Build safer electrical systems with this electrical arc flash hazard management guide for assessing risks, strengthening controls, and maintaining facility reliability.
Key takeaways
- Accurate electrical data provides the foundation for reliable arc flash assessments.
- Arc flash labels communicate assessment results but don’t replace risk management.
- Protective device behavior can significantly influence incident energy and worker exposure.
- Electrical system changes can make existing calculations and labels outdated.
- Ongoing arc flash management supports safer maintenance and facility reliability.
Arc flash labels are easy to spot. The warning stickers are attached to switchgear, panels, motor control centers, and other electrical equipment throughout commercial facilities. However, seeing a label doesn’t tell you whether the information behind it is still accurate.
Your facility may have replaced a transformer, added a generator, changed breaker settings, or modified the electrical distribution system since the original assessment. Any of those changes can affect how the system behaves.
Arc flash hazards also aren’t limited to high-voltage equipment. Even lower-voltage systems can create arcs capable of burning exposed skin, igniting clothing, and causing catastrophic injuries.
That’s why effective arc flash management isn’t simply running software and printing labels. The labels are one result of a much larger process involving accurate electrical data, engineering analysis, risk controls, maintenance, and regular review.
So, what are the essential steps for conducting a comprehensive arc flash risk assessment? Dive in for more.
Start with Accurate Electrical System Information
An arc flash study can contain pages of calculations and impressive-looking diagrams. However, none of that carries much value if the electrical system model doesn’t match what’s actually installed.
Accurate data should include:
- Current one-line diagrams showing the electrical distribution system
- Equipment and nameplate data for transformers, switchgear, panels, and other components
- Protective device settings for breakers, fuses, and relays
- Utility and source information affecting available fault current
- Generator, UPS, and alternate-source configurations
- Maintenance records showing equipment condition and previous changes
Field verification is especially important when drawings are old or several modifications have occurred over the years. A breaker setting shown on a drawing doesn’t help much if somebody changed the actual setting during a previous project.
The basic principle is simple: you can’t manage electrical risk without knowing the electrical system you actually have.
Evaluate Hazards Through a Complete Engineering Process
Once the electrical model is verified, the assessment moves into the engineering work behind the final arc flash results.
That process generally connects these six analyses:
- Verified electrical system: Establish the facility’s current configuration.
- Short-circuit analysis: Determine available fault current at relevant equipment.
- Protective device evaluation: Review how breakers, fuses, and relays respond.
- Arc flash calculation: Evaluate the potential energy produced during an arc.
- Incident energy evaluation: Determine potential worker exposure.
- Risk controls: Identify practical ways to reduce the remaining risk.
Software is useful here, but software can’t decide whether the information entered into it makes sense. Engineering judgment still matters when evaluating system configurations, protective device behavior, equipment condition, and operating scenarios.
One point is particularly important. Higher fault current doesn’t automatically produce the highest arc flash exposure. Protective device clearing time also affects incident energy. In some cases, lower fault current may cause a protective device to operate more slowly, increasing the duration of the arc.
So, focusing on one number without understanding how the system responds can lead to the wrong conclusion.
Use the Hierarchy of Controls to Reduce Risk, Not Just Manage Exposure
When an assessment identifies a serious arc flash exposure, buying heavier personal protective equipment shouldn’t automatically become the entire solution.
PPE has an important role, but it sits at the lower end of the hierarchy of controls. The preferred approach is to address the hazard closer to its source whenever practical.
The hierarchy includes:
- Elimination: Establish an electrically safe work condition whenever possible.
- Substitution: Replace a process or component with a lower-risk alternative where practical.
- Engineering controls: Change the system to reduce the hazard or worker exposure.
- Awareness: Use signs, labels, and other methods to communicate the hazard.
- Administrative controls: Apply procedures, training, work practices, and planning.
- PPE: Use appropriately selected arc-rated equipment for the remaining exposure.
Engineering controls may include faster protective device operation, maintenance switching, remote operation or racking, protection upgrades, and arc-resistant equipment where appropriate.
The goal isn’t simply to dress someone for a larger hazard. Where practical, it’s better to reduce the hazard he or she is being exposed to in the first place.
Treat Labels, Documentation, and Maintenance as Part of the Safety System
Arc flash labels communicate useful information to the equipment. However, the sticker itself isn’t the safety program. According to NFPA 70E arc flash assessment, data should be reviewed for accuracy at intervals not exceeding five years, and labels should be updated when system changes make them inaccurate.
A stronger program also includes accurate, up-to-date labels; controlled electrical drawings and equipment records, current protective device settings, supporting documentation, proper training and procedures, and relevant maintenance information.
Change management also becomes important, because electrical systems rarely remain exactly as originally designed.
For example, your facility may:
- Replace a transformer
- Add a generator or uninterruptible power supply (UPS)
- Change breaker or relay settings
- Expand electrical distribution
- Reconfigure normal and alternate sources
Those modifications can affect the calculations behind existing labels.
Rather than treating the arc flash report as something finished and filed away, facility managers should treat the electrical model as information that needs to remain current.
Build an Ongoing Arc Flash Management Plan
Completing the assessment gives you a baseline. The next challenge is keeping that baseline useful.
Someone should have responsibility for maintaining the electrical model and making sure relevant changes are captured. One-line diagrams should stay current, equipment modifications should be documented, and maintenance teams should know when a change may require engineering review.
Regular maintenance also plays an important role in managing electrical hazards, especially as equipment ages or facility conditions change.
An ongoing plan should cover:
- Ownership of electrical drawings and system models
- Equipment-change documentation
- Current protective device information
- Maintenance coordination
- Periodic assessment reviews
- Updates following significant system modifications
Besides supporting safety, that discipline can make maintenance easier. Your team has better information when planning outages, troubleshooting equipment, coordinating contractors, or deciding whether an electrical modification creates another problem somewhere else.
That’s where arc flash management begins supporting overall facility reliability as well as worker safety.
Make Arc Flash Safety an Ongoing Process
Arc flash safety is a process, not a sticker. A label may tell you what an assessment found at one point in time, but lasting risk management depends on the electrical system, protective devices, documentation, maintenance, and people behind that label.
A useful electrical arc flash hazard management guideline therefore comes back to four priorities:
- Understand the system
- Evaluate the actual hazards
- Reduce exposure through appropriate controls
- Keep your information current as the facility changes.
Universal Electrical Services helps commercial facility teams evaluate electrical conditions and identify issues before they create larger safety or reliability problems. Our electrical inspections can support informed decisions about existing infrastructure, maintenance needs, and potential electrical risks.
Need help evaluating your facility’s electrical system? Talk to UES about your commercial electrical assessment needs.
Frequently Asked Questions
1. What Is an Arc Flash Risk Assessment?
It evaluates electrical hazards, potential exposure, and suitable risk controls.
2. Why Isn’t Installing Arc Flash Labels Enough?
Labels communicate hazards, but they don’t replace assessment, maintenance, training, or risk controls.
3. What Information Is Needed Before an Arc Flash Assessment?
Current one-line diagrams, equipment data, protective device settings, utility data, and maintenance records.
4. How Often Should an Arc Flash Assessment Be Updated?
Review it periodically and whenever significant electrical system changes occur.
5. Can Electrical System Changes Affect Existing Arc Flash Labels?
Yes. Equipment, settings, or configuration changes can alter incident energy results.
6. Does Heavier PPE Solve a High Arc Flash Hazard?
No. PPE reduces exposure but doesn’t remove the underlying hazard.
7. What Role Does Maintenance Play in Arc Flash Risk?
Proper maintenance helps protective devices operate as expected during a fault.
8. How Can Facility Managers Reduce Arc Flash Risk?
Keep system data current, maintain equipment, document changes, and apply suitable controls.
