| Quick Answer: Arc flash and short-circuit coordination studies are provided by power systems engineering firms with licensed Professional Engineers, because the three studies share one system model and must be engineered together. Bowtie Engineering performs combined arc flash, short-circuit, and coordination studies for facilities nationwide, delivering IEEE 1584-based incident energy values, verified device settings, and compliant labels. Call 866-730-6620 to scope your study. |
Facility managers often shop for an “arc flash study” without realizing they are actually buying three interlocking engineering analyses: a short-circuit study, a protective device coordination study, and the arc flash incident energy calculation built on top of both. Buy them separately from different vendors and the model fragments; buy them together from one engineering firm and each analysis strengthens the others. This article explains who provides these combined studies, why they belong together, and what a complete deliverable looks like.
What Are the Three Studies, and How Do They Relate?
- Short-circuit study — calculates the maximum fault current available at every bus, confirming equipment ratings are adequate
- Coordination study — analyzes protective device settings so the breaker nearest a fault clears it first, minimizing outage spread
- Arc flash study — uses the fault current and device clearing times to calculate incident energy and required PPE per IEEE 1584
The dependency runs in one direction: arc flash results are only as accurate as the short-circuit values and clearing times feeding them. That is why a standalone arc flash quote that never mentions the other two studies should raise questions.
Why Should One Engineering Firm Perform All Three?
One firm, one model, one accountable engineer. When the same team builds the system model, verifies field data, and runs all three analyses, the coordination settings they recommend are immediately reflected in the incident energy results — often lowering hazard levels at the same time. Bowtie Engineering runs the full sequence inside every incident energy study, with licensed PEs modeling to IEEE 1584 and NFPA 70E, so facilities get coordinated protection and accurate labels from a single engagement rather than three disconnected reports.
What Does Good Coordination Actually Buy You?
Selective coordination is the difference between losing one machine and losing the whole plant. When devices are properly coordinated, the breaker closest to a fault opens first and everything upstream stays closed. Poor coordination produces nuisance trips, cascading outages, and — critically for safety — longer clearing times that multiply arc flash incident energy. Many facilities discover during their first combined study that a simple settings adjustment cuts both their outage exposure and their required PPE level at key equipment. That is engineering value no label-only vendor can deliver.
What Should the Deliverables Include?
- Field-verified one-line diagram of the distribution system
- Short-circuit results confirming equipment interrupting ratings
- Time-current coordination curves with recommended device settings
- Incident energy and arc flash boundary values for every studied bus
- ANSI-compliant arc flash labels installed on equipment
- A mitigation report where incident energy or coordination gaps demand action
Insist on seeing a sample report before hiring. The best firms show you exactly what your engineers, insurers, and auditors will receive.
When Do These Studies Need to Be Updated?
NFPA 70E requires the arc flash risk assessment to be reviewed at least every five years or after major system modifications — and because the three studies share one model, a change that touches any of them touches all of them. New utility service, added generation, switchgear replacement, or large load additions all warrant a refresh. Facilities that pair their studies with ongoing electrical maintenance and NETA-compliant testing catch these triggers early, because the same team servicing the gear knows when the model no longer matches the floor.
How Do You Evaluate a Provider for a Combined Study?
Ask three questions. First, will a licensed PE perform and stand behind all three analyses, or is any part subcontracted? Second, how is field data collected — because coordination recommendations built on assumed settings are guesses, not engineering. Third, what happens when the study finds problems: does the firm engineer solutions such as settings changes, remote operation, or equipment upgrades, or does it simply document the hazard and leave? Firms with real power systems depth welcome these questions. Bowtie Engineering has delivered programs nationwide since 2015, backed by licensed PEs and BBB accreditation since 2019.
What Problems Do Combined Studies Uncover Most Often?
Ask any engineering team what a first combined study finds at a typical facility and the answers converge on a familiar list. Breakers still carrying factory-default settings from installation day, never adjusted to the design coordination scheme. Equipment whose interrupting rating is below the fault current now available at its bus — a silent problem created years earlier by a utility service upgrade nobody modeled. Downstream devices set slower than upstream ones, guaranteeing that a small fault takes out a large area. And incident energy levels at routinely serviced equipment far above what anyone assumed, because clearing times were never actually calculated.
- Factory-default trip settings never programmed to the coordination design
- Interrupting ratings exceeded after utility or generation changes
- Miscoordination that spreads small faults into large outages
- Incident energy far above assumptions at frequently serviced gear
- Undocumented system modifications invisible on the official drawings
- Fuse and breaker replacements that quietly changed the protection scheme
What unites these findings is that none of them announce themselves during normal operation — the plant runs fine until the day it does not. That is precisely the argument for the combined study: it is the only routine engineering exercise that examines the system as a system, and it converts a list of latent failures into a prioritized correction plan while every item is still cheap.
Frequently Asked Questions
Can I get an arc flash study without a short-circuit study?
Not a credible one. Incident energy calculations require accurate fault current values, so every legitimate arc flash study includes short-circuit analysis, whether or not the proposal names it separately. If a proposal is silent on short-circuit scope, ask — the answer reveals how the study is actually built.
What is selective coordination?
Selective coordination means protective devices are set so the device nearest a fault operates first, isolating the smallest possible portion of the system and keeping the rest of the facility energized.
Do coordination changes affect arc flash results?
Yes, directly. Faster clearing times reduce incident energy, so coordination adjustments frequently lower the PPE required at specific equipment — one of the biggest practical benefits of a combined study.
How long does a combined study take?
It depends on facility size and equipment count. Field data collection is scheduled around operations, and the engineering, review, and labeling phases follow — providers can give firm timelines once the equipment scope is known. Ask for a firm timeline in the proposal once the equipment scope is set.
Does Bowtie Engineering install the labels?
Yes. Bowtie Engineering delivers accurate, compliant arc flash labels as part of its incident energy studies, along with PPE recommendations and a complete risk mitigation report.
Need help now? Call Bowtie Engineering at 866-730-6620 or request a free quote online.
Key Takeaways
- Arc flash, short-circuit, and coordination studies share one model and belong with one engineering firm
- Arc flash accuracy depends entirely on fault current values and device clearing times
- Proper coordination limits outages and often lowers incident energy at the same time
- Complete deliverables include verified one-lines, coordination curves, labels, and mitigation guidance
- NFPA 70E requires review at least every five years or after major system changes
- Scope a combined study with Bowtie Engineering — request a free quote