Arc Flash & Coordination Studies

Short-circuit, coordination, and arc-flash hazard studies for commercial and industrial facilities — performed from Tucson, delivered anywhere in Arizona, and backed by the licensed electrical contractor that can self-perform the corrections.

What We Provide

The full study, not just the labels

Every study starts with field data collection at your facility and a model built in industry-standard power-system analysis software — then we run the engineering that tells you what your system will actually do under fault conditions.

Studies & Analysis

  • Short-circuit / fault-current studies — We calculate the available fault current at each bus and panel so equipment ratings can be verified — underrated gear is one of the most common findings in older Tucson facilities.
  • Protective-device coordination — We set breakers and fuses so the device closest to a fault trips first, isolating the problem instead of blacking out the building.
  • Arc-flash hazard analysis — We calculate incident energy and arc-flash boundaries per NFPA 70E and IEEE 1584, and define the PPE categories your electricians need at each piece of equipment.
  • Load and demand studies — We measure and model how the facility actually draws power, so capacity decisions and additions rest on data instead of nameplate guesses.

Deliverables

  • Study report — Findings, code references, and a prioritized list of corrections in plain language an owner can act on.
  • Updated one-line diagram — An accurate, field-verified one-line of the system as it exists today.
  • Protective-device settings sheets — The exact settings for every adjustable breaker and relay, documented for your records and ours.
  • Printed arc-flash labels — Durable equipment labels with incident energy, boundaries, and required PPE — installed on the gear, not handed over in a box.

Why It Matters

Why owners commission a study

An arc-flash study is not paperwork for its own sake — it is how a facility proves its electrical safety program is real.

  • NFPA 70E requires it — the standard calls for the arc-flash risk assessment to be reviewed at least every five years, or whenever the electrical system changes in a way that could affect the results.
  • Insurers and safety programs ask for it — carriers, safety audits, and many GC prequalification packages now expect current arc-flash labels and a coordination study on file.
  • It protects your people — accurate labels and PPE categories are what stand between a qualified electrician and an incident-energy exposure no one priced in.
  • It protects uptime — properly coordinated devices turn a fault into a tripped branch breaker instead of a dark building.

The Design-Build Advantage

The firm that runs the study can fix what it finds

Most study providers hand you a report and leave. Our engineering team builds the model and runs the analysis, and because we also hold Arizona ROC CR-11 Electrical license #276948 and our KA Dual Engineering license #312437, the same firm can then self-perform the corrections: dialing in breaker settings, replacing underrated or obsolete gear, and re-labeling the equipment when the work is done. One contract, one accountable team, from finding to fix.

Back to Electrical Engineering
  • Field data collected by working electricians, not just engineers
  • Breaker and relay settings adjusted in-house under CR-11
  • Gear replacement priced and self-performed by the same firm
  • Tucson-based crews, statewide reach across Arizona

Electrical Load Studies

Metered load studies for service upgrades & additions

Before a facility adds load — a bigger panel, new process equipment, EV charging — someone has to prove the existing service can carry it. A metered load study answers that question with recorded data instead of nameplate guesses, and it is often the difference between reusing the service you have and paying for one you don't need.

The NEC 220.87 thirty-day method

For an existing building, the National Electrical Code offers a path past re-deriving the entire service calculation: NEC 220.87 permits the actual maximum demand — taken from a full year of demand records, or from a recording meter deployed on the service for at least 30 days — to stand in for the calculated load. Take that recorded peak at 125 percent, add the proposed new load, and if the total still fits inside the service rating, the addition is supportable on paper a plan reviewer will accept.

The 30-day method carries a caveat that matters more in Tucson than almost anywhere else: the recording has to capture, or be corrected to, the highest season of use. Here that peak is a summer afternoon with every ton of cooling running flat-out against a 110°-plus design day, not a mild February week. So we either meter through the cooling season, pull a year of demand history for the account, or apply the seasonal correction the code requires — and the report states plainly which basis it used.

When the utility asks for load data

Tucson Electric Power and Trico ask for connected and demand load information when a service is upgraded, a transformer is sized, or metering changes — and an application backed by recorded interval data moves through utility review faster than one backed by estimates. We build to TEP service standards on distribution work across town, so the study lands formatted the way utility review expects to see it.

The same data de-risks the project itself. If the study shows spare capacity, an electrical panel upgrade or an EV charging addition can proceed on the existing service — no utility service upgrade, no new transformer, no long equipment lead times. If it doesn't, you find out before the gear is ordered, while the fix is still a design decision instead of a change order.

Load study deliverables

  • Interval demand data — kW and amperage recorded across the deployment, delivered as both the raw data and readable charts.
  • Demand profile — when the facility peaks, what drives the peak, and how weekdays, weekends, and the cooling season compare.
  • Spare-capacity conclusion — the recorded maximum at 125 percent against the service rating, per NEC 220.87, with the margin available for new load stated in plain numbers.
  • Stamped letter when needed — when the utility or the plan reviewer wants an engineering letter behind the conclusion, our in-house engineering team produces it.

What a load study de-risks

  • Panel and service upgrades — sizing the replacement gear to measured demand instead of a worst-case calculation that overshoots.
  • EV charging additions — documenting the capacity for chargers, or the data an energy-management approach needs if capacity is tight.
  • Equipment additions — verifying a new RTU, compressor, or process line fits before it is purchased.
  • Generator and distribution planning — real demand profiles feed directly into sizing standby power and reworking distribution.

Related Capabilities

Where studies meet the build

Arc-flash and coordination studies usually surface distribution work — and we engineer and self-perform that too. See the full electrical engineering overview.

FAQ

Arc flash & load study questions, answered

What is an arc flash study?

It is an engineering analysis of your electrical system: how much fault current is available at each piece of gear, how the protective devices coordinate, and how much energy a worker would be exposed to in an arcing fault. The output is a report, a set of device settings, an updated one-line, and labels applied to the equipment.

Are we required to have one?

Employers are required to protect workers from electrical hazards, and NFPA 70E — the consensus standard used to satisfy that obligation — calls for an incident-energy analysis to determine the hazard and the PPE required. Insurers, corporate safety programs, and some authorities having jurisdiction ask for it directly. The practical answer for most facilities is yes.

How often does a study need to be updated?

Common practice under NFPA 70E is a review on a defined cycle, frequently every five years, and any time the system changes materially — a new service, new gear, an added generator, or a change on the utility side. If your labels predate your last upgrade, they no longer describe your system.

Do you install the labels?

Yes. We print the labels the analysis produces and apply them to the equipment they describe, so there is no gap between the study and the gear a worker is standing in front of. Our field guide explains how to read an arc flash label.

Do you need information from TEP?

Yes — the available fault current at the service. We request it from Tucson Electric Power or Trico as part of the study. Without utility source data, the model rests on assumptions the results cannot support.

Can you correct the problems the study finds?

That's the difference between us and a consulting-only firm. We self-perform the corrections under our CR-11 electrical license — settings changes, device replacements, gear and panel work, and relabeling — and document the before-and-after.

When is a load study required?

Whenever new load is proposed on an existing service and nobody can prove the capacity is there. NEC 220.87 lets recorded maximum demand stand in for a full service calculation, so a metered study is the usual path when a facility adds a panel, new equipment, or EV charging and the original service calc is long gone. TEP and Trico can also ask for load data on service and metering applications, and plan reviewers increasingly want the numbers attached to the permit.

How long does a load study take?

Typically a 30-day meter deployment plus engineering time. The code sets the 30-day minimum for recorded data, and in Tucson we time or correct the metering so the summer cooling peak is represented — a service metered only in the mild months understates its real maximum. When a full year of utility demand history is available for the account, we can sometimes skip the deployment and move straight to the analysis.

What does a load study cost?

It depends on the metering scope and what the conclusion has to support. The drivers are the number of metering points, how accessible the gear is and the safety measures required to connect recorders, whether the study covers a single panel or the whole service, and whether the finding needs a stamped engineering letter for the utility or plan review. Tell us the service size and what you plan to add, and we'll scope it — request a bid and we'll return a number.

Is your arc-flash study current?

If your labels are more than five years old — or your system has changed since they were printed — it's time. Call (520) 308-6235 or send us the facility details and we'll scope the study.

Request a Bid