Arc Flash Study Deliverables · What You Receive

What you receive

Six deliverables, one signature discipline

Each is a separate reviewable document, not a chapter buried in an appendix. Put this list in your scope of work and you will get all six.

01

Incident energy report

Every working position calculated to IEEE 1584-2018. Arc flash boundary, approach distances and the arc-rated PPE required at each. Bus by bus, with the bolted fault current, arcing current and clearing time that produced each result. Hand verified at critical buses.

02

NFPA 70E format labels

Print ready and installed. Field by field, exactly what our label carries is set out below, because that is the part a worker reads and the part an inspector checks.

03

NFPA 70E conformance matrix

A section-by-section map from each part of the report to the clause it satisfies, at the front of the document rather than the back. An auditor should be able to verify compliance in minutes instead of hunting through appendices.

04

Reconciled single line diagram

Verified against the as-installed plant by supervised walkdown, drift logged per equipment item, and co-signed by your engineer before any calculation runs. The calculation is only as good as this document.

05

Field data pack

Nameplates, CT and PT ratios, trip unit settings, cable runs. Photographed and logged per equipment item. The basis-of-design archive that survives staff turnover and makes the next study cheaper than this one.

06

Executive summary and action register

Two pages for sign-off, then actions ranked by priority and assigned by discipline: engineering control, PPE, procedure, training. The part your EHS lead reads first and the only part most of the organisation ever sees.

Two things we hand over that are worth asking every bidder for. The native calculation model file, not just the exported PDF, so you are never locked to one consultant to make a change. And photographs of every installed label, which is how you evidence installation without walking the plant yourself.

Send your draft scope of work and we will mark it against this list, whether or not you invite us to bid.

The deliverable a worker actually reads

What must an arc flash label show under NFPA 70E

Every field on the label, and the reason it is there. A study is consumed one label at a time, by someone standing in front of a panel deciding what to wear. Section 130.5(H) sets the minimum. This is our label, field by field, against it.

Field on our label	What it is for
Incident energy in cal/cm², at a stated working distance	The number the arc-rated clothing is selected against. It is meaningless without the distance, which is why the two are printed together
Arc flash boundary	The distance at which incident energy falls to 1.2 cal/cm², the onset of a second degree burn on bare skin
Nominal system voltage	Required marking, and the value the shock boundaries are derived from
Limited approach and restricted approach	Shock boundaries, set by voltage rather than by incident energy. Routinely confused with the arc flash boundary on site
The arc-rated PPE required	Described as the ensemble to be worn · for example arc-rated shirt and trousers plus coverall plus suit, with the glove class
Equipment name	Ties the label back to a specific row in the report and a specific device in the coordination study. Without it, the label cannot be audited
Assessment date	When the analysis behind these numbers was performed. It is how anyone standing at the panel can tell whether the label still reflects the system in front of them
WARNING or DANGER header	The header itself carries information. DANGER is used where the incident energy exceeds the maximum available PPE arc rating, so the severity is legible before a single number is read

Can a label show both incident energy and a PPE category?

NFPA 70E permits the incident energy analysis method or the arc flash PPE category method for a given piece of equipment. It does not permit both on the same equipment. A label carrying a calculated cal/cm² figure and a PPE category number alongside it is using both, and that is a finding waiting to happen.

Our labels use the calculated method and describe the ensemble. There is no category number on them, and that is deliberate.

If you already hold labels from a previous study, this is the quickest thing to check. It takes a few seconds per label and it tells you a great deal about how the study was run.

VB Engineering WARNING arc flash and shock risk label reading 4.97 calories per square centimetre at 61 cm with a 1.228 metre arc flash boundary on a 415 volt board, the full arc rated PPE ensemble written out, and the assessment date — **WARNING · 4.97 cal/cm²** at 61 cm, on a 415 V board. Arc flash boundary 1.228 m. The PPE field lists the ensemble to be worn, item by item, so nobody has to interpret a category number.

VB Engineering DANGER arc flash label on a 400 kV main bus reading 345 calories per square centimetre at 182.9 cm with a 31 metre arc flash boundary, where the PPE field reads Exceeds Maximum PPE Arc Rating — **DANGER · 345.04 cal/cm²** at 182.9 cm, on a 400 kV main bus. Arc flash boundary **31.07 m**. The PPE field reads **Exceeds Max. PPE Arc Rating**.

How long must an arc flash label stay legible?

This is the requirement almost nobody sells against, and it is in force now. The 2024 edition of NFPA 70E added an explicit durability requirement to 130.5(H): a label must be of sufficient durability for the environment it is installed in. NEC 110.21(B) says the same thing about field-applied hazard markings, in its own words. Heat, UV, oil, chemical attack and washdown are all foreseeable, and a label that has faded to grey is not a label.

Two consequences worth hearing before signing anything. The standard puts the duty on the owner of the equipment, not on the consultant who calculated the numbers · documentation, installation and maintenance of the marking all sit on your side of the line once we leave. And a label emailed as artwork discharges none of it.

So we print on media rated for the area, fit the label ourselves, and photograph every installed label into the field data pack · which is what lets you evidence installation to an inspector four years later without walking the plant. It is also the honest reason to ask, at year four, whether the labels in your washdown areas are still readable.

The label that tells you not to do the work

The second label is the one worth sitting with. At 345 cal/cm² no arc rated clothing exists that protects a worker at that position. So the PPE field does not name an ensemble. It says the energy exceeds the maximum available rating, and the boundary is thirty one metres.

That label is not a PPE instruction. It is a prohibition, and the answer to it is engineering rather than clothing: a protection setting change, a maintenance mode, remote racking, or a different work method. A study that never produces a label like this at a 400 kV bus has not looked hard enough. A study that produces one and then recommends a heavier suit has not understood it.

The difference between those two labels is not the standard and not the software. It is the fault duty and the clearing time at that bus, which is why the coordination study belongs inside the same scope. Halve the clearing time and you roughly halve the incident energy · an engineering recommendation rather than a procurement one, and the thing a good report leads with. The method behind the numbers is covered on arc flash hazards.

How the deliverable is produced

Seven steps, six to eight weeks, signed at every gate

An audit trail rather than a software run. Each step ends in something a named person has put their name to.

01

Field walkdown and as-found verification

Every switchgear, motor control centre and transformer visited. Nameplates, CT and PT ratios and trip unit settings logged and photographed. Your engineer accompanies the walkdown.

2 to 3 days on site · senior engineer led

02

Single line diagram reconciliation and client sign-off

Walkdown data plotted against your drawing. Every drift logged per equipment item. Your engineer co-signs the reconciled diagram before any calculation begins. This is the input-layer discipline that decides the accuracy of every number downstream.

3 to 5 days · client co-signed

03

System modelling and short circuit calculation

Model built from verified as-found data. Source impedances, transformer parameters, cable impedances, motor contribution. Fault calculations to IEC 60909, cross-checked by hand at critical buses.

1 to 2 weeks

04

Incident energy calculation to IEEE 1584-2018

Energy at every working position, arc flash boundary, and the arc rating required. Where incident energy exceeds 40 cal/cm², the recommendation is that energised work is prohibited, documented with the engineering control alternatives rather than left as a clothing problem.

1 week · IEEE 1584-2018

05

Label production

Print-ready NFPA 70E format labels generated per equipment item, carrying the fields set out above. English, with a Spanish safe work practice insert where the workforce requires one.

2 weeks

06

Site installation and handover briefing

Labels installed at every assessed item, boundaries marked where the calculated distance requires a physical demarcation, and a workforce briefing delivered the same day so people understand the labels before energised work resumes. Sequenced around your outage window.

1 to 2 weeks · witness signed

07

Final report and signature

Conformance matrix at the front. Executive summary and action register. Drafted by a Chartered Engineer, independently cross-checked by a Principal Reviewer, and PE stamped where your specification requires it.

1 week

Two VB engineers reconciling single line diagrams against a motor control centre lineup during the field walkdown — Step 02. The reconciliation, not the software. Drift logged per equipment item and co-signed before any calculation runs.

Tell us your plant voltage and substation count and we will come back with the scoped bus count that drives all of the above.

Delivered, not just calculated

What the deliverable looks like on the floor

A study that ends at a document has not changed anything. Specify these two in your scope and you will get them.

Motor control centre cubicle bank with an arc flash warning label installed on every door — **Every door, not a sample.** A study is finished when the label a worker reads before opening a panel is on all of them.

Arc flash approach boundary marked on the floor in front of an electrical panel lineup — **Boundaries marked** where the calculated distance demands a physical demarcation, in the same visit as the labels.

Delivered in the United States

Three engagements, three deliverable shapes

Anonymised, as every engagement on this site is.

Site	What drove the scope	Outcome
Refining, Gulf Coast Distillation unit · 138 kV intake · 13.8 kV plant	An OSHA finding triggered the rebuild. Full re-coordination, recalculation to IEEE 1584-2018, and labels installed during the planned spring turnaround	Average incident energy at the motor control centre buses reduced by 41% through coordination changes. Finding closed. Crews retrained on the new boundaries
Petrochemical Polyolefins train · 230 kV switchyard · 4.16 kV process	Insurance-driven five year revalidation. Reconciliation against last-known-good drawings, with drift on three substations found and corrected	Carrier accepted the revalidation. Process safety evidence packaged. A five year retainer signed for continuous compliance rather than episodic re-tendering
Data centre Colocation · 12.47 kV utility intake · 480 V floor	Pre-commissioning study before tenant onboarding. Model built from EPC drawings then reconciled against the as-installed switchgear	Commissioning acceptance cleared. Tenant safety onboarding pack issued. PPE storage designed into the operations floor plan

Asked before award

Questions about the deliverable

What is included in an arc flash study?

Six deliverables: the incident energy report to IEEE 1584-2018, NFPA 70E format labels installed at the equipment, a conformance matrix, the single line diagram reconciled against the as-installed plant, the field data pack, and an executive summary with an action register. VB Engineering delivers all six as separate reviewable documents.

What does an arc flash study report contain, section by section?

A conformance matrix at the front, the executive summary and action register, the reconciled arc flash one line diagram, short circuit results, protective device coordination, and the incident energy results bus by bus with boundaries and required PPE. VB Engineering also includes the field data pack as an annex so the basis of design survives staff turnover.

What must an arc flash label show under NFPA 70E?

The nominal system voltage, the arc flash boundary, and one PPE determination. VB Engineering labels carry the calculated incident energy at a stated working distance, the arc flash boundary, the voltage, the limited and restricted approach distances, the arc-rated ensemble required, and the bus and protective device identifiers.

Can a label show both incident energy and a PPE category?

No. NFPA 70E permits the incident energy analysis method or the PPE category table method for a given piece of equipment, not both on the same equipment. A label carrying a calculated figure and a category number together is mixing methods. VB Engineering labels use the calculated method and describe the required ensemble.

Is the arc flash report stamped by a Professional Engineer?

Yes, where your specification or authority requires it. Every section additionally carries a named Chartered Engineer signature: the Practice Lead drafts and the Principal Reviewer independently cross-checks. Tell us at scoping, because a stamp affects the schedule.

Do I receive the calculation model file?

Yes. VB Engineering hands over the native model alongside the report, so you are never locked to one consultant to make a change. Reports are issued as software-agnostic documents with the raw model files included.

What is a conformance matrix and why is it at the front?

It maps each section of the report to the clause of the standard it satisfies. Placed at the front, an auditor verifies compliance in minutes rather than hunting through appendices. VB Engineering puts it before the executive summary on every deliverable.

How is the single line diagram verified before the calculation runs?

By supervised field walkdown. Every nameplate, CT and PT ratio and trip unit setting is checked against the drawing, drift is logged per equipment item, and your engineer co-signs the reconciled diagram before any model is built. VB Engineering treats that signature as a gate, not a formality.

What happens when incident energy exceeds 40 cal/cm²?

The recommendation is that energised work is prohibited at that position. VB Engineering documents it with engineering control alternatives · protection setting changes, maintenance mode, remote racking or a different work method · rather than treating it as a clothing problem to be solved with a heavier suit.

Are labels installed, or just supplied as files?

Installed. VB Engineering fits the label at every assessed item, marks boundaries on the floor where the calculated distance requires it, photographs each installed label, and delivers a workforce briefing the same day so people understand the labels before energised work resumes.

How long does an arc flash label have to stay readable, and who replaces it?

NFPA 70E 130.5(H) requires the label to be of sufficient durability for its environment, and NEC 110.21(B) requires the same of field-applied hazard markings. The duty to maintain the marking sits with the equipment owner, not the consultant. VB Engineering prints on media rated for the area, installs the label and photographs it, so a replacement decision at year four is evidenced rather than guessed.

Where to go next