Understanding the NEC Hazardous Location Option: Class I, Div 2, Groups A, B, C, and D, for Enclosure Cooling Systems


When you are working with hazardous materials, it is important to know exactly how the materials and compounds are classified. It can also be incredibly valuable to have equipment that will withstand any harsh conditions, as well as not promote any dangerous situations. With enclosure cooling systems designed for NEC Hazardous Locations, you can be confident that your facility will remain safe and your equipment function as designed.

The NEC Hazardous Location Option, Defined

Class I Hazardous Locations refer to facilities which deal with flammable gases, vapors, and liquids. Division 2 specifies that these flammable materials are handled, processed, or used in the defined hazardous location, but not normally present in concentrations high enough to be ignitable. Simply put, this requires proper handling and storage of the flammable substances to prevent ignition under normal operating conditions. This also might involve a positive mechanical ventilation system that prevents any ignitable concentration from forming. Absent any breakdown of the ventilation equipment, the concentration of the flammable gases or liquid-produced vapors will never reach an ignitable level.

Division 2 has 4 groups within it containing different levels of flammability and combustibility of the gases, liquids, or vapors.

  • Group A contains only acetylene.

  • Group B includes hydrogen, gases with more than 30% hydrogen by volume, butadiene, ethylene oxide and propylene oxide.

  • Group C includes acetaldehyde, cyclopropane, diethyl ether, and dimethyl hydrazine.

  • Group D includes gasoline, acetone, ammonia, benzene, butane, methane, propane, alcohols and other more commonly encountered compounds.

What the NEC Hazardous Location Options Mean for your Enclosure Cooling Systems

When searching for an enclosure cooling system, having an air conditioner that will be operate safely in a NEC Hazardous Location is essential. While just meeting the requirements to for safe operation is imperative, having an enclosure cooling system that can operate efficiently and adjust to changing demands at your plant will help keep your mind at ease.

Exact attention needs to be paid to the designations for each specific group. An enclosure air conditioner may operate safely within a Class I Hazardous Location with Division 2, Group D designation, but be unsafe for use in a Group B location.

If you would like more information on enclosure air conditioners that fit your specific needs, including enclosure cooling systems that are designed for all requirements to operate in Class I, Division 2, Groups A, B, C, and D NEC Hazardous Locations, contact the sales team at Thermal Edge today.