What is an arc flash boundary?

Arc flashes are dangerous events that can impact an entire facility. They are most dangerous, however, for those who are in the immediate vicinity of where the fault occurs. Anyone in the area is going to be exposed to extremely high temperatures, which can cause serious burns very quickly. Of course, anyone who comes into contact with the arc flash will also experience electrocution, which can be deadly.

To help keep those who work around electrical equipment safe, facilities need to set arc flash boundaries. These boundaries will let employees and others in the area know where the most serious danger is so they can avoid it whenever possible.

What is the Arc Flash Boundary?

Many people mistake an arc flash boundary for being the distance from an electrical system that an arc flash, or its heat, can cause injury to a person. This is actually not the case. Arc flash boundaries are calculated to be the distance from the equipment until the point where the energy from the arc flash would be 1.2 cal/cm2. This energy level is sufficient to cause second-degree burns, but not third degree.

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While nobody wants to get any type of burn, second-degree burns are very treatable. Third-degree burns are much more serious, can leave extensive scarring, and cause long term disabilities. Having an arc flash boundary at this level allows people to work in the area with the understanding that if they cross the line, the danger goes up significantly.

Benefits of Arc Flash Boundaries

The most obvious benefit of an arc flash boundary is, as mentioned above, that people will know where the most serious risks exist. This will also let them know where they should begin wearing different levels of personal protection equipment. Even outside the arc flash boundary it is a good idea to at least wear basic PPE to avoid any type of injury. By wearing proper PPE on either side of the boundary, those in the area can properly respond to an emergency, which will help to keep the facility safe.

Marking the Arc Flash Boundary

Once the arc flash boundary has been identified, facilities should make it clear so that those working or visiting the area will be able to spot it. This is typically done with floor marking tape as well as wall signs or labels. Alerting people to the presence of the boundary will allow them to take proper precautions and help contribute to the overall safety of the entire facility.


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