Arc Flash Study
An Arc Flash Study is a formal engineering evaluation of a facility's electrical distribution system that calculates incident energy (cal/cm²) and defines safe approach boundaries to determine required arc-rated PPE and safe work practices for energized equipment.
On the shop floor, the study results drive equipment labeling showing incident energy and PPE category, guide maintenance procedures in the CMMS, and ensure workers wear the correct PPE before opening panels. It requires data collection, single-line diagram verification, power system modeling using tools like ETAP, and incident energy calculations per IEEE 1584.
- Invalidated studies due to unrecorded electrical system changes such as new transformers or altered breaker settings without updating the model, leading to under-rated PPE and severe worker injury.
- Outdated assessments failing the NFPA 70E mandatory 5-year review, resulting in non-compliance penalties, fines, and liability after an incident.
- Poor data collection such as incorrect conductor lengths or missing utility fault current data causing incorrect incident energy calculations, leading to equipment damage during maintenance or worker burns.
What standard governs the calculation methodology?
IEEE 1584-2018 is the primary method for 208V–15kV three-phase AC systems; NFPA 70E mandates the risk assessment framework.
When must a study be updated immediately (not just every 5 years)?
Immediate updates are required after significant electrical system changes such as new feeders, utility source changes, or protective device re-settings.
Who is qualified to perform the study?
Only a qualified Professional Engineer (PE) with expertise in power systems should perform it to ensure technical accuracy and legal defensibility.