| Short Answer: Yes. Any Atlanta data center needs its arc flash study updated before the new equipment is energized. New transformers, switchgear, and utility service change the available fault current and incident energy at every connected point, which makes existing arc flash labels and PPE requirements inaccurate. NFPA 70E sets two separate obligations: the study must be updated whenever a major modification occurs, and it must also be reviewed for accuracy at intervals not exceeding five years. A power expansion is a major modification, so the five-year clock does not apply in place of updating it. |
Metro Atlanta has become one of the most active data center corridors in the country, second only to Northern Virginia by installed power capacity. Hyperscale and colocation operators across Douglas, Fulton, Fayette, and surrounding counties are adding megawatts at a pace that outstrips most maintenance and compliance cycles. Every one of those expansions changes the electrical system in ways that directly affect worker safety. This article explains what an arc flash study is, why a power expansion invalidates the old one, and what data center operators in the Atlanta market need to have in place before the next build phase goes live.
What Is an Arc Flash Study?
An arc flash study is an engineering analysis that calculates the incident energy at every point in an electrical system and assigns the protective measures required to work on or near that equipment safely. At Bowtie Engineering we conduct these as comprehensive incident energy studies aligned with NFPA 70E, IEEE 1584, and OSHA CFR 1910. The output is a set of arc flash labels, a short circuit and protective device coordination analysis, and documented PPE requirements based on real system data rather than generic assumptions.
For a data center, the study covers the utility service entrance, medium voltage switchgear, transformers, UPS systems, distribution panels, and the load side of every protective device. The incident energy at each point determines whether a task can be performed at all, and if so, what arc rated protective equipment is mandatory.
What is incident energy and why does it matter?
Incident energy is the amount of thermal energy released during an arc flash event, measured in calories per square centimeter at a given working distance. It is the single number that determines life or death PPE decisions. A point with low incident energy may allow standard arc rated clothing, while a high energy point may be classified as no safe approach until the system is de-energized. Without a current study, no one on site knows which is which.
Why a Power Expansion Resets the Clock
When a data center adds capacity, it almost always increases the available fault current somewhere in the system. A larger utility transformer, a new service feed, additional parallel UPS modules, or upgraded switchgear all raise the energy that can be delivered into a fault. Higher available fault current changes incident energy at connected equipment, and protective device settings that were correct for the old system may no longer clear faults fast enough.
- New fault current source: Added transformers or utility capacity raise the energy delivered into a fault, increasing incident energy at downstream gear.
- Reconfigured distribution: New tie breakers, paralleled sources, or rerouted feeders change the fault paths the original study modeled.
- Altered protective coordination: Breaker and relay settings tuned for the old lineup may no longer trip in the time the new system requires.
- Outdated labels: Every arc flash label printed from the previous study now states a category and PPE level that may understate the real hazard.
This is why an expansion is not a minor update. It is a system change that triggers the NFPA 70E requirement to revisit the study.
How often does an arc flash study need to be updated?
NFPA 70E sets two distinct requirements. The study must be updated when a major modification to the electrical distribution system occurs, and separately, it must be reviewed for accuracy at intervals not exceeding five years. These are not interchangeable. A data center power expansion is a major modification, which triggers an update regardless of where the facility is in its five year review cycle. Operators that treat the five year mark as the only trigger are working from invalid data the moment new gear is energized.
What Atlanta Data Center Operators Should Have in Place
- A current incident energy study: Completed or revised after the most recent expansion, not before it.
- Accurate arc flash labels: Installed on all affected equipment with correct incident energy, working distance, and PPE category.
- Updated single line diagram: Reflecting the as built system after expansion, since the study is only as accurate as the model behind it.
- Trained personnel: Staff and contractors who can interpret the labels and select PPE correctly, which is a separate requirement under NFPA 70E.
Arc Flash Studies for Atlanta and Nationwide
Bowtie Engineering performs incident energy studies for data centers, manufacturers, and commercial facilities across the Atlanta metro and nationwide on an onsite basis. Our licensed professional engineers collect field data, build an accurate system model, calculate incident energy per NFPA 70E and IEEE 1584, and deliver labels, PPE guidance, and documentation suitable for OSHA review. With more than nine hundred completed programs, we coordinate the study around live facility operations wherever possible.
OSHA enforces electrical safe work practices under 29 CFR 1910 Subpart S, and references NFPA 70E as the consensus standard for compliance. You can review the federal electrical standard directly at OSHA 1910 Subpart S. An arc flash study is the engineering basis that makes compliance with these requirements demonstrable.
Frequently Asked Questions
Does an Atlanta data center expansion legally require a new arc flash study?
NFPA 70E requires the arc flash study to be updated whenever a major modification to the electrical system occurs, and this is a separate obligation from the periodic accuracy review that must happen at intervals not exceeding five years. A power expansion qualifies as a major modification, so it triggers an update regardless of where the facility sits in the five-year review cycle. OSHA enforces NFPA 70E as the consensus standard under 29 CFR 1910 Subpart S. Operating expanded equipment with labels based on the pre expansion study means working from inaccurate hazard data.
How long does an arc flash study take for a data center?
Timeline depends on system size and complexity, but most studies move through field data collection, system modeling, incident energy calculation, and label production. A multi megawatt data center with medium voltage distribution takes longer than a small commercial facility. Bowtie Engineering scopes timeline during the initial assessment.
Can the arc flash study be done without shutting down the data center?
Most field data collection can be performed with the facility energized, since the work involves recording nameplate data, conductor lengths, and protective device settings. Some verification may require limited outages coordinated with the operator. The study itself is engineering analysis performed off site after data collection.
What happens if a facility uses outdated arc flash labels?
Outdated labels can understate incident energy, leading workers to select insufficient PPE for the actual hazard. This exposes personnel to injury and exposes the operator to OSHA citations and liability. The label is only valid if the study behind it reflects the current system.
Does Bowtie Engineering serve data centers outside Atlanta?
Yes. Bowtie Engineering provides onsite incident energy studies nationwide. Atlanta is a primary service area given the regional data center concentration, but the same engineering process applies to facilities anywhere in the United States.
Key Takeaways
- Metro Atlanta is the second largest US data center market, and expansions are outpacing compliance cycles.
- A power expansion changes available fault current, which invalidates the previous arc flash study and labels.
- NFPA 70E requires the study be updated after any major system modification, separate from the periodic five-year accuracy review.
- Operators need a current incident energy study, accurate labels, an updated single line diagram, and trained staff before energizing new gear.
- Bowtie Engineering delivers NFPA 70E and IEEE 1584 incident energy studies for Atlanta data centers and nationwide.
Expanding an Atlanta data center? Schedule an arc flash risk assessment with Bowtie Engineering before your new equipment is energized. Call 866-730-6620.