The Class 1 Division 1 (or it’s roman numeral equivalent Class i Division 1) classification defines a specific hazardous location in which ignitible flammable gases or vapors exist:
- Under normal operating conditions.
- Because of repair, maintenance or leakage.
- Breakdown or faulty operation of equipment which causes them to become a source of ignition. In other words, under ordinary circumstances, ignitable flammable gas or vapors exist in this space.
HVAC equipment built for Hazardous or classified environments have come to be known as Explosion Proof That does not mean these air conditioners are bombproof; instead, an explosion proof air conditioner is one that was built or modified so it does not become an ignition source through arch or spark in a hazardous location where gases, dust or fibers are or may be present in combustible concentrations.
It’s the responsibility of those who understand the dangers of the
products and manufacturing environments, such as the fire marshal, plant facility engineer, or insurance underwriter, to identify the classification of a hazardous area. Many items that are generally regarded as harmless such as grains, metals, and dusts become a fire or explosion hazard when particles are less than 500 microns and dispersed in the air.