When to use: Enter data straight off an equipment nameplate — motor, transformer, pump/VFD, generator, or panel — and get a linked one-line diagram, equipment schedule, bill of materials, and wire schedule generated from it, using this studio’s existing NEC 430/450/240 conductor and OCPD sizing conventions. This generates a preliminary design package for planning and documentation purposes— final electrical design, conductor/OCPD sizing verification, and code compliance require a licensed electrician’s or engineer’s review.
This tool turns equipment nameplate data — motor, transformer, pump/VFD, generator, or panel — into a linked preliminary design package: a real SVG one-line diagram with standard symbols, an equipment/nameplate schedule, a bill of materials, and a wire schedule, all built from the same NEC 430 (motors), 450 (transformers), and 240/310.16 (OCPD/conductor) conventions already used elsewhere in this studio's calculators. Enter values manually, or (optionally, best-effort) scan a nameplate photo to pre-fill fields, then review and edit before using the package for planning.
Pick an equipment type — Motor, Pump/VFD, Transformer, Generator, or Panel/Switchgear — then enter the values stamped on the nameplate: voltage, phase, horsepower or kVA/kW, full-load current (or leave it blank to estimate it from the NEC 430.248/430.250 motor tables or the standard kVA formula), and a few type-specific fields like service factor, transformer connection type, or main breaker/bus rating. The tool immediately regenerates a one-line diagram, equipment schedule, BOM, and wire schedule from those values — there's no separate 'generate' step, every field updates the whole package live.
A one-line diagram with standard symbols (circle+M for motors, circle+G for generators, overlapping circles for transformers, a breaker symbol for the OCPD, and a ground symbol) laid out as source → OCPD → equipment-specific stage (VFD/starter, transformer, transfer switch, or panel bus) → load. An equipment/nameplate schedule summarizing the entered nameplate data alongside the sized OCPD and disconnect. A bill of materials (BOM) listing the breaker, starter/VFD/contactor, disconnect, conductor length and size, and pilot devices or grounding hardware appropriate to the equipment type. A wire schedule listing each conductor run with its NEC Table 310.16 75°C copper size and a simplified single-conductor conduit trade-size estimate. A downloadable text design summary tying it all together.
Conductor sizing uses NEC Table 310.16 75°C copper ampacity (no ambient/bundling derating), OCPD sizing uses simplified NEC 430.52 (motors, 250% of FLA), 450.3 (transformers, a 125%-of-FLA simplification), and 240.4(B)/240.6 (panels, conductor ampacity ≥ breaker rating, standard sizes) conventions — the same conventions used by this studio's Motor Branch Circuit Sizing and Wire Ampacity & Derating calculators. It does not perform a short-circuit study, protection coordination, arc-flash analysis, voltage drop check, or full NEC 220/230 service load calculation. The conduit size shown is a simplified single-conductor planning estimate, not a NEC Chapter 9 fill calculation — use the Conduit Fill Calculator for that. Photo OCR is optional, best-effort, and frequently misreads low-contrast or damaged nameplates — always verify extracted values against the physical nameplate.
Manual entry is the primary path and works completely on its own — every field is a normal editable input. The photo-scan feature is optional and best-effort: it runs OCR in your browser (via Tesseract.js, loaded on demand) and pre-fills whichever fields it can confidently read, but you should always verify the extracted values against the physical nameplate before relying on the generated package.
Leave the "Nameplate FLA" field blank and the tool estimates full-load current from NEC Table 430.248 (single-phase) or 430.250 (three-phase) using the horsepower, voltage, and phase you entered — the same table lookup used by the Motor Branch Circuit Sizing calculator.
Every type follows the same source → overcurrent protection → equipment-specific stage → load pattern used in real one-line diagrams: motors get a starter or VFD ahead of the motor symbol, transformers get primary and secondary OCPDs bracketing the transformer symbol, generators get an OCPD and transfer switch ahead of the building load, and panels show the main breaker feeding the bus, all with a grounding branch off the first breaker.
The BOM, equipment schedule, and wire schedule are recalculated live from your inputs — to change a quantity, size, or rating, adjust the corresponding nameplate field (voltage, HP/kVA, conductor length, etc.) rather than editing the table directly. You can download the SVG diagram, a PNG image, or a full text design summary and edit those downstream in your own documentation.
Try our Electrical Studio
More calculators, simulators, and guides for this discipline.