Explosion-proof motors are designed to handle hazardous conditions and reduce the risk of fire or explosion. But not all explosion-proof electric motors can handle flammable matter in the same capacity, and just because a motor operates in a hazardous location doesn’t mean it is also explosion-proof. In this blog post, we will discuss what types of explosion proof motors exist, how they work, and why you may need them for your next project!
Knowing the division, class, and group of your property is crucial for ensuring you choose a well-suited motor that will improve productivity without introducing the danger of explosions.
Likewise, fully understanding the hazardous location and explosion-proof motor standards will greatly reduce the risk of accidents and injuries.
More cautious users may also explore the auto-ignition temperatures of their flammables and put in place cooling systems or ventilation machines, which keep heating in check and
prevent the buildup of incendiary material in enclosed spaces.
Thankfully, there are many explosion-proof motors that can handle sensitive environments and applications without posing a risk of fire or secondary explosions.
*Introduction to Explosion Proof Motors:
Division: Location of motor
- Division I — A Division I location is hazardous even in normal conditions. Flammable particulate matter or incendiary liquids are produced, and they accumulate as a result of the execution of manufacturing processes.
- Division II — A Division II location becomes hazardous in abnormal conditions. If there is a rupture, burst, or leak resulting in spillage or seepage of inflammable substances, then the area is considered a Division II property.
Class: Location of motor
- Class I — Class I locations contain gases and vapors that are known to auto-ignite and cause explosions. Gasoline and acetylene are common examples of such vapors.
- Class II — Class II locations involve the presence of flammable dust, like grain and coal, in the environment.
- Class III — Class III locations involve the presence of flammable fibers, such as textile and wood shavings.
Groups: Type of Principal Flammable Agent
- Groups A to D — Acetylene, hydrogen, ethylene, and acetone are some of the gases and vapors that belong to these groups.
- Groups E to G — Covering aluminum, coal, corn, and sugar, these groups only pertain to flammable particulate matter.
Classifications and Standards for Hazardous Location Motors: A Five-Step Selection Guide
Choosing the right hazardous location motor can be challenging, especially if you don’t know much about motors. But using this list of guidelines can help users find a type that suits their needs.
- Figure out what type of property your location has. (The different types are Residential, Commercial, or Hazardous)
- If you need an explosion-proof electric motor for a Division I, Class I location, it should be able to withstand exposure to flammable vapors. Tight joints and flame paths help stifle escaping flames so they can be extinguished.
- Division I, Class II electric motors have special casing and bearing dust seals to keep the surface cool.
- When you are purchasing an electric motor, it is more important to review the class of your location, as opposed to the division. By default, all Division I equipment will also serve Division II requirements. Motors that serve Division II locations are generally called hazardous location motors — motors that can handle unusual hazardous circumstances.
- UL is the only agency recognized by safety agencies to approve motors in hazardous locations. However, UL does not offer any evaluation standards for:
- Motors that can run in Division I, Class I, Groups A and B locations
- Motors that run in Division II locations
- Motors that run in Class III locations