32 IEEE-conformant symbols, 6 ready templates, full pan/zoom/undo, drag-drop with snap-to-grid, multi-select rubber-band, keyboard shortcuts, mini-map. Build a complete SLD in minutes.
EEP SLD Studio is a single-page professional electrical diagram builder. No plugins, no installers, no cloud account required to use — your work is saved to your browser's local storage between sessions, and you can export to SVG (vector), PNG (HD raster), or JSON (reloadable). All math is client-side.
Symbols are organized into six categories: Sources (utility, generator, PV, wind, ATS, ATS-bypass), Distribution (transformer 2W & 3W, switchgear, MSB, MDP, panel, bus duct, junction), Protection (LV & MV breakers, fuse, disconnect, GFCI, surge protective device, relay), Loads (motor, VFD, generic load, HVAC, EV charger, lighting panel, fire pump), Renewables (PV sub-array, BESS, inverter, PFC capacitor), and Metering (kWh meter, CT, PT, ground). Each symbol carries IEEE 315 / NECA 100-conformant SVG markup that scales cleanly for permit drawings.
Pick one to skip the setup: Commercial Office (mid-rise w/ 480V service + 300 kVA stepdown), Multi-Family Residential (12 units + EV charging + house panel), Industrial Plant (4160V MV service + MCC + standby generator), Hospital (essential electrical system per NEC 517 — Life Safety + Critical + Equipment branches), Data Center (dual-source w/ STS + UPS + cooling), and Solar + Battery (500 kW PV + 250 kWh ESS).
Drag from palette to add. Click to select; Shift-click to multi-select; drag empty canvas for rubber-band selection. Wheel to zoom (focused on cursor), middle-mouse or Space+drag to pan. Del to delete, Ctrl+Z/Y to undo/redo (50-step history), Ctrl+D to duplicate, Ctrl+C/V to copy/paste, Ctrl+A to select all. Arrow keys nudge by 20 px (Shift+Arrow = 100 px). Escape to deselect and exit modes.
To your browser's localStorage under the key eep_sld_state. It persists across reloads on the same device + browser. To carry work between devices, export to JSON and re-import. Nothing leaves your browser unless you explicitly export.
This is a free advisory tool — outputs SVG/PNG/JSON but no signed PE drawing. For permit-ready output, the integrated EEP workspace embeds the SLD into your stamped project report with engineer-of-record seal + SHA-256 hash. See the dashboard.
It walks your input data (service, optional transformer, optional ATS+generator, panels, loads), builds a tree, runs a top-down BFS hierarchical layout (each generation gets its own row), and routes wires from each parent's bottom port to each child's top port through a mid-gutter horizontal segment. Output is identical to drawing it by hand from the same data.
Symbol shapes are IEEE 315 / NECA 100 — universal in both jurisdictions. NEC vs CEC code-reference text on the symbols swaps automatically via the standard pill in the topbar (if you're signed in to the app shell).