What Is an Arc Flash Study and Why Your Facility Needs One
- Stephen Fike
- Mar 15
- 5 min read
Electrical systems power nearly every aspect of modern facilities—from manufacturing lines and hospitals to data centers and commercial buildings. While these systems are essential, they also introduce significant safety risks when not properly analyzed and maintained.
One of the most serious electrical hazards is an arc flash—a sudden release of electrical energy that can cause catastrophic injuries, fires, and equipment damage.
To manage this risk, organizations rely on an arc flash study. These studies help facilities understand electrical hazards, establish safe work practices, and comply with safety standards such as NFPA 70E and OSHA regulations.
In this guide, we explain what an arc flash study is, how it works, and why every facility operating electrical equipment should consider one essential.
Understanding the Basics of an Arc Flash Study
An arc flash study is a detailed engineering analysis of an electrical power system. Its purpose is to determine the potential hazards associated with arc flash incidents.
During an arc flash event, electricity jumps through the air between conductors or to ground. This produces:
Extreme heat (up to 35,000°F)
Intense pressure waves
Molten metal spray
Blinding light
These conditions can cause severe burns, blindness, hearing damage, or even death.
An arc flash study evaluates your facility's electrical distribution system to determine the incident energy levels that workers could be exposed to during a fault.
The study then calculates safe working distances, required PPE levels, and protective device settings.
Ultimately, the goal is simple: Protect workers and reduce the risk of catastrophic electrical accidents.
Why Arc Flash Hazards Are So Dangerous
Arc flash incidents are among the most severe electrical hazards in industrial environments.
A typical arc flash explosion can release the same energy as several sticks of dynamite. Within milliseconds, temperatures can vaporize copper conductors and produce a shockwave strong enough to throw workers across a room.
Some consequences of arc flash incidents include:
Third-degree burns
Permanent nerve damage
Lung injuries from superheated air
Flying metal shrapnel
Equipment destruction
Facility downtime
According to the Electrical Safety Foundation International, thousands of workers are treated for electrical burn injuries each year. Without an arc flash study, facilities may unknowingly expose workers to these hazards.
Key Components of an Arc Flash Study
An effective arc flash study includes several critical engineering steps.
1. Data Collection
Engineers begin by gathering detailed electrical system information, including:
Single line diagrams
Transformer ratings
Cable sizes and lengths
Protective device settings
Panelboards and switchgear details
Accurate data is essential for reliable hazard calculations.
2. Short Circuit Analysis
Short circuit analysis calculates the maximum fault current available in the system.
This helps determine how much electrical energy could be released during a fault event.
Understanding these values is necessary for protective device coordination and safety planning.
3. Protective Device Coordination
Protective devices such as circuit breakers and relays must operate in a coordinated sequence.
A coordination study ensures the device closest to the fault trips first, minimizing system damage and reducing arc flash energy levels.
4. Incident Energy Calculations
Engineers calculate the potential energy exposure workers may experience at different points in the electrical system.
These calculations determine:
Arc flash boundaries
Required PPE levels
Safe working distances
5. Arc Flash Labeling
Once the study is complete, equipment must be labeled with safety information.
Arc flash labels typically include:
Incident energy level
Arc flash boundary
PPE category
Nominal system voltage
These labels help workers quickly identify hazards before performing maintenance.
Why Your Facility Needs an Arc Flash Study
There are several reasons why conducting an arc flash study is essential for industrial and commercial facilities.
1. OSHA Compliance
The Occupational Safety and Health Administration requires employers to protect workers from electrical hazards.
Although OSHA does not mandate arc flash studies specifically, regulations such as 29 CFR 1910.333 and 1910.335 require hazard assessment and proper PPE selection.
An arc flash study provides the documentation needed to demonstrate compliance.
2. NFPA 70E Requirements
The NFPA 70E standard strongly recommends performing arc flash risk assessments.
Facilities that follow NFPA 70E guidelines significantly reduce the likelihood of electrical injuries and liability issues.
You can review the standard here:https://www.nfpa.org/70E
3. Protecting Workers
The most important reason to perform an arc flash study is worker safety.
Proper analysis ensures employees know:
Where hazards exist
What PPE to wear
How far they must stand from energized equipment
These precautions can prevent life-altering injuries.
4. Reducing Equipment Damage
Arc flash incidents can destroy expensive electrical infrastructure including:
Switchgear
Transformers
Motor control centers
Distribution panels
A study helps optimize protective devices to minimize damage and reduce repair costs.
5. Lowering Insurance and Liability Risks
Electrical accidents often lead to:
Worker compensation claims
OSHA fines
Lawsuits
Facility shutdowns
Insurance companies increasingly request arc flash documentation before issuing policies.
6. Improving Electrical System Reliability
Arc flash studies often reveal system design flaws or outdated protective settings.
Correcting these issues improves power reliability and prevents unexpected outages.
How Often Should an Arc Flash Study Be Updated?
Electrical systems evolve over time. New equipment, upgrades, or changes in utility service can affect arc flash calculations.
Industry best practices recommend updating an arc flash study:
After major electrical modifications
After utility changes
When protective devices are replaced or reset
Keeping studies current ensures accurate safety information.
Industries That Require Arc Flash Studies
Arc flash hazards exist anywhere electrical power systems operate.
Common industries that benefit from arc flash studies include:
Oil and gas facilities
Data centers
Hospitals
Commercial buildings
Utilities
Food processing plants
Chemical processing facilities
Facilities with large electrical distribution systems face the highest risk.
How Professional Engineering Firms Conduct Arc Flash Studies
Professional electrical engineers use specialized software such as:
ETAP
SKM PowerTools
EasyPower
These tools model the entire electrical distribution system to simulate fault conditions and calculate incident energy levels.
Engineering teams then provide:
Detailed reports
Safety recommendations
Updated single-line diagrams
Arc flash labels
This information helps facilities implement safer electrical work practices.
Benefits of Working With Certified NDT and Inspection Providers
Partnering with experienced engineering and inspection firms ensures your arc flash study meets industry standards.
Professional providers deliver:
Accurate system modeling
Compliance with NFPA and OSHA regulations
Detailed hazard documentation
Expert safety recommendations
Organizations such as Assured NDT provide specialized inspection and testing services that help facilities identify electrical risks and maintain safe operations.
Frequently Asked Questions (FAQ)
What is the purpose of an arc flash study?
The purpose of an arc flash study is to analyze an electrical system and determine the potential energy released during an arc flash incident. The study identifies hazards and provides safety measures to protect workers.
Is an arc flash study required by OSHA?
OSHA does not explicitly require an arc flash study, but it requires employers to perform electrical hazard assessments and provide appropriate PPE. An arc flash study helps meet these requirements.
How long does an arc flash study take?
The timeline depends on the size and complexity of the facility. Small facilities may take a few weeks, while large industrial plants may require several months.
How much does an arc flash study cost?
Costs vary depending on system size and complexity. Small facilities may cost a few thousand dollars, while large industrial studies can range significantly higher.
What equipment requires arc flash labeling?
Equipment likely to require maintenance while energized must be labeled, including:
Switchboards
Panelboards
Motor control centers
Industrial control panels
When should arc flash labels be updated?
Labels should be updated whenever the electrical system changes or when the arc flash study is updated, typically every five years.
