The deliverable
One package. Ready for your AHJ.
A permit set delivers all of it: the determination page, the full load analysis, the rebuilt single-line, panel schedules, the assumptions sheet, and the data record. Sealed and ready to submit.
Download a finished study
A worked Measured Load Study, all seven sections, seal included. The facility is one we made up. Everything else is how a report is actually built.
One email, the PDF attached.
Determination · sheet 1 of 24 · read this page first
The service supports the addition.
Proposed new load
+96.0 kVA
Existing demand · measured
289.4 kVA
Per NEC 220.87 · × 125%
361.8 kVA
Headroom after addition
207.3 kVA
Verdict · supports the additionMethod · NEC 220.87, measured demand
Reviewed and sealed by a licensed Professional Engineer · Sep 2, 2026
Marina Logistics · Panel A additionWattif · WTF-2417 · SHT E-000
01
The determination page
- The answer up front: proposed load, existing demand, headroom, verdict.
- Supports the addition, or does not, with the gap quantified.
- The method cited: NEC 220 or 220.87.
- Seal, licence number and date on the same page.
Load calculation · NEC 220.87 · existing facility method
| 1 | Maximum demand, 12-month utility record | 289.4 kVA |
| 2 | Per NEC 220.87(1) · line 1 × 125% | 361.8 kVA |
| 3 | Proposed new load · 6 × EV chargers, 11.5 kW ea. | + 96.0 kVA |
| 4 | Total computed load · line 2 + line 3 | 457.8 kVA |
| 5 | Service capacity · 800 A @ 480 V 3Ø | 665.1 kVA |
| 6 | Spare capacity after addition · line 5 − line 4 | 207.3 kVA |
Determination · passService adequate per NEC 220.87
Demand record: utility interval data, Jun 2025 to May 2026, 15-minute intervals, peak coincident with summer cooling season. Full record appended as Exhibit B.
Marina Logistics · Panel A additionWattif · WTF-2417 · SHT E-301
02
The load analysis
- The NEC 220 and 220.87 math, line by line, nothing hidden.
- The demand record, the 125% factor, the proposed load, the spare capacity that remains.
- The determination boxed, source data appended as an exhibit.
- Your consultant, your utility and your AHJ can each check the work.
- For Measured and Metered, the data qualified: period, continuity, seasonal coverage, solar accounting, exclusions.
03
Single-line diagram
- Rebuilt from your photos and drawings, verified against what is actually in the panel.
- Service entrance, main breaker, every feeder and transformer, with frame and trip sizes noted.
- The first sheet your AHJ and your electrician read.
- It stays current as your model, so the next report starts from work already done.
Panel schedule · Panel A · 225 A MLO · 480/277 V · 3Ø 4W · 42 ckt
| Ckt | Load served | Bkr | VA | VA | Bkr | Load served | Ckt |
|---|---|---|---|---|---|---|---|
| 1 | Lighting · whse high bay | 20/1 | 1,840 | 2,210 | 20/1 | Lighting · office | 2 |
| 3 | Lighting · whse high bay | 20/1 | 1,840 | 1,660 | 20/1 | Lighting · exterior | 4 |
| 5 | Recept · dock office | 20/1 | 1,440 | 1,440 | 20/1 | Recept · break room | 6 |
| 7 | Conveyor ctrl pnl | 30/3 | 4,150 | 6,230 | 40/3 | Dock leveler 1 | 8 |
| 13 | Battery charger · forklift | 60/3 | 9,980 | 9,980 | 60/3 | Battery charger · forklift | 14 |
| 19 | Air compressor C-1 | 50/3 | 8,300 | 2,760 | 20/1 | Recept · maint shop | 20 |
| 21 | — | — | — | 1,440 | 20/1 | Recept · maint shop | 22 |
| 23 | — | — | — | 4,980 | 30/2 | Unit heater UH-1 | 24 |
| 25 | EV charger · proposed | 40/2 | 7,680 | — | — | Space | 26 |
| 29 | Spare | 20/1 | — | — | — | Space | 30 |
Connected · 64.2 kVADemand · 51.4 kVA
Marina Logistics · Panel A additionWattif · WTF-2417 · SHT E-201
04
Panel schedules
- Every circuit exactly as found in the field: load served, breaker rating, VA.
- Proposed additions drawn in place, in orange.
- Before and after on one sheet.
- Totals reconcile to the load calculation, to the digit.
Assumptions and basis · what we took from where
| Main breaker 800AT / 800AF, 65 kAIC | Field photo |
| Feeder conductor sizes, MDP to Panel A | Drawing E-101, 2016 |
| RTU-1 / RTU-2 nameplate ratings | Field photo |
| Conveyor control panel load | Stated by owner |
| T-1 transformer impedance | Typical, unverified |
| No PV or storage on site | Stated, confirmed by photo |
Anything unverified is marked here, and the determination does not lean on it.
Marina Logistics · Panel A additionWattif · WTF-2417 · SHT E-401
05
Assumptions and basis
- What came from photos, what from drawings, what was stated to us.
- Anything unverified is marked on the page, not buried.
- The reviewing engineer's checklist, made visible.
- This sheet is why the package holds up under questioning.
Appendix · the data record · exhibits A to B
Exhibit A · demand record
Jun 2025 to May 2026 · 15-minute intervals · continuity 99.2% · summer peak season covered · no PV netting applied · no exclusions.
Exhibit B · photo index
Marina Logistics · Panel A additionWattif · WTF-2417 · SHT E-501
06
The appendix
- The utility data summary, or the full 30-day measurement record.
- The record qualified: period covered, continuity, seasonal coverage, solar accounting, exclusions.
- A photo index: every image the study relied on, catalogued.
- Your consultant can retrace every number to its source.
Engineer's certification
I hereby certify that this load study, the attached single-line diagram, panel schedules, and calculations were prepared under my direct supervision, and that to the best of my knowledge they comply with NEC 220 and the applicable codes of the authority having jurisdiction.
Signature
Date · Sep 2, 2026
Licence expiry
Marina Logistics · Panel A additionWattif · WTF-2417 · SHT E-001
07
The P.E. certification
- A named, licensed Professional Engineer reviews and certifies the whole package.
- Seal, signature, date and licence number on the page.
- This is what makes the package submittable.
- Who is responsible for this number? Answered.