Understanding Arc Flash Hazards in Commercial Facilities
Arc flash is one of the most dangerous events a commercial electrical worker can face. It is also one of the most misunderstood by building owners. Here is what property managers and facility directors across the Lowcountry need to know.
What arc flash actually is
An arc flash is a rapid release of energy caused by an electrical fault jumping between conductors or between a conductor and ground. Peak temperatures inside an arc exceed 35,000 degrees Fahrenheit, hotter than the surface of the sun. The blast expands violently and can send molten metal, superheated air, and pressure waves through a room in milliseconds.
Why it matters even in a small building
Arc flash energy scales with available fault current and the time the upstream protective device takes to clear. Even a 200A commercial service can produce incident energy above the safe working threshold. NFPA 70E requires that anyone working live on the equipment know that number and dress accordingly.
How the risk is quantified
A licensed engineering firm produces an arc-flash study by modeling the utility source, service equipment, feeders, and protective devices. The output is an incident energy value at each work location, expressed in calories per square centimeter, plus a boundary distance and required PPE category. Labels are then affixed to every panel and disconnect.
What building owners actually have to do
- Commission a study when major equipment is installed or replaced
- Refresh the study every three to five years, or after any significant electrical modification
- Apply the resulting labels to every piece of gear
- Verify that any contractor who works energized on your equipment has the required PPE and training
How to reduce arc flash exposure
- Design for de-energized work whenever possible
- Coordinate protective devices so upstream breakers clear the fault as fast as possible
- Add arc energy reduction technology such as maintenance switches on main breakers
- Keep equipment maintained so the study results remain valid
EmergenServe installs to arc-flash-compliant standards, applies labels from your study, and partners with specialty engineering firms when a study is required. Call (843) 754-1671 to scope arc-flash mitigation for your facility.