ElecAS

EleCAD — Free Online Single Line Diagram Builder

EleCAD is a free, browser-based single line diagram (SLD) builder for Australian electrical designers, electricians, contractors and project teams. Draw and edit electrical single line diagrams online with no install, no licence file and no plug-ins — just open the browser and start placing switchboards, loads, sources, protection devices and cables. EleCAD models the real electrical relationships between components, not just lines on a page: every connection carries cable data, every switchboard tracks its busbars and incomers, every protective device records its trip settings, and every load contributes to the upstream maximum demand. The tool is built for the way Australian electrical design actually works — main switchboards and distribution boards, sub-mains and final subcircuits, three-phase and single-phase, MCBs, MCCBs, RCDs and HRC fuses, copper and aluminium conductors, V-75 and X-90 insulation. Diagrams stay live: change a downstream load and the upstream demand updates; change a cable run and the voltage drop check follows. Export to PDF for design submissions, project files and client review. EleCAD pairs natively with the rest of the ElecAS calculator suite — cable size, voltage drop, maximum demand (Tables C1, C2, C3), conduit sizing, generator sizing, UPS battery sizing — so the diagram and the calculations stay in lock-step. A practical alternative to AutoCAD Electrical, ETAP, EasyPower and SmartDraw for early-stage design, concept SLDs, tender drawings and small-to-medium project documentation.

Why this page matters

EleCAD is a free, browser-based single line diagram (SLD) builder for Australian electrical designers, electricians, contractors and project teams. Draw and edit electrical single line diagrams online with no install, no licence file and no plug-ins — just open the browser and start placing switchboards, loads, sources, protection devices and cables. EleCAD models the real electrical relationships between components, not just lines on a page: every connection carries cable data, every switchboard tracks its busbars and incomers, every protective device records its trip settings, and every load contributes to the upstream maximum demand. The tool is built for the way Australian electrical design actually works — main switchboards and distribution boards, sub-mains and final subcircuits, three-phase and single-phase, MCBs, MCCBs, RCDs and HRC fuses, copper and aluminium conductors, V-75 and X-90 insulation. Diagrams stay live: change a downstream load and the upstream demand updates; change a cable run and the voltage drop check follows. Export to PDF for design submissions, project files and client review. EleCAD pairs natively with the rest of the ElecAS calculator suite — cable size, voltage drop, maximum demand (Tables C1, C2, C3), conduit sizing, generator sizing, UPS battery sizing — so the diagram and the calculations stay in lock-step. A practical alternative to AutoCAD Electrical, ETAP, EasyPower and SmartDraw for early-stage design, concept SLDs, tender drawings and small-to-medium project documentation. This static content is published so the canonical route has meaningful crawlable HTML even before the interactive application hydrates.

Who this page is for

Australian electrical engineers, designers, electricians, contractors, estimators, building services consultants and project managers building or reviewing single line diagrams, switchboard concepts and early-stage electrical documentation.

Relevant standards

  • AS/NZS 3000:2018 (Wiring Rules)
  • AS/NZS 3008.1.1:2025 (cable sizing references)
  • Australian electrical drawing conventions

What this tool helps with

  • Free, online, browser-based — no install, no licence file, no plug-ins. Open any modern browser and start drawing.
  • Drag-and-drop palette for sources, switchboards, distribution boards, loads, motors, generators, transformers and protective devices.
  • Model real electrical relationships, not just lines — every connection carries cable data and feeds into demand and voltage-drop calculations.
  • Switchboard editor with general settings, busbar configuration, incomer / main switch settings, and outgoing device schedules.
  • Protection device library — MCB curves B / C / D, MCCB, RCD, RCBO, HRC fuses — with editable trip settings and discrimination context.
  • Cable editor with copper / aluminium, V-75 / X-90, single-phase / three-phase, length, installation method and live AS/NZS 3008 sizing checks.
  • Links directly into the ElecAS calculator suite — cable size, voltage drop, maximum demand (Tables C1, C2, C3), generator sizing, UPS battery sizing.
  • Export single line diagrams to PDF for design submissions, tender packages, client review and project documentation.
  • Tutorial mode walks first-time users through placing a source, switchboard, downstream loads and printing the diagram.
  • A practical alternative to AutoCAD Electrical, ETAP, EasyPower, SmartDraw and Lucidchart for early-stage Australian electrical design.

Reviewed by

Wisam Tozah — Associate Electrical Engineer. B.Eng (Electrical), MIEAust, CPEng, NER, NSW DBP, NSW PRE, APEC, IntPE(Aus). LinkedIn.

Frequently asked questions

What is a single line diagram?

A single line diagram (SLD), also called a one-line diagram, is a simplified schematic of an electrical power system that shows components — sources, switchboards, protective devices, cables and loads — using single lines and standard symbols instead of separate phase conductors. SLDs are the primary design and reference document for electrical installations in Australia, used for design submissions, tender drawings, switchboard schedules, commissioning and as-builts.

Is EleCAD free?

Yes — EleCAD is free to use in your browser. You can build, edit and export single line diagrams without an account for the standard workflow. Pro features (saving projects to the cloud, larger diagrams, project history) are available on a paid plan.

Does EleCAD work in the browser without installing software?

Yes. EleCAD runs entirely in the browser — Chrome, Edge, Safari and Firefox are all supported. There is nothing to download, no licence file to install, and no plug-in to enable. Diagrams are rendered locally so it works on any laptop, including locked-down corporate machines.

Can I export EleCAD single line diagrams to PDF?

Yes. EleCAD exports your single line diagram to a clean, branded PDF suitable for design submissions, tender packages, client review and project files. The PDF includes the diagram, project details and a switchboard / device schedule.

EleCAD vs AutoCAD Electrical — what is the difference?

AutoCAD Electrical is a heavyweight desktop CAD package licensed per seat — it is excellent for detailed schematics, panel layouts and large industrial projects but has a steep learning curve and high cost. EleCAD is a free, browser-based SLD builder focused on Australian single line diagrams and early-stage design — quick to learn, no install, and integrated with the ElecAS calculator suite. EleCAD is the right tool for concept SLDs, tender drawings, small-to-medium projects and any time AutoCAD would be overkill.

EleCAD vs SmartDraw or Lucidchart for single line diagrams?

SmartDraw and Lucidchart are general-purpose diagramming tools — they have electrical symbol libraries but no electrical engineering intelligence. EleCAD understands the actual electrical relationships: switchboards have busbars and incomers, cables have conductor material and installation method, loads contribute to maximum demand, protective devices have trip curves. That makes EleCAD substantially faster for real electrical design, with fewer mistakes carried into the calculations.

What symbols and components does EleCAD support?

EleCAD includes the common Australian SLD symbols: utility supply, transformer, generator, UPS, main switchboard, distribution boards, switches, isolators, MCBs, MCCBs, RCDs, RCBOs, HRC fuses, motors, lighting loads, socket loads, mechanical loads and EV charging. New symbols are added based on user requests via the Contact page.

Does EleCAD link to cable sizing and maximum demand calculations?

Yes. Every cable in EleCAD carries the inputs needed for AS/NZS 3008 cable sizing (conductor, insulation, installation method, length, design current) and every load feeds into the AS/NZS 3000 Table C1 / C2 maximum demand calculation upstream. You can jump from a diagram element straight into the relevant ElecAS calculator with the inputs prefilled.

Can I share or collaborate on diagrams?

Diagrams are exported as PDF for sharing today. Real-time multi-user collaboration is on the roadmap — sign in to your ElecAS account to be notified when it ships.

Is EleCAD suitable for AS/NZS 3000 design submissions?

EleCAD is suitable for the single line diagram component of an AS/NZS 3000 design submission, tender package or as-built drawing set. As with any electrical design tool, the user remains the engineer of record — every diagram, calculation and design decision must be reviewed and signed off by a qualified electrical professional before issue, construction or energisation. See the Verification page for the engineering review process behind ElecAS.

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