What this is
What is an arc flash study?
What is an arc flash study?
An arc flash study is an engineering calculation of the incident energy an arc could deliver at a given point in the electrical system, carried out using fault current, protection device clearing time and working distance. It produces the numbers behind the label: incident energy, arc flash boundary, and the PPE category needed to work near the panel.
How is an arc flash study different from an electrical risk assessment?
The risk assessment weighs shock, arc flash and burn risk qualitatively for a task. The arc flash study is the quantitative calculation underneath the arc flash part of that assessment, done once per panel rather than per task, and it is what the risk assessment and PPE selection both rely on being current.
Who is competent to carry out an arc flash study?
An electrical engineer trained in the calculation method being used, with access to the single line diagram, protective device settings and fault current data. Reviewing a label without redoing the calculation is not a restudy.
Scope
When is an arc flash study record required?
The study is a system-level engineering exercise, not the check performed before a specific job. Confusing the two produces either a study redone every job or a per-job check skipped because the study exists.
Use this template when
- An installation is new, or the study has never been carried out for the system in question
- A transformer, protective device, protection setting or utility fault level has changed since the last study
- Panel labels are missing, faded, or their basis cannot be traced to a study on record
- A live working justification or PPE selection decision needs a current incident energy figure
- The stated review interval has been reached, as a backstop for change that was not otherwise flagged
Do not use it for
- Energy Isolation Verification, the per-event physical test that stored energy is actually gone before work starts, not a calculation of what it would be
- Electrical Safety Risk Assessment, which weighs shock, arc flash and burn risk for a specific task using the study's outputs, rather than producing them
- Live Working Justification Record, which documents why work is done live and by whom it was authorised, drawing on the boundaries this study sets
- Portable Appliance Test Record, a routine inspection and test cycle for portable equipment with no incident energy calculation in it
- Anything outside KnowSafe, which belongs in the workspace that owns that process
Compliance mapping
Which ISO 45001 cl.6.1.2 requirements does this satisfy?
No regulator prescribes the calculation method in law; IEEE 1584 and NFPA 70E supply the method and PPE tables that a hazard identification duty then requires be acted on.
| Clause | Requirement | Where it lands |
|---|---|---|
| IEEE 1584 | Incident energy and arc flash boundary calculation methodology from fault current, clearing time and working distance | Inputs |
| NFPA 70E Art.130.5 | Arc flash risk assessment to determine likelihood of occurrence and severity of injury | Results |
| NFPA 70E Art.130.7 | PPE selected by incident energy or PPE category, with no PPE recognised above the highest defined category | Results |
| ISO 45001 cl.6.1.2.1 | Hazard identification proactive and ongoing, triggered by change to the system being assessed | Header |
| ISO 45001 cl.8.1.2 | Reduction of risk following the hierarchy of controls, ahead of relying on PPE alone | Reducing the energy |
| ISO 45001 cl.9.1.1 | Monitoring and measurement of the effectiveness of controls, including review of prior assessments | Maintenance of the study |
| ISO 45001 cl.7.5.3 | Documented information available where it is needed, in a form the workforce can use | Results |
What it does not cover
- Energy Isolation Verification, the physical test at the point of work that stored energy is actually gone, which cannot be replaced by a calculation of what the energy would be.
- Electrical Safety Risk Assessment, which weighs task-level risk and consults this study's numbers rather than recalculating them.
- Live Working Justification Record, which records the decision and authorisation to work live, using the boundaries this study sets.
- Electrical Competency Authorisation, which records who is authorised to work at a given PPE category, not what that category is.
- Fixed Installation Inspection, which checks the physical condition of the installation and does not calculate incident energy.
Global
Arc Flash Study Record requirements by country
The calculation method is American in origin and the most widely adopted internationally, but the duty it discharges, current hazard information for anyone working near live equipment, is not.
OSHA General Duty Clause and 1910.333; NFPA 70E as recognised practice
OSHA does not name the calculation method but enforces the outcome, citing employers to NFPA 70E as the industry consensus standard.
An employer without a current study cannot show the PPE selected for live or near-live work was based on anything.
Electricity at Work Regulations 1989, reg.4 and reg.8
No named arc flash study requirement; the duty is to prevent danger from electrical systems and provide suitable protective equipment, assessed generically.
HSE guidance and BS 7671 point toward IEEE 1584 or equivalent calculation as the recognised way to discharge that duty.
ISO 45001 cl.6.1.2 and cl.8.1.2; IEC 61482 for arc-rated PPE
Hazard identification and the hierarchy of controls are management system requirements; IEC 61482 rates PPE against calculated incident energy.
An audit will ask how the incident energy behind a PPE choice was derived and when it was last checked.
How to complete it
How to complete an arc flash study record, step by step
The template records a result. What decides whether it can be trusted is the quality of the inputs behind it, and what happens when the answer is inconvenient.
An estimated figure, used because measured or utility data was unavailable, should carry its own action to obtain the real figure. A study issued on an estimate and never revisited leaves every downstream PPE decision resting on a guess that was never checked.
The calculation assumes the protective device clears the fault at a specific setting. If that setting has drifted, or was never confirmed against the relay or breaker in the field, the incident energy figure describes a system that does not exist.
When calculated energy exceeds what any recognised category covers, the study's job is to force a decision: reduce the energy through protection settings, maintenance mode or remote operation, or mandate the work be done dead. Recording the figure and moving on treats an engineering finding as paperwork.
A study reviewed annually is correct on paper for however long the interval runs and silently wrong the moment a transformer or protection setting changes. Naming those events as triggers, routed through management of change, is what keeps the label attached to the system it actually describes.
What auditors find
Most common arc flash study record findings
Arc flash study findings concentrate on the inputs behind the number and what happens once a panel or a change is inconvenient for the answer.
| Finding | Clause | What fixes it |
|---|---|---|
| Incident energy calculated from estimated fault current, with no action to obtain measured or utility data. | IEEE 1584 | Obtain measured or utility-sourced fault current before labels are issued, or flag estimate-based labels as provisional. |
| Protection settings recorded as assumed rather than field-verified against the relay or breaker. | ISO 45001 cl.6.1.2.2 | Verify protection settings in the field before the study is finalised, and re-verify after protection work. |
| Panel energy above the highest available PPE category, with no mitigation or work-dead decision recorded. | NFPA 70E Art.130.7 | Record the decision to reduce incident energy or work dead; a bare figure above category is not a closed finding. |
| Maintenance switching mode or remote operation not evaluated as a way to reduce incident energy for high-risk panels. | ISO 45001 cl.8.1.2 | Assess maintenance mode and remote operation explicitly for panels feeding routine live or near-live work. |
| Labels at the panel faded, out of date, or not traceable to a study on record. | ISO 45001 cl.7.5.3 | Reconcile the label register against the study whenever either is touched, not on separate schedules. |
| Study not reissued after a documented transformer, protection or utility change. | ISO 45001 cl.9.1.1 | Define the restudy trigger and link it to management of change, so the change itself raises the review. |
Case in point
Case in point: the label that stopped being true
A food processing site had its arc flash study done at commissioning, five years earlier. Panels were labelled Category 2, and maintenance treated the label as settled fact, since nothing about the panels had visibly changed. Eighteen months before the incident, the site added a standby generator for peak chill-store demand and had a utility transformer upgraded as part of an unrelated capacity project.
Neither change was flagged to the study. The added generation and the larger transformer raised available fault current well above what the original calculation assumed, and one panel's true incident energy had moved past Category 2. The gap surfaced during an unrelated protection settings review, not through any process the study itself triggered, and the fix was not a better calculation but a restudy trigger tied to the two events that had gone unreported: transformer changes and standby generation additions.
The template
The template, field by field
The form exactly as it installs. Every field, option, score and conditional rule is editable, and the links to other templates come with it.
5 sections
- Reference
- SAF-157
- Archetype
- Assessment
- Record ID
- AFS-2026-000
- Scoring
- Panels labelled
- Direction
- High is good
- Singleton
- Yes
- Basis
- ISO 45001 cl.6.1.2
- Links
- Links Electrical assessment, PPE
- Tags
- Electrical, Arc flash
- Sections
- 5
- Fields
- 43
- Follow up fields
- 3
- Repeating sections
- 1
- Links out
- 2
Header
12 fieldsStudy ID*
Auto sequence. Format AFS-2026-000.
The record's own ID. Other templates point at this value.
Status*
Drives who this goes to next.
- Planned2 pts
- In progress2 pts
- Complete3 pts
- Deferred0 pts
- Open0 pts
- Closed3 pts
- Overdue0 pts
Date and Time*
Completed By*
Site*
Site ID*
Format SITE-000.
Links to FDN-001 Site ID
Area
The area within the site.
Exact Location
Drop a pin for anything hard to find.
The Label Is Only As Good As The Study
Incident energy depends on fault current and clearing time. Change a transformer or a protection setting and every label downstream is wrong.
Study Scope*
Carried Out By*
Study Standard Applied
Inputs
6 fieldsSingle Line Diagram Current*
- Yes3 pts
- Partly1 pt
- No0 pts
Fault Current Data Obtained*
- Measured4 pts
- From utility3 pts
- Estimated1 pt
Protection Settings Verified*
- Yes3 pts
- Assumed0 pts
Utility Data Obtained
- Yes3 pts
- No0 pts
Standby Generation Included
- Yes3 pts
- Not applicable3 pts
- No0 pts
Working Distance Assumed
Results
Repeats9 fieldsPanel Reference*
Incident Energy*
PPE Category*
- Category 04 pts
- Category 13 pts
- Category 22 pts
- Category 31 pt
- Category 40 pts
- Above category 40 pts
Arc Flash Boundary
Limited Approach Boundary
Restricted Approach Boundary
Energy Above Practical PPE Limit*
Above the highest available PPE category, the only safe answer is to work dead or reduce the energy.
- No3 pts
- Yes0 pts
Label Fitted*
- Yes3 pts
- No0 pts
Label Legible And Current*
- Yes3 pts
- Faded1 pt
- Out of date0 pts
Reducing the energy
5 fieldsProtection Settings Reviewed For Reduction*
A maintenance switching mode that speeds up clearing time cuts incident energy dramatically and costs almost nothing.
- Yes3 pts
- No0 pts
Maintenance Mode Available
- Yes3 pts
- No1 pt
Remote Operation Possible
- Yes3 pts
- No1 pt
High Energy Panels Identified*
Mitigation Recommended
Maintenance of the study
11 fieldsRestudy Trigger Defined*
- Yes3 pts
- No0 pts
Study Review Interval*
- Yes3 pts
- Partly1 pt
- No0 pts
Next Review Due*
Action Required*
Raise the action record, then enter its reference here.
- No2 pts
- Yes0 pts
Priority
- High0 pts
- Medium1 pt
- Low3 pts
CAPA ID
Format CAPA-2026-00000.
Links to FDN-014 CAPA ID
Action Owner
Electrical Engineer*
Signature*
Engineering Manager*
Second Signature*
SAF-157 · record IDs look like AFS-2026-000 · Links Electrical assessment, PPE
Open in KnowellaRun it with agents
From a document you fill in to a programme that runs itself
The calculation is easy to get right once. What fails is the link between the electrical system and the study: the change that never reached it.
Holds the study against the panel and label register, flags panels whose labels cannot be traced to a current study, and routes restudy to the engineer.
Surfaces protective device and transformer changes from work orders so a system change reaches the study as a restudy trigger.
Connects the PPE category on record to the competency and equipment authorisation of the people working at that panel.
Watches for panels above the highest PPE category with no mitigation recorded, and raises restudy when a linked change record suggests the study is stale.
This template lives in KnowSafe — safety and compliance. Incidents, hazards, permits, inspections and the critical controls behind them.
Meet KnowSafe→Glossary
Arc Flash Study Record definitions and key terms
- Incident energy
- The thermal energy an arc could deliver at a given working distance, expressed in calories per square centimetre; the figure that determines PPE category.
- Arc flash boundary
- The distance from a potential arc source at which incident energy falls to the threshold for a second-degree burn, inside which arc-rated PPE is required.
- Approach boundary
- The limited and restricted distances at which shock risk, rather than arc flash, governs what PPE and precautions are needed near exposed conductors.
- PPE category
- A banded classification of incident energy, each specifying a minimum arc rating of clothing; above the highest band, no PPE is recognised as sufficient.
- Maintenance switching mode
- A protection setting trading selectivity for faster clearing time during maintenance work, reducing incident energy for the duration it is engaged.
FAQ
Frequently asked questions about arc flash study record
How often does an arc flash study need to be redone?+
Whenever the system it describes changes: a transformer, a protective device, a protection setting, or the utility's available fault current. The review interval is a backstop for change nobody reported, not the primary trigger.
Can incident energy be calculated from estimated fault current?+
It can be started that way, but a study resting on an estimate should carry its own action to obtain measured or utility data. A label issued from an estimate should be treated as provisional until replaced.
What happens when a panel's incident energy is above the highest PPE category?+
There is no PPE answer. The only acceptable responses are to reduce the incident energy, through protection settings, maintenance mode or remote operation, or to require the work be done dead.
Is IEEE 1584 or NFPA 70E the standard to follow?+
They do different jobs. IEEE 1584 is the calculation method for incident energy and boundaries; NFPA 70E turns those numbers into PPE categories and work practice requirements. A study typically uses both.
Does this study replace the electrical risk assessment?+
No. The risk assessment weighs the task and consults this study's incident energy and PPE category as inputs rather than recalculating them.
Who should carry out the study?+
An electrical engineer competent in the calculation method, with access to the single line diagram, protection settings and fault current data. A restudy that only reviews the existing conclusion is not a restudy.
Keep going
Related templates and programmes
Industries this is written for
Programmes this belongs to
Used together in Electrical Safety and Arc Flash
Energy Isolation Verification
Records the physical test proving stored energy is gone before work begins
Electrical Safety Inspection
Checks panels, cords, outlets and portable equipment for damage and safe access
Electrical Safety Risk Assessment
Assesses shock, arc flash and burn risk from work on or near electrical systems
Live Working Justification Record
Records why work is being carried out live rather than dead, and who accepted that decision
Portable Appliance Test Record
Records inspection and testing of portable electrical equipment, with the result and next due date
Fixed Installation Inspection
Records periodic inspection and testing of the fixed electrical installation, with observations classified by urgency
More in Electrical Safety
Electrical Safety Risk Assessment
Assesses shock, arc flash and burn risk from work on or near electrical systems
Live Working Justification Record
Records why work is being carried out live rather than dead, and who accepted that decision
Portable Appliance Test Record
Records inspection and testing of portable electrical equipment, with the result and next due date
Fixed Installation Inspection
Records periodic inspection and testing of the fixed electrical installation, with observations classified by urgency
Electrical Panel Inspection
Checks panels for damage, heat, moisture ingress, labelling, clearance and unauthorised modification
Electrical Competency Authorisation
Authorises a named person to carry out defined electrical activities on this site, with the limits stated
Written and reviewed by
Siddarth Singh
Founder & Chief Executive Officer, Knowella
Certified Safety Professional and industrial and systems engineer with more than a decade inside food supply chain, freight and manufacturing operations. This page was written against the current text of the standards it cites, not against secondary summaries of them.
- Certified Safety Professional (CSP), Board of Certified Safety Professionals
- MBA, University of Chicago Booth School of Business
- MS and BS, The Ohio State University, Industrial and Systems Engineering
- Six Sigma Black Belt
Sources and last review. Reviewed 16 August 2026 against:
- IEEE 1584 — Guide for Performing Arc-Flash Hazard Calculations
- NFPA 70E — Standard for Electrical Safety in the Workplace, Article 130
- ISO 45001:2018 clauses 6.1.2, 8.1.2 and 9.1.1
- Electricity at Work Regulations 1989, regulations 4 and 8 (GB)
This page is general guidance, not legal advice. Confirm requirements with your jurisdiction’s regulator.