For many years, major losses, injuries, and fatalities all over the world were caused by unexplained industrial explosions. A lot of research went into the causes of these explosions. Explosion-proof motors
were developed to comply with safety standards that resulted from the research findings.Faulty or unqualified motors generate excess heat that can ignite flammable or explosive materials. The National Fire Protection
Association (NFPA) in the USA defined a universal way to categorize hazardous environments in Classes, Groups, and Divisions. This system is used to approve equipment that can be used in each category.When buying explosion-proof motors, make sure they meet the standards defined for your application. The main NFPA classification of hazardous environments is set in three classes as follows.- Class I refer to environments with exposure to ignitable or explosive liquids and gases such as in petroleum refineries.- Class II refers to environments with high concentrations of electrically conductive metallic and non-metallic dust such as in flour and feed mills.- Class III refers to environments with ignitable fibers and materials such as textiles, flax, and sawdust. Depending on the concentration of material, you may not need explosion-proof motors in these settings.