Preparing for an arc flash study means assembling six things before the engineer arrives: one-line diagrams, panel schedules and switchgear layouts, transformer nameplate data, breaker and fuse makes, models and settings, cable sizes, types and lengths, and motor horsepower and load data. Then arrange escort access to every electrical room.
If you manage an industrial plant, commercial facility, or utility system, an arc flash study isn't just a compliance checkbox—it's a critical step in protecting your personnel and your equipment. The better you prepare for the study, the more accurate and valuable your results will be.
At PowerSafe Engineering, we've performed countless studies across manufacturing, healthcare, wastewater, and energy sectors. Here's our step-by-step guide to ensure your arc flash study is smooth, efficient, and delivers actionable results.
Step 1 – Why Do You Need an Arc Flash Study?
Arc flash studies are required under NFPA 70E, OSHA, and industry best practices. They determine the incident energy levels at various points in your electrical system and help define the PPE requirements, arc flash boundaries, and labeling needed to keep your team safe. Preparation starts with knowing the goal—to protect workers, comply with standards, and reduce the likelihood and severity of arc flash events.
Step 2 – What Documentation Should You Gather?
Accurate, up-to-date documentation is the backbone of a reliable study. Before your engineering team arrives, compile:
- One-line diagrams of your electrical system
- Panel schedules and switchgear layouts
- Transformer nameplate data
- Breaker and fuse information (make, model, and settings)
- Cable sizes, types, and lengths
- Motor horsepower and load data
If this information is incomplete, don't worry—our engineers can gather it during the site visit, but having it ahead of time speeds the process.
Step 3 – What Happens During the Site Visit?
The field assessment allows us to verify your documentation, capture missing details, and note real-world conditions that drawings may not reflect. This includes:
- Checking for equipment upgrades or changes since your last study
- Measuring conductor lengths and routing
- Documenting protective device settings
- Identifying any safety hazards in the electrical rooms
Pro tip: Arrange for escort access to all electrical rooms and ensure that panels are unlocked and available for inspection.
Step 4 – Who Should Be Involved?
An arc flash study isn't just for engineers—it's a team effort. Key personnel to include are:
- Maintenance staff who know the electrical system inside and out
- Safety officers responsible for compliance
- Facility managers who schedule downtime and coordinate operations
Having the right people available during data collection avoids repeat visits and ensures nothing is overlooked.
Step 5 – Will You Need to Shut Anything Down?
Most of the data collection is non-invasive and can be done without shutting down your facility. However, in some cases, breaker or relay settings may need to be verified, which might require brief outages. Work with your engineering team to schedule these during low-impact periods.
Step 6 – What Is in the Draft Report?
Once the modeling and calculations are complete, we'll provide a draft report showing:
- Incident energy values at each bus or piece of equipment
- Arc-rated PPE requirements based on calculated incident energy
- Arc flash boundaries
- Coordination adjustments to reduce hazard levels
Reviewing this draft allows you to provide feedback before finalizing the report and printing arc flash labels.
Step 7 – What Do You Do With the Results?
An arc flash study is only as effective as its follow-up. Implementation may include:
- Applying new arc flash labels
- Updating your electrical safety program
- Adjusting protective device settings for better coordination and hazard reduction
- Training your team on new PPE and work procedures
Final Thoughts
Preparation is the key to getting the most value from your arc flash study. The more organized your data and team are, the faster we can deliver accurate results that improve safety and compliance. If you want to see where all this preparation leads, what an arc flash study includes and a redacted sample report are both published on this site.
If your facility is due for a study—or it's been more than five years since your last one—contact PowerSafe Engineering today. We'll guide you through the entire process, from preparation to implementation, ensuring your people and equipment are protected.