Why Our Arc Flash Studies Go Beyond Labels

An arc flash study should do more than tell you how dangerous your electrical equipment is. It should help you understand what to do about it. We have seen many studies that provide the owner with the incident energies, but don't actually do anything about them. 

At TRM Engineering, we believe this is one of the biggest differences between a basic arc flash study and a useful one. Yes, arc flash labels are important. They communicate key information such as available incident energy, arc flash boundaries, voltage, and PPE requirements. But if a study ends with labels and no practical recommendations, it may leave the owner with a serious problem: equipment that is labeled, documented, and still too dangerous to work on.
​
That is where experience matters.

​Labels Identify the Hazard. Recommendations Help Reduce It.

​In many facilities, we find equipment with incident energy levels so high that energized work should not be performed. In those cases, simply applying a high-calorie warning label does not solve the underlying issue. It warns workers, but it does not make the equipment safer.

And in the real world, this creates challenges.

Critical equipment still needs to be operated, maintained, tested, and repaired. When the only guidance is “do not work energized,” facility teams may be left without a practical path forward. Worse, when production, uptime, or emergency repairs are on the line, workers may be tempted to ignore high-energy warnings just to get the job done. We have experience working in operating plants and understand these constraints firsthand. 

​That is exactly the situation an arc flash study should help prevent.
​
The better approach is to identify where the hazard is too high, then evaluate ways to reduce the available incident energy so future work can be performed more safely when energized work is justified and unavoidable. The priority is always worker safety. But good engineering also recognizes that facilities need practical solutions that support long-term operation.

How Arc Flash Energy Can Often Be Reduced

Arc flash energy is heavily affected by how much fault current is available and how long it takes protective devices to clear a fault. In many cases, the most effective improvements come from reducing clearing time.

Depending on the system, recommendations may include:

• Adjusting protective device settings to reduce arc duration
• Improving selective coordination while still reducing high incident energy areas
• Adding maintenance switches or energy-reducing maintenance settings
• Using current-limiting fuses or circuit breakers where appropriate
• Adding zone-selective interlocking or differential protection
• Replacing outdated protective devices that no longer provide adequate performance
• Evaluating transformer sizes, feeder arrangements, or system configurations 
• Using remote operation, remote racking, or other methods that move workers farther from the hazard
• Recommending equipment replacement where existing gear cannot be made reasonably safe

These recommendations are not one-size-fits-all. Lowering a breaker setting may reduce arc flash energy, but it can also affect coordination, nuisance tripping, or system reliability. Replacing a fuse may help in one location but create different problems elsewhere. Adding a maintenance switch can be effective, but only if workers understand when and how to use it. Long feeder length, in theory, reduces impedance and reduces current, but can push arcs below instantaneous trip ranges. 
​
That is why the recommendations must come from engineers who understand both arc flash safety and power system behavior. We model the entire system and evaluate not only arc flash energies but also system performance and stability. 

We come across industrial breakers with incorrect settings for proper incident energy protection often

A Common Example: Reducing Incident Energy Without Major Equipment Replacement

One of the most common opportunities we find during arc flash studies is reducing incident energy through relatively simple protective device changes.

In many cases, equipment is not necessarily dangerous because the system is poorly designed. It may be dangerous because the protective devices are not set as effectively as they could be, or because older fuses or breakers do not clear faults as quickly as newer or better-suited options.

For example, we often review systems where a panel or switchboard has a very high calculated incident energy level. At first glance, the result may suggest that energized work should not be performed there at all. But after reviewing the upstream protective devices, available fault current, and coordination requirements, we may find that the incident energy can be significantly reduced with a protective device settings change, a fuse replacement, or another targeted adjustment.

These changes are not always expensive or complicated, but they require engineering review. A lower breaker setting may reduce arc flash energy, but it also needs to be evaluated against the facility’s load requirements and coordination needs. A different fuse may clear faster during an arcing fault, but it still needs to be appropriate for the equipment and system design.
This is why recommendations matter.

Without that extra engineering step, the facility may be left with a high-calorie label and no clear path forward. With the right review, that same location may be improved to a level where necessary energized tasks can be performed with proper PPE and safer work practices.
​
Not every hazard can be reduced with a simple change, but many can. That is one of the reasons we believe an arc flash study should always include practical recommendations, not just calculations and labels.

The Goal Is Not Just Compliance. The Goal Is Safer Work.

An arc flash study is often viewed as a compliance requirement, but it should be much more than that. It is a tool for understanding risk.

A strong study should answer questions like:
​
Where is energized work not acceptable?
Where is the incident energy higher than practical PPE limits?
Where can settings or equipment changes reduce the hazard?
Where are workers most likely to interact with dangerous equipment?
What changes would provide the biggest safety improvement for the cost?
How can the facility maintain reliability while improving electrical safety?

These are the questions that matter after the labels are printed.

When we perform an arc flash study, we do not just calculate values and walk away. We review the results, identify problem areas, and provide recommendations where conditions are too dangerous or could reasonably be improved. Sometimes the best answer is a settings change. Sometimes it is a procedure change. Sometimes it is equipment replacement. And sometimes the answer is clear: this equipment should not be worked on while energized.
​
But even then, the conversation should not stop there. If energized work is not safe, the facility needs a plan. That may include outage planning, alternate feeds, remote switching options, equipment upgrades, or revised maintenance procedures.

Why Experience Makes a Difference

Arc flash studies require accurate modeling, field data, protective device analysis, and engineering judgment. Software can calculate incident energy, but software alone does not decide what should be done with the results.

That is where a specialized engineering team can provide real value.

An experienced team can look at the system as a whole and help determine which recommendations are practical, which are cost-effective, and which could unintentionally create new problems. The goal is not to make the numbers look better on paper. The goal is to improve safety in a way that works in the real facility.

At TRM Engineering, we approach arc flash studies with that mindset. We believe the study should help owners make informed decisions, reduce risk, and give workers clear guidance they can trust.

Because when incident energy is too high, a sticker is not enough.
​
The real value of an arc flash study comes from understanding the hazard, reducing it where possible, and creating a safer path forward for the people who keep your facility running.