There are two primary motor types that we use on Americraft fans, TEFC (Totally Enclosed Fan Cooled) and hazardous location explosion proof motors.    The motor selection is based on the environment in which the fan will operate.  Are there hazardous gases, vapors or dust in the air as a result of your manufacturing process?  If so, you may need to consider purchasing a motor suitable for hazardous locations.

The Class/Division/Group system below is intended to give you broad understanding of hazardous area classifications.  This information is not intended to recommend a specific hazardous duty motor, but to provide you with enough information to ask the right questions when selecting a motor for your fan.   

CAUTION:  Only the end user or a qualified underwriter is to identify and select the proper class, division, group and temperature code motor to meet your requirements.


Identifies the physical characteristics of the hazardous materials present where the motor will be operating.

  • CLASS IGases, Vapors and Liquids that are “explosive” or “ignitable”.
  • CLASS IIDusts that are present in amounts sufficient to create explosive mixtures.
  • CLASS IIIFibers that are “ignitable”.  CLASS III locations do not typically require hazardous location motors.


Identifies the probability of the hazardous material being able to “explode” or “ignite.”

  • DIVISION I – Indicates the hazardous material has a high probability of producing an explosive or ignitable mixture because it is present at some level under normal operating conditions
  • DIVISION II – Indicates the hazardous material has a low probability of producing an explosive or ignitable mixture because it is present only under abnormal conditions for a short period of time.


A group rating is assigned to “explosive” or “ignitable” substances based on the outcome after ignition.  Group ratings start with “A” through “G” and are rated in descending order according to the stringency of the motor design requirements.

ClassGroupAtmospheres Containing:
B (MESC is < .45mm)Flammable Gas, Vapor (e.g., hydrogen, butadiene, ethylene oxide, propylene oxide, acrolein.)
C (MESG is > .45mm)Flammable Gas, Vapor (e.g., ethyl either, ethylene, acetaldehyde, cyclopropane.)
D (MESE is > .75mm)Flammable Gas, Vapor (e.g., acetone, ammonia, benzene, butane, ethanol, gasoline, methane, natural gas, naphtha, propane.)
IIEMetal Dusts (e.g., aluminum, magnesium and their commercial alloys.)
FCarbonaceous Dusts (e.g., carbon black, coal, coke dust.)
GDusts NOT included in Groups E or F (e.g., flour, starch, grain, wood, plastic, chemicals.)
IIINo groups assignedFibers – Typically do not require hazardous location motors.

Once you have an idea of the type of environment in which your fan will operate, contact us and we can discuss your needs further to make sure you have considered all possibilities before buying a fan with a hazardous duty explosion proof motor.