Engineer Assisted Arc Flash Studies: A How to Guide
September 16, 2025
Arc flash incidents remain one of the most dangerous hazards in industrial and commercial electrical systems. An arc flash study is not just a regulatory necessity—it’s a vital part of safeguarding workers and assets. At Herzig Engineering, our Professional Engineers (P.E.s), licensed nationwide, ensure every study is accurate, actionable, and fully compliant with NFPA 70E and OSHA requirements.
In this blog, we will explore what arc flash studies are, why they matter, and how companies can choose between turnkey solutions and engineer-assisted studies.
Continue reading to get a complete overview of the arc flash study process, regulatory requirements, and practical guidance for organizations deciding how to approach compliance.
Watch the webinar recording below the blog!
What Is an Arc Flash and Why Does It Matter?
An arc flash occurs when an electrical current deviates from its intended path, often due to equipment failure, dust buildup, degraded components, human error, or even small animals entering enclosures. This creates a massive release of energy in the form of:
Extreme heat and intense flash
Molten and vaporized material
Explosive pressure waves
Deafening sound waves
Shrapnel
The result can be catastrophic injuries or fatalities. Because of the severity of these events, OSHA requires employers to protect workers from arc flash hazards, with NFPA 70E providing the industry standard framework for compliance.
Regulatory Requirements for Arc Flash Studies
OSHA mandates that employers identify and mitigate arc flash risks. NFPA 70E specifies how to meet those requirements, including:
Labeling: All equipment likely to be serviced while energized must be labeled with voltage, arc flash boundaries, and PPE requirements.
Incident Energy Analysis: The most accurate way to calculate arc flash hazards, expressed in calories per centimeter squared (cal/cm²).
Updates: Arc flash studies must be reviewed and updated at least every 5 years, or sooner if system modifications occur (e.g., new transformers, breakers, or reconfigured loads).
Standards: Calculations follow IEEE 1584 guidelines (latest 2018 edition), which significantly improved accuracy based on new testing data.
Skipping these steps is not an option. Even if a company has a strict “no energized work” policy, equipment must still be verified as de-energized before servicing—which requires appropriate arc flash calculations and labeling for protection.
The Arc Flash Study Process: Step by Step
1. Data Collection
Qualified electricians or engineers gather system data: wire types, lengths, impedance, transformer ratings, breaker and fuse settings, motor and generator nameplate details, etc.
This work requires specialized knowledge but does not typically require a shutdown.
2. System Modeling
Engineers input data into software such as SKM Power Tools to create a one-line diagram of the electrical distribution system.
Short-circuit and arc flash calculations are performed, along with protective device coordination checks.
3. Hazard Mitigation
Engineers provide recommendations for lowering incident energy, often through breaker setting adjustments or protective device upgrades.
These small changes can significantly reduce arc flash hazards.
4. Client Review
Reports and diagrams are shared with facility teams for verification and decision-making about mitigation steps.
5. Label Creation and Application
Durable arc flash labels are printed and applied directly to equipment such as switchboards, panel boards, disconnects, MCCs, and bus ducts.
Labels must be applied carefully and consistently to avoid mislabeling, which can lead to serious safety risks.
6. Finalized Study
A professional engineer reviews, stamps, and signs the final report.
Facilities receive one-line diagrams, hazard reports, and labels, plus training on how to interpret and use the results.
Turnkey Arc Flash Studies vs. Engineer-Assisted Studies
Companies generally have two main options for completing arc flash studies:
Turnkey Solution
Herzig (or another provider) completes the process from start to finish.
Benefits:
Experts handle everything
No interruption to operations
Professional quality control on labels and calculations
Includes safety training
Considerations:
Higher upfront investment due to travel and on-site time
Engineer-Assisted Study
Facility staff handle data collection and label application, while engineers provide oversight, calculations, and reports.
Benefits:
Cost savings from reduced site visits
Staff involvement can strengthen electrical safety culture
Considerations:
Requires highly qualified, available personnel
More time-consuming for in-house teams
Greater risk of misapplied or outdated labels
Deciding Which Option Is Best
When choosing between turnkey and engineer-assisted arc flash studies, ask:
Do you have highly qualified electrical personnel on staff?
Only experienced electricians or engineers should handle data collection and labeling.
Do they have the time to do it properly?
The process is detailed and time-consuming. Cutting corners increases risk.
Can labeling be verified?
A second set of eyes is recommended to cross-check labels against one-line diagrams.
If the answer to any of these is no, a turnkey solution may be the safer and more reliable route. However, for organizations with skilled teams and strong safety programs, engineer-assisted studies can reduce costs and build internal ownership.
Key Takeaways
Arc flash events are among the most dangerous hazards in electrical work.
OSHA requires employers to address arc flash risks, with NFPA 70E outlining how.
Studies must be updated at least every 5 years—or sooner if the system changes.
Turnkey solutions offer convenience and peace of mind, while engineer-assisted approaches require in-house expertise may lower costs.
Labels must always be accurate, consistent, and verified to prevent dangerous mistakes.
Final Thoughts
Whether you choose a turnkey arc flash study or an engineer-assisted approach, the goal is the same: protecting workers from life-threatening hazards and ensuring compliance with OSHA and NFPA standards.
Arc flash studies aren’t just about checking a compliance box—they’re about saving lives, protecting assets, and fostering a strong culture of electrical safety.
NFPA 70E requires that arc flash studies be reviewed by a qualified person. At Herzig Engineering, every study is overseen by a P.E., adding credibility and reliability. This not only improves safety outcomes—it also reduces liability and speeds up compliance reviews during OSHA inspections.
Benefits of Partnering with Herzig Engineering
Nationwide engineering coverage
Consistent quality across all facilities
Centralized client portal for easy report access
Turnkey service options from data collection to label application
Need to Stay Compliant and Safe?
Learn more about our Arc Flash Studies and how our Electrical Safety Audits can enhance your compliance strategy. Ready to take action? Contact us today to schedule your engineer-assisted arc flash study.
Related Services: Arc Flash Study, Infrared Scanning, Electrical Safety Training
Resources
If you missed this live, here’s your chance to catch up.
We’ve added the full webinar replay and key takeaways in this quick blog recap: