When Does Your NYC Facility Need an Arc Flash Study?

If you own or manage a commercial, institutional, or multifamily building in New York City, there’s a reasonable chance your electrical distribution system has never had an arc flash hazard analysis—or the one you have is outdated. That’s a problem, because NFPA 70E requires employers to assess arc flash risks wherever workers may be exposed to electrical hazards, and building owners who can’t produce compliant documentation face real liability exposure.

This post explains what an arc flash study is, when you need one, and what to expect from the process.

An arc flash is an explosive release of energy caused by an electrical fault—a short circuit between conductors or between a conductor and ground. Temperatures at the arc point can exceed 35,000°F. The resulting blast wave, molten metal, and intense light can cause severe burns, hearing loss, and death.

An arc flash hazard analysis models your entire electrical distribution system—from the utility service entrance through switchgear, transformers, panelboards, and downstream equipment—to calculate the incident energy (measured in calories per square centimeter) that a worker would be exposed to at each point. The study then determines the appropriate PPE (personal protective equipment) category and arc flash boundary for every piece of equipment, and produces warning labels that must be affixed to each panel, disconnect, and switchgear section.

The study also typically includes a short circuit analysis (to verify that protective devices have adequate interrupting ratings) and a protective device coordination study (to ensure that the device closest to the fault trips first, rather than shutting down an entire building).

Who Requires an Arc Flash Study?

NFPA 70E (Standard for Electrical Safety in the Workplace)

NFPA 70E is the primary driver. Article 130.5 requires an arc flash risk assessment before any worker performs tasks within the arc flash boundary of energized equipment. This applies to your in-house maintenance staff, your electrical contractors, and anyone else who opens a panel or works on energized equipment in your building. As the building owner or employer, you bear responsibility for ensuring this assessment exists.

OSHA

OSHA does not have a specific arc flash standard, but it enforces arc flash safety under the General Duty Clause (Section 5(a)(1)) and references NFPA 70E as the recognized industry standard. OSHA citations for arc flash incidents in buildings without a current study are increasingly common—and the penalties are significant.

Insurance Carriers

Many commercial property and general liability insurers now require arc flash studies as a condition of coverage or for favorable premium rates. If you’ve received a letter from your insurance carrier requesting arc flash documentation, this is why.

Tenants

Large commercial and institutional tenants—particularly in data centers, healthcare, and financial services—routinely require landlords to provide current arc flash labels and PPE information as part of their lease or fit-out requirements.

When Is a New or Updated Study Required?

An arc flash study is not a one-and-done exercise. NFPA 70E requires that the study be reviewed and updated whenever changes occur that could affect the results. Common triggers include:

• Your utility (Con Edison, National Grid) has upgraded the transformer serving your building or increased available fault current at the service entrance

• You’ve added significant electrical loads—new tenant fit-outs, EV charging stations, electrification conversions from gas to electric heating

• Protective devices have been replaced, added, or re-set (new breakers, fuses, or relay settings)

• You’re renovating, expanding, or reconfiguring the electrical distribution system

• The existing study is more than 5 years old (industry best practice for review cycle)

• You’re acquiring a building and need to evaluate electrical infrastructure as part of due diligence

• An incident, near-miss, or insurance audit has identified gaps in electrical safety documentation

  
  

What Does the Study Include?

A complete power systems study from BUILT Engineers typically includes the following deliverables:

• Field Survey: Data collection and field verification of your electrical system—one-line diagrams, nameplate data, protective device settings, cable lengths and sizes, transformer impedances

• Short Circuit Analysis: Computer modeling of your system using SKM Power*Tools to calculate available fault current at every bus

• Arc Flash Hazard Analysis: Calculation of incident energy levels and PPE categories at each equipment location per IEEE 1584

• Protective Device Coordination: Verification that overcurrent devices trip in the correct sequence to isolate faults and minimize outage scope

• Arc Flash Labels: Compliant warning labels for every panelboard, switchboard, MCC, disconnect, and switchgear section

• Engineering Report: PE-stamped report documenting methodology, assumptions, results, and recommendations

  
  

How Long Does It Take?

For a typical commercial building, expect 2–4 weeks from field survey to final report delivery. Larger campuses, hospitals, and industrial facilities may require 4–8 weeks depending on system complexity. We offer expedited timelines for time-sensitive projects, insurance deadlines, and tenant requirements.

What Does It Cost?

Pricing depends on the size and complexity of your electrical system—primarily the number of buses, protective devices, and voltage levels that need to be modeled. A single-building commercial property with one service entrance and 20–40 protective devices is a very different scope than a multi-building campus with multiple services and hundreds of devices. We provide fixed-fee quotes after reviewing your one-line diagrams or performing a brief site walk.

Why BUILT Engineers?

• PE-Stamped Reports: Every study is reviewed and sealed by a licensed Professional Engineer

• Direct Engineer Access: You work directly with the engineer performing the analysis—no account managers or corporate layers

• NYC Code Expertise: We understand how power systems studies intersect with DOB filings, Con Edison requirements, FDNY coordination, and NYC building code compliance

• Contractor-Friendly: We serve as a subcontracting resource for electrical contractors and MEP firms who need power systems expertise on their projects

Frequently Asked Questions

Q: Is an arc flash study required by law in NYC?

NFPA 70E requires an arc flash risk assessment wherever workers may be exposed to electrical hazards. While NYC does not have a separate local law mandating arc flash studies, OSHA enforces NFPA 70E as the recognized industry standard, and citations under the General Duty Clause carry significant penalties. Many insurance carriers and commercial tenants also require current arc flash documentation.

Q: How often should an arc flash study be updated?

NFPA 70E requires updates whenever changes occur that could affect results—utility upgrades, new loads, protective device changes, or system modifications. Industry best practice is to review and update the study at least every 5 years, even if no changes have occurred.

Q: Do I need an arc flash study for a residential building?

For multifamily residential buildings with common-area electrical rooms where maintenance staff or contractors work on energized equipment, yes—NFPA 70E applies. For small residential properties where only licensed electricians perform work, the electrician’s employer typically bears responsibility for arc flash safety, but the building owner should still verify that current labels are in place.

Q: What is the difference between an arc flash study and a short circuit study?

A short circuit study determines the maximum available fault current at each point in your system and verifies that protective devices have adequate interrupting ratings. An arc flash study uses the short circuit results along with protective device clearing times to calculate incident energy levels and PPE requirements. The two studies are typically performed together.

Q: Can BUILT Engineers perform power studies for buildings outside of NYC?

Yes. We are licensed to perform power systems studies throughout New York State and the Tri-State area. Contact us for projects in other jurisdictions.

Need an Arc Flash Study for Your NYC Building?

Contact BUILT Engineers for a free consultation and fixed-fee quote.

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