
- Combustible Dust.
- Distribution Of Dust Particles.
- Confined Dust Cloud.
- Oxygen.
- Ignition Source.
What are examples of dust?
Examples of the types of dust found in the work environment include:
- mineral dusts, such as those containing free crystalline silica (e.g., as quartz), coal and cement dusts;
- metallic dusts, such as lead, cadmium, nickel, and beryllium dusts;
- other chemical dusts, e.g., many bulk chemicals and pesticides:
What is hazardous area classification?
Zone 1: An area in which an explosive gas atmosphere is likely to occur in normal operation; Zone 2: An area in which an explosive gas atmosphere is not likely to occur in normal operation and, if it occurs, will only exist for a short time.
What are examples of combustible dust?
What are examples of materials that can be a combustible dust hazard?
- agricultural products such as egg whites, powdered milk, cornstarch, sugar, flour, grain, potato, rice, etc.
- metals such as aluminum, bronze, magnesium, zinc, etc.
- chemical dusts such as coal, sulphur, etc.
- pharmaceuticals.
- pesticides.
- rubber.
- wood.
What makes an area hazardous because of combustible dust?
Locations that are hazardous because of the presence of combustible dust. Note that the dust must be present in sufficient quantities for a fire or explosion hazard to exist. The fact that there is some combustible dust present does not mean a Class II hazardous location exists.
What are the requirements for a Class II hazardous area?
Note that the dust must be present in sufficient quantities for a fire or explosion hazard to exist. The fact that there is some combustible dust present does not mean a Class II hazardous location exists. To be considered a “dust”, the combustible material must exist as a finely divided solid of 420 microns (0.420 mm) or less.
How are Class 2 combustible metal dusts classified?
Class II combustible dusts are grouped into one of three (3) groups: E combustible metal dusts, F combustible carbonaceous dusts or G other combustible dusts. The Zone Classification System is offered as an alternative to the Class and Division system.
How are flammable gases classified in hazardous areas?
Class I flammable gases and vapors are grouped into one of four groups (Groups A, B, C or D) based on their physical properties and the ease in which they can be ignited. Class II combustible dusts are grouped into one of three (3) groups: E combustible metal dusts, F combustible carbonaceous dusts or G other combustible dusts.
