Arc Flash Study: The Complete Guide

What Is an Arc Flash Study?

An arc flash study is a formal engineering analysis of your facility's electrical distribution system. Its purpose is to determine how much energy would be released at each electrical panel, switchgear enclosure, and motor control centre if an arcing fault occurred — and from that, what level of personal protective equipment (PPE) a worker would need to survive working on or near that equipment while energized.

An arc flash is the explosive release of energy caused by an electrical fault that produces a sustained arc between conductors. Temperatures at the arc point can reach 35,000°F — roughly four times the surface temperature of the sun. The resulting blast releases a pressure wave, molten metal droplets, blinding ultraviolet light, and intense thermal radiation in milliseconds. Workers without appropriate PPE can suffer fatal burns, blast injuries, and permanent blindness even from indirect exposure. In Ontario, arc flash incidents account for a disproportionate share of serious electrical injuries and fatalities in industrial workplaces.

The study produces a set of engineering deliverables used to manage this hazard: incident energy calculations at every electrical node in the system, arc flash boundary distances indicating how close unprotected workers can approach, required PPE categories for each work location, an updated single-line diagram of your distribution system, and arc flash warning labels affixed to every panel and piece of switchgear.

The calculations are performed using the IEEE 1584-2018 standard — the current edition of the empirically derived arc flash calculation methodology developed by the Institute of Electrical and Electronics Engineers. Software packages such as ETAP and SKM Power Tools implement this methodology, allowing engineers to model your specific electrical system and calculate the incident energy at each location based on actual equipment data, protective device settings, and available fault current from the utility.

Why Is an Arc Flash Study Required?

CSA Z462: The Canadian Electrical Safety Standard

CSA Z462, Workplace Electrical Safety, is the Canadian standard that defines how employers must protect workers from electrical hazards, including arc flash. The current edition is CSA Z462-24. In Ontario, CSA Z462 is incorporated by reference into the province's occupational health and safety regulations, giving it the force of law. Compliance is not voluntary.

The standard's core requirement: before any energized electrical work is performed, the employer must conduct an arc flash risk assessment at each work location and ensure workers are equipped with appropriate PPE. Article 4.3.5.1 of CSA Z462 specifies that this assessment must use the incident energy analysis method described in Annex D — which is the IEEE 1584 calculation methodology. The standard also prescribes that this assessment be reviewed and updated every five years or when the electrical system changes significantly. Learn more about CSA Z462 compliance requirements →

Ontario's Occupational Health and Safety Act

The Occupational Health and Safety Act (OHSA) imposes a broad general duty on Ontario employers to take every reasonable precaution to protect workers. An arc flash study is the industry-accepted means of demonstrating that this precaution has been taken for electrical hazards. When the Ministry of Labour, Immigration, Training and Skills Development (MLITSD) conducts an electrical safety inspection, the absence of a current arc flash study — or the presence of an expired one — is grounds for an order and significant fines. Under OHSA, corporate fines can reach $500,000 per offence. Sectors with the highest electrical complexity — including the petrochemical refineries concentrated along Sarnia's Chemical Valley corridor, where multiple high-voltage switchgear lineups and large motor control centres are standard infrastructure — tend to attract the most rigorous MLITSD electrical safety inspections.

Bill C-45: Personal Criminal Liability

Bill C-45, the Westray Amendment to Canada's Criminal Code, creates personal criminal liability for individuals who direct work. If a worker is killed or seriously injured as a result of negligent management of workplace safety, supervisors, managers, facility directors, and corporate officers can face criminal charges — not merely administrative penalties. The Bill C-45 standard is negligence, not intent. An employer who knew their arc flash study was expired and failed to act has substantially less legal protection than one who maintained current documentation. Arc flash studies are among the clearest demonstrations of electrical safety due diligence available to Ontario employers.

Insurance Requirements

Many commercial property and general liability insurers now explicitly require current arc flash studies as a condition of coverage for industrial facilities. Following an arc flash incident at an unprotected facility, insurers have successfully denied claims on the basis that the employer failed to meet the minimum safety standards required by CSA Z462. Healthcare systems, institutional campuses, and research facilities — the profile that dominates Kingston's non-military employment base — are particularly subject to this insurer scrutiny given the critical-load nature of their electrical systems. A current arc flash study is increasingly viewed as a prerequisite for coverage, not merely a recommended best practice. Understand the cost of an arc flash study relative to the risk →

What Happens During an Arc Flash Study?

A complete arc flash study involves three integrated analyses: a short circuit analysis, a protective device coordination study, and the arc flash hazard analysis itself. Reputable providers deliver all three as a single engagement. Here is what each phase involves.

Step 1: Scoping and Documentation Review

The engagement begins with a scoping call to establish the study boundaries: which buildings and voltage levels are included, whether existing single-line diagrams are available and current, the utility fault current data at your service entrance, and any known system changes since the last study. The provider requests existing documentation — single-line diagrams, panel schedules, protective relay settings, motor control centre schedules, and transformer nameplates. Facilities with complete, current documentation significantly reduce data collection time and overall cost. See how single-line diagram availability affects cost →

Step 2: Site Data Collection

Engineers visit your facility to collect physical data at every electrical node included in the study scope. This includes: equipment nameplate data (transformer kVA ratings, impedance percentages, voltage levels), protective device ratings and settings (breaker trip curves, fuse ampere ratings, relay settings, time-delay settings), conductor sizes and lengths for impedance calculations, and the physical configuration of your distribution system. For a typical mid-size industrial facility with 50–100 panels, data collection typically takes one to two days on site. Large automotive assembly operations — such as the Stellantis plants and tier-one supplier facilities operating in Windsor — often require three to four days of dedicated site time across multiple production buildings and substations.

Step 3: Single-Line Diagram Development or Verification

A single-line diagram (SLD) is a simplified schematic showing your electrical distribution system from the utility service entrance through every transformer, switchgear, panel, and motor control centre. If a current SLD does not exist, the engineer develops one from the site data collected. If one exists but is outdated, it is updated to reflect the current system configuration. The SLD is both a prerequisite for the study calculations and a key deliverable — it remains a permanent record of your system configuration.

Step 4: Short Circuit Analysis

Using the system model built in ETAP, SKM, or equivalent software, the engineer calculates the maximum available fault current at every bus in the system. This analysis determines whether your existing overcurrent protective devices are rated for the fault current they may be required to interrupt — a critical safety check independent of the arc flash calculations. The fault current values also feed directly into the incident energy calculations.

Step 5: Protective Device Coordination Study

The coordination study verifies that your breakers, fuses, and protective relays are set to operate in the correct sequence during a fault — that downstream devices clear faults before upstream devices operate, minimizing the scope of outages and ensuring protective devices are actually capable of clearing faults as designed. Miscoordination is common in facilities that have grown organically over decades — a pattern seen frequently in Kitchener's automotive supplier and advanced manufacturing plants, where successive production expansions have added electrical capacity without system-level coordination reviews. Correcting it can significantly reduce arc flash incident energy values at downstream equipment, sometimes eliminating the need for Category 3 or 4 PPE at locations where Category 1 or 2 is sufficient.

Step 6: Incident Energy Calculations (IEEE 1584-2018)

With the system model complete and protective device settings verified, the engineer runs the arc flash incident energy calculations at every node. The IEEE 1584-2018 methodology calculates the incident energy (in calories per cm²) at a standardized working distance for each piece of equipment, along with the arc flash boundary — the distance at which incident energy reaches 1.2 cal/cm², the threshold for a second-degree burn. These values determine the required PPE category for each work location.

Step 7: Arc Flash Label Creation

The calculated values are translated into arc flash warning labels for every panel, switchgear enclosure, and MCC. Labels specify: the incident energy level, the arc flash boundary, the required PPE category, the working distance used in the calculation, and the date of the study. Labels must comply with ANSI Z535.4 formatting requirements and be printed on durable, UV-resistant, adhesive-backed material. These labels are physically affixed to equipment before energized work resumes following the study.

Step 8: Final Report Delivery and Review

The engineer delivers a sealed report — stamped by a Professional Engineer licensed in Ontario — containing the complete study findings: all incident energy calculations, short circuit analysis results, coordination study findings, the updated single-line diagram, the arc flash label schedule, and PPE recommendations for every work location. A qualified provider will walk your safety team through the findings, highlight high-incident-energy locations, and recommend any protective device setting changes that could reduce hazard levels.

How Often Does an Arc Flash Study Need to Be Updated?

CSA Z462 requires arc flash studies to be reviewed and updated at a minimum of every five years. This is not a guideline — it is a mandatory requirement. A study completed in 2019 or earlier has expired. If your study was based on the older IEEE 1584-2002 methodology rather than the current 2018 edition, it should be treated as expired regardless of when it was performed, since the 2018 standard uses a substantially revised calculation method that produces different and generally more accurate results.

Beyond the five-year cycle, CSA Z462 requires an updated assessment whenever the electrical system undergoes a significant change. Changes that mandate a review include:

• Adding, replacing, or re-rating utility transformers or substation equipment
• Changes to the utility service configuration or available fault current level
• Installation of new switchgear, motor control centres, or distribution panels
• Significant changes in connected load (adding or removing large motors)
• Modifications to protective relay or fuse settings
• Adding distributed generation, co-generation, or battery energy storage systems
• Physical reconfiguration of the distribution system (new feeders, bus tie changes)
• Facility expansion or major renovation involving the electrical system

Capital-intensive facility upgrades are among the most frequent mid-cycle triggers across Ontario — hospital expansions at London's health sciences campus, new production lines at the Toyota and automotive supplier facilities in Cambridge, and ongoing substation upgrades at Northern Ontario mining operations all commonly prompt arc flash study updates well before the five-year deadline arrives.

The good news: five-year updates are significantly less expensive than initial studies. When a provider can update an existing software model rather than building one from scratch, the engineering time is substantially reduced. Expect to pay roughly 30% less for a five-year update compared to the original study cost, assuming the existing model and single-line diagrams are available.

Arc Flash Study vs. Arc Flash Risk Assessment vs. Arc Flash Analysis

If you have searched for this service, you have likely encountered several different names for what appears to be the same thing. These terms are used interchangeably across the industry:

• Arc flash study
• Arc flash risk assessment (CSA Z462 preferred term; Article 4.3.5.1)
• Arc flash analysis
• Arc flash hazard analysis
• Arc flash hazard assessment
• Arc flash assessment
• Electrical hazard analysis

The term varies by provider, region, and the standard being referenced — CSA Z462 in Canada versus NFPA 70E in the US. When comparing proposals, ensure you are comparing equivalent scope. The key question is whether the scope includes: IEEE 1584-2018 incident energy calculations, a short circuit analysis, a coordination study, a PE-stamped report, arc flash labels, and an updated single-line diagram. If all of these are included, the terminology used is irrelevant.

How to Choose an Arc Flash Study Provider

Not all arc flash study providers are equivalent. The calculations underlying your study determine what PPE your workers wear every day they perform energized work. Errors in those calculations — caused by incomplete data collection, outdated software methodology, or inexperienced engineers — can result in workers being underprotected or over-protected, either of which creates risk.

Essential Qualifications

The study must be performed and sealed by a Professional Engineer (P.Eng.) licensed in Ontario. This is a non-negotiable requirement for regulatory compliance. Electricians, electrical contractors, and safety consultants without a P.Eng. designation cannot legally produce a stamped engineering report in Ontario, regardless of their experience or technical competence.

Look for demonstrated experience with the IEEE 1584-2018 methodology specifically. The 2018 edition was a major revision from 2002 — providers still running the older calculation are producing outdated results. Ask directly: "Which edition of IEEE 1584 does your software implement?"

Confirm the provider uses professional-grade power system analysis software: ETAP, SKM Power Tools, EasyPower, or equivalent. Be cautious of providers using spreadsheet-based calculations or simplified tools for complex systems.

Questions to Ask Before Engaging a Provider

• Is the study performed and stamped by a P.Eng. licensed in Ontario?
• Which edition of IEEE 1584 does your software implement?
• Does the scope include a short circuit analysis and coordination study, or only arc flash calculations?
• What software do you use for system modeling?
• Do you have experience with facilities of our type and size?
• What does your deliverables package include — specifically, does it include arc flash labels?
• What is your typical turnaround time from data collection to final report?
• Will you walk us through the findings and highlight high-hazard locations?
• Can you provide references from similar facilities in Ontario?

Ontario facilities served by our network have access to qualified arc flash study providers in all major cities — from Ottawa and Hamilton to Greater Sudbury and Thunder Bay. Each provider in our network is vetted for P.Eng. credentials, IEEE 1584-2018 proficiency, and experience with Ontario industrial clients.

What You Receive: Arc Flash Study Deliverables

A complete arc flash study from a qualified Ontario provider should include the following deliverables. If a proposal omits any of these, ask why and consider it a red flag.

1. Formal Engineering Report (PE-Stamped)

The central deliverable: a comprehensive engineering report bearing the seal of a Professional Engineer licensed in Ontario. This report contains the complete study findings, including all incident energy calculations, short circuit analysis results, protective device coordination findings, study methodology, assumptions, and recommendations. The PE stamp gives the document legal standing for regulatory compliance purposes.

2. Updated Single-Line Diagram

A current, accurate single-line diagram of your complete electrical distribution system. This document becomes part of your facility's permanent electrical records and is required for future studies, equipment additions, and emergency response. If your existing SLD was incomplete or inaccurate, the updated version produced by the study is often one of its most practically valuable deliverables.

3. Arc Flash Warning Labels

Physical arc flash warning labels for every panel, switchgear enclosure, and MCC covered by the study scope. Labels are printed on durable, UV-resistant, adhesive-backed material compliant with ANSI Z535.4. Each label specifies: incident energy level (cal/cm²), arc flash boundary, required PPE category, working distance, voltage level, and study date. These labels are affixed to equipment before energized work resumes. Learn more about arc flash label requirements →

4. PPE Matrix

A summary table listing each work location, its incident energy level, the arc flash boundary, and the minimum required PPE category. This document gives your safety department a quick-reference tool for pre-task planning and worker PPE selection, and can be integrated into your LOTO procedures or job hazard analysis templates.

5. Coordination Findings and Recommendations

The coordination study findings identify any miscoordinated protective devices and recommend setting changes that would improve both coordination and arc flash hazard levels. In many older Ontario facilities, implementing straightforward relay and breaker setting changes reduces incident energy at multiple locations — sometimes significantly enough to reduce the required PPE category. This is actionable, high-value information your electrical maintenance team can act on immediately.

6. Training Recommendations

CSA Z462 requires that workers authorized to perform energized electrical work receive appropriate training. Most providers include basic training recommendations as part of their report, identifying which locations require Category 1–4 PPE and the specific tasks for which energized work is permitted.

Frequently Asked Questions