| Quick answer: An IEEE 1584 incident energy analysis calculates the arc flash energy — in calories per square centimeter (cal/cm²) — that a worker could be exposed to at each point in an electrical system. A qualified engineer collects system data (equipment, conductors, protective-device settings, and available fault current), builds a power-system model, runs short-circuit and protective-device coordination studies, then applies the IEEE 1584-2018 equations to determine incident energy, the arc flash boundary, and the required PPE at every location. The results are documented and applied as warning labels. |
What is IEEE 1584?
IEEE 1584, the IEEE Guide for Performing Arc-Flash Hazard Calculations, is the internationally recognized method for calculating arc flash incident energy. The current edition, IEEE 1584-2018, is based on thousands of laboratory tests and applies to systems from 208 V to 15 kV. It provides the equations engineers use to predict arcing current, incident energy, and arc flash boundaries. NFPA 70E requires an incident energy analysis but points to IEEE 1584 as the calculation method.
What data do you need for an IEEE 1584 study?
An accurate analysis depends on accurate inputs. A study typically requires:
- An up-to-date single-line diagram of the electrical distribution system
- Utility available fault current, or transformer and source impedance data
- Equipment types and enclosure dimensions
- Conductor sizes, types, and lengths
- Protective device makes, models, and settings
- Working distances for each class of equipment
Missing or estimated data is the most common reason results come out wrong — which is why field verification matters.
How do you perform an IEEE 1584 incident energy analysis?
The process follows eight core steps:
- Collect field data. Inventory the equipment, gather nameplate data, and confirm protective-device settings on site.
- Obtain available fault current from the utility for the service entrance.
- Build the power-system model in analysis software, based on the single-line diagram.
- Run a short-circuit study to determine the bolted fault current at each bus.
- Perform a protective-device coordination study. This establishes how quickly each device clears a fault — arcing duration is the single biggest driver of incident energy.
- Apply the IEEE 1584-2018 equations to calculate arcing current, incident energy (cal/cm²), and the arc flash boundary at each location.
- Determine PPE requirements based on the calculated incident energy at each point.
- Generate and apply equipment labels, then document the full study.
What does an IEEE 1584 analysis produce?
The deliverables are the incident energy (cal/cm²) at each equipment location, the arc flash boundary (the distance at which incident energy drops to 1.2 cal/cm²), the required arc-rated PPE, and standardized warning labels for every piece of equipment. Together, these tell a worker exactly how to approach and work on that equipment safely.
How is IEEE 1584 different from NFPA 70E?
They work together but do different jobs. IEEE 1584 is the calculation method — the math that produces the incident-energy numbers. NFPA 70E is the safety standard — it requires the risk assessment, sets the rules for PPE and approach boundaries, governs safe work practices, and mandates that the study be reviewed at least every five years. In short: IEEE 1584 tells you the hazard level; NFPA 70E tells you what to do about it.
Who can perform an IEEE 1584 arc flash analysis?
An IEEE 1584 incident energy analysis should be performed by a qualified engineer — ideally a licensed Professional Engineer (PE) experienced in power-system studies — because it requires short-circuit and coordination modeling, not just data entry. Bowtie Engineering performs IEEE 1584-based incident energy studies led by licensed PEs, and pairs them with NFPA 70E training so your team can act on the results. You can review the standard itself on the IEEE Standards Association website.
Key takeaways
- IEEE 1584-2018 is the standard method for calculating arc flash incident energy on systems from 208 V to 15 kV.
- The analysis requires accurate system data — a single-line diagram, protective-device settings, and utility available fault current.
- Arcing duration, driven by how fast protective devices clear a fault, is the biggest factor in incident energy.
- Outputs are incident energy (cal/cm²), the arc flash boundary, PPE requirements, and equipment labels.
- IEEE 1584 calculates the hazard; NFPA 70E governs what you do about it and requires review at least every five years.
- The study should be led by a qualified or PE-licensed engineer — not treated as data entry.
Frequently asked questions
Is IEEE 1584 the same as an arc flash study?
Not exactly. IEEE 1584 is the calculation method used within an arc flash study. The study is the entire process — data collection, modeling, labeling, and documentation — and IEEE 1584 is how the incident energy inside it is calculated.
What voltage range does IEEE 1584-2018 cover?
IEEE 1584-2018 applies to systems from 208 V to 15 kV, with defined parameters for electrode configuration and enclosure size.
How long does an IEEE 1584 analysis take?
It depends on system size and data availability — from a couple of weeks for a small facility to considerably longer for large or multi-building sites. Field data collection is usually the longest phase.
Does IEEE 1584 tell me what PPE to wear?
IEEE 1584 calculates incident energy in cal/cm². NFPA 70E maps that energy to arc-rated PPE requirements, which then appear on the equipment label.
How often does an IEEE 1584 study need updating?
Review it at least every five years per NFPA 70E, or sooner whenever equipment, protective-device settings, or available fault current change.