Can EleCAD import an existing single line diagram?

Yes. Upload a single line diagram as a PDF and EleCAD reads it onto the canvas: the incoming supply, switchboards with their busbar sections and ties, cables with conductor, insulation and installation details, protective devices, and the inline gear a redraw usually loses (multi-function meters, contactors, surge diverters, spare ways and spare poles). It also carries across whether equipment is marked existing, new or future. If the PDF has several sheets you choose which one to read. Nothing lands on the canvas until you have reviewed it: each item is shown against the part of the sheet it was read from with a confidence figure, you can correct anything (including run lengths and load currents, which no drawing reliably prints), and EleCAD states plainly what the drawing contains that it cannot model yet. You can add the result beside your existing work or replace the canvas with it. Reading a drawing uses your AI Mode allowance; every account gets a free one-off allowance to try it.

Does EleCAD do protection discrimination like PowerCAD?

Yes, across two tools. EleCAD checks discrimination by rating as you build: it grades the chain from feeder circuit breaker to incomer to section device to outgoing circuit breaker, and flags a breaker on a bus that is larger than the bus device protecting it, which is the failure discrimination exists to prevent. Isolators are skipped at both ends because a switch does not trip. For the curve-based study, the ElecAS Selectivity calculator plots the time-current bands for a protection path of any length and returns total, partial or no selectivity for every adjacent pair, with the selectivity limit current Is, the governing pair named and the setting to change when a pair falls short. PowerCAD remains the stronger tool for full power-systems modelling of a complex distribution network.

Does EleCAD handle solar, batteries and standby generators?

Yes, and all of it sits on the same single line diagram rather than in a side calculation. PV and battery inverters go straight onto the diagram: EleCAD sizes each feeder from the rated AC output, checks voltage rise cumulatively along the whole inverter chain against the AS/NZS 4777.1 2% limit, applies a site export limit, excludes generation from the upstream maximum demand, and adds central grid protection (a CT relay on the main switchboard incomer and a contactor in each inverter supply) once total inverter output passes 30 kW. Standby generation is modelled too: add a set with its automatic changeover and EleCAD sizes it from the busbar it actually backs up, re-checks every circuit against the fault level the generator delivers, and carries the standby cable and changeover through to the PDF and DXF schedules. Power factor correction banks size themselves from the board demand EleCAD already knows.

What is AI Mode, and does PowerCAD have anything like it?

AI Mode lets you describe a job in plain English and get a real calculation back, run through the same engines as the ElecAS calculators rather than guessed at by a language model. One question can drive several calculators at once, you can dictate it instead of typing, you can change any input behind an answer and watch it recalculate, and on a paid plan you can save the answer straight into your cloud projects. PowerCAD, as an installed desktop package, has no equivalent. Every ElecAS account includes a one-off 50,000-token allowance so you can try AI Mode on your own jobs before deciding; Pro and AI Pro add monthly allowances.

Do I need Windows to run EleCAD?

No. EleCAD runs in Chrome, Edge, Safari or Firefox, so it works the same on Windows, macOS, Linux or an iPad, with nothing to install, no licence file and no admin rights. PowerCAD is a Windows-only desktop install, which is often the deciding factor for a Mac-based practice or for anyone who needs to open a diagram on site.

Is EleCAD really free, and what do the paid plans add?

The Free plan covers every calculator and EleCAD itself, including PDF and DXF export, with a small ElecAS line in the PDF footer and a one-off 50,000-token AI Mode allowance. A free account is needed to download a report. Pro adds cloud save and sync across devices, unlimited saved calculations, project workspaces and folders, your own logo and accent colour on reports in place of the ElecAS footer, and 500,000 AI Mode tokens a month. AI Pro is Pro with ten times the AI allowance. There is no per-seat licence file and no watermark on either plan.

Is EleCAD really a free alternative to PowerCAD?

Yes. EleCAD runs in the browser with no licence file, no install and no per-seat cost, and drawing single line diagrams is free. It suits concept SLDs, tender drawings and design documentation; PowerCAD remains the stronger fit for deep protection discrimination and graphical time-current coordination studies.

Can EleCAD replace PowerCAD on my project?

It depends on the analysis, not the project size. For single line diagrams, AS/NZS 3008 cable sizing, maximum demand and voltage drop checks with cited PDF reports, EleCAD and the ElecAS calculators cover the workflow. For detailed protection coordination, discrimination studies and full network modelling, an installed package such as PowerCAD is still the right tool.

Does EleCAD export to AutoCAD or Revit?

Yes. EleCAD exports the single line diagram to DXF as fully editable CAD geometry (layers, symbols, cables and labels), which opens directly in AutoCAD, Revit and BricsCAD, plus a clean branded PDF for submissions and client review.

Does EleCAD do the electrical calculations too?

The diagram carries real electrical data: cables hold conductor, insulation and installation method for AS/NZS 3008.1.1 sizing, and loads feed maximum demand. Elements link straight into the ElecAS calculators (cable size, voltage drop, maximum demand Tables C1, C2 and C3), so the diagram and the calculations stay in step.

Do I need to install anything or buy a licence?

No. EleCAD is browser-based: open elecas.com.au/elecad in any modern browser and start drawing. There is no licence file, no dongle and no trial expiry.

ElecAS

PowerCAD Alternative: Browser-Based Single Line Diagram Software for Australia

EleCAD is a free, user-friendly, browser-based alternative to PowerCAD for Australian electrical design. Where PowerCAD is older, desktop-only PC software with a steeper learning curve, EleCAD is a modern tool you can pick up in minutes. It is online single line diagram (SLD) software that builds AS/NZS 3000 single line diagrams from a drag-and-drop palette of sources, switchboards, distribution boards, protective devices, cables and loads. Unlike lines on a page, every element carries real electrical data (cables hold conductor, insulation and installation method for AS/NZS 3008.1.1 sizing, and loads feed maximum demand), and link straight into the AS/NZS 3000 and AS/NZS 3008 design calculators. You can also start from a drawing you already have: upload an existing single line diagram PDF and EleCAD reads its sources, boards, busbar sections and ties, cables, protective devices, meters, contactors and surge diverters into a live model you can review, correct and calculate on. PV and battery inverters, standby generators with automatic changeover, power factor correction banks and central grid protection all sit on the same diagram, and AI Mode answers a job described in plain English using the same calculation engines. Unlike a paid, installed desktop package, EleCAD runs in any browser with no licence file and exports a clean, branded PDF of the diagram. It is the practical choice for single line diagrams and design documentation on projects of any size: a bigger project simply means a bigger diagram, and EleCAD scales to it; protection grading is covered too, by the ElecAS Selectivity calculator, which plots the time-current curves for a protection path and returns total, partial or no discrimination for every pair with the selectivity limit current Is. Heavier desktop tools like PowerCAD remain suited to full power-systems modelling of a complex distribution network on more complex projects. The deciding factor is the complexity of the analysis, not the size of the project.

Overview

Looking for a PowerCAD alternative? EleCAD covers the same core ground for Australian electrical design -- single line diagrams, AS/NZS 3008 cable sizing, AS/NZS 3000 maximum demand, voltage drop, fault levels and earth fault loop impedance -- in a browser, free, with nothing to install and no licence file. It adds what PowerCAD leaves to hand calculation: PV and battery inverters on the diagram with AS/NZS 4777.1 voltage-rise checking. Where PowerCAD still leads is deep protection work: graphical time-current coordination and discrimination studies on complex projects. The deciding factor is the depth of analysis, not the size of the job.

Key facts

EleCAD is free and browser-based; PowerCAD is a paid, installed desktop package.
The deciding factor between them is the complexity of the analysis, not the size of the project.
EleCAD covers single line diagrams and AS/NZS design checks; PowerCAD remains stronger for protection discrimination and time-current coordination studies.

Who this page is for

Australian electrical engineers, designers, electricians, estimators and contractors evaluating PowerCAD or comparing electrical design software, and anyone looking for a free, no-install single line diagram tool for AS/NZS 3000 and AS/NZS 3008 design.

Relevant standards

AS/NZS 3000:2018 (Wiring Rules)
AS/NZS 3008.1.1:2025 (Cable Selection)
AS/NZS 4777.1 (Grid Connection: voltage rise)
AS/NZS 4777.2 (Inverter Requirements: grid protection)

What this tool helps with

Free, browser-based alternative to PowerCAD: no install, no licence file, no per-seat cost.
Runs on Windows, Mac, Linux or an iPad, where PowerCAD is a Windows-only desktop install.
Modern and user-friendly: learn it in minutes, where PowerCAD is older desktop software with a steeper learning curve.
Builds AS/NZS 3000 single line diagrams from a drag-and-drop palette of sources, switchboards, devices, cables and loads.
Reads an existing single line diagram PDF onto the canvas: sources, boards, busbar ties, cables, devices, meters, contactors, surge diverters and spare ways, with every reading shown against the sheet it came from and editable before it lands.
Models real electrical relationships: cables carry AS/NZS 3008 sizing data and loads feed maximum demand, not just lines on a page.
Links straight into the AS/NZS 3008 and AS/NZS 3000 design calculators, so the diagram and the calculations stay in step.
Models embedded generation end to end: PV and battery inverters, cumulative voltage rise to AS/NZS 4777.1, site export limits, and central grid protection once the site passes 30 kW.
Models standby supply and power quality: a standby generator with automatic changeover sized from the busbar it backs up, every circuit re-checked against the generator fault level, and power factor correction banks sized from board demand.
AI Mode: describe a job in plain English and get the calculation back from the same engines the calculators use, with a free allowance on every account.
Exports a clean, branded PDF of the single line diagram for tender drawings, design submissions and project files.
Exports to DXF for AutoCAD, Revit and BricsCAD as fully editable CAD geometry: hand the SLD to your drafting team without redrawing it.
Scales to projects of any size: a bigger project just means a bigger single line diagram; the deciding factor is analysis complexity, not project size.
Grades protection: the ElecAS Selectivity calculator draws the time-current curves for a protection path and returns total, partial or no discrimination for every pair, with the selectivity limit current Is.
Honest fit: PowerCAD remains stronger for full power-systems modelling of a complex distribution network - load flow, detailed fault studies and network-wide analysis - on more complex projects.

How to build a single line diagram in EleCAD

Open EleCAD in your browser: Go to EleCAD and start a new project: there is nothing to install, no licence file and no admin rights required. It runs in Chrome, Edge, Safari or Firefox on any laptop, Mac or iPad.
Or start from an existing drawing: If you already have a single line diagram as a PDF, upload it instead of drawing from scratch. EleCAD reads the supply, boards, cables, devices, meters and spare ways off the sheet, shows you where each item came from, and lets you correct the reading before it lands on the canvas.
Add a source: Drag a source (utility or substation) onto the canvas and set its rating: amps for a utility supply or kVA for a substation. EleCAD uses it to establish the fault level and earth loop impedance for everything downstream.
Add a switchboard: Drag a switchboard onto the canvas and configure its busbar sections, incomer / main switch and outgoing protective devices. Devices auto-size to the connected load, or you can set them manually.
Add loads and cables: Add motor, socket and general loads and connect them. Each cable carries conductor material, insulation, installation method and length, so it can be sized correctly.
Let EleCAD size and check: EleCAD sizes each cable to AS/NZS 3008.1.1, aggregates maximum demand to AS/NZS 3000, and checks voltage drop, earth fault loop impedance, discrimination and protection coordination live as you build. Add PV or battery inverters, a standby generator with automatic changeover or a power factor correction bank and those are sized and checked on the same diagram.
Export the branded PDF: Review the live design-issues panel, fill in the project metadata, and export a branded PDF of the single line diagram with cable and switchboard schedules for your submission or tender package.

PowerCAD alternative: how EleCAD compares for Australian electrical design

What EleCAD is (and how it differs from PowerCAD)

EleCAD is a free, browser-based single line diagram (SLD) builder for Australian and New Zealand electrical design, built to AS/NZS 3000:2018 and AS/NZS 3008.1.1:2025 conventions. You place sources, switchboards, distribution boards, protective devices, cables and loads from a drag-and-drop palette, and every element carries real electrical data: cables hold conductor material, insulation and installation method for AS/NZS 3008 sizing, switchboards track busbars and incomers, protective devices record their trip settings, and loads contribute to the upstream maximum demand. Those inputs link straight into the AS/NZS 3008 and AS/NZS 3000 design calculators, so the diagram and the calculations stay in step.

PowerCAD is an established, paid desktop power-systems package. The core difference is delivery, ease of use and depth: EleCAD is a modern, user-friendly browser tool with no install or licence file (free and quick to learn) focused on concept single line diagrams and fast design; PowerCAD is older, desktop-only PC software with a steeper learning curve, aimed at detailed, large-project power-systems modelling.

Starting from a drawing you already have

Most electrical design work does not start on a blank canvas: it starts with somebody else's single line diagram, usually a PDF of an as-built or a consultant's issue. EleCAD reads that PDF directly. You upload the drawing, pick the sheet you want if it has several, and EleCAD extracts the incoming supply, the switchboards and their busbar sections and ties, the cables and their conductor, insulation and installation details, the protective devices, and the inline gear that usually gets lost in a redraw: multi-function meters and what they report to, contactors, surge diverters, spare ways and spare poles. It also reads what the linework says rather than only what the text says, so equipment marked existing, new or future comes across with that status intact.

Nothing reaches the canvas unreviewed. EleCAD shows each item alongside the region of the sheet it was read from, marks its confidence, and lets you correct anything before you commit, including the two things no reader can know from a drawing: cable run lengths and what a load actually draws. It also states plainly what the drawing contains that it cannot model yet, rather than importing a network that verifies cleanly while silently checking the wrong cable. You can drop the result beside what is already on your canvas or replace it outright. What lands is not a picture of a diagram: it is a live network that sizes, checks and exports like anything you drew yourself.

PowerCAD vs EleCAD: choosing the right tool

Choose EleCAD when you want immediate, no-install single line diagrams and standards-referenced design from any laptop, free, with a clean PDF of the diagram: for concept SLDs, tender drawings and projects of any size, since a bigger project simply means a bigger diagram and EleCAD scales to it. Choose it too when the job starts from an existing drawing rather than a blank sheet, since EleCAD will read that PDF into a live model instead of leaving you to redraw it.

Protection grading is no longer the dividing line it once was. The ElecAS Selectivity calculator plots the time-current curves for a protection path of any length and returns total, partial or no discrimination for every adjacent pair, with the selectivity limit current Is and the governing pair named, for MCBs, MCCBs, ACBs and gG fuses from the Schneider and NHP catalogue or typed off a data sheet.

Choose a heavier desktop package like PowerCAD when the project needs full power-systems modelling of a complex distribution network: load flow, detailed fault-level studies, motor starting and network-wide analysis. The deciding factor is the complexity of the analysis, not the size of the project: EleCAD does not try to replace that class of tool, and many engineers use EleCAD for everyday design across projects of every size and reach for a desktop package only when the analysis genuinely requires it.

Key terms

Single line diagram (SLD): A one-line schematic of an electrical distribution system showing sources, switchboards, protective devices, cables and loads. Also called a one-line diagram. It is the primary design document for an electrical installation.
Calculation model: A diagram in which each element carries real electrical data rather than being a symbol on a page, so cable sizes, demand and fault levels are derived from the drawing instead of maintained separately alongside it.
Protection discrimination (selectivity): Arranging protective devices so that a fault is cleared by the device closest to it, leaving upstream devices closed. Verifying it across a whole system is the work a time-current coordination study does.
Time-current curve (TCC): A log-log plot of a protective device's operating time against current. Overlaying the curves of upstream and downstream devices is the graphical method for proving discrimination.
Earth fault loop impedance (Zs): The total impedance of the earth fault current path. It determines the fault current and therefore whether the protective device disconnects within the time AS/NZS 3000 requires.
Prospective short-circuit current: The fault current available at a point in the installation. It sets the minimum breaking capacity of the devices there, and its minimum value governs whether protection will operate on a remote fault.
Voltage rise: The increase in voltage at an inverter's terminals above the point of supply when exporting. AS/NZS 4777.1 caps it at 2% of nominal along the whole path, and it is checked separately from voltage drop.
DXF export: A CAD interchange format that keeps the drawing editable in AutoCAD, Revit or BricsCAD, as distinct from a PDF, which fixes the drawing as published output.

Reviewed by

Wisam Tozah: Associate Electrical Engineer. B.Eng (Electrical), MIEAust, CPEng, NER, NSW DBP, NSW PRE, APEC, IntPE(Aus). See how these calculations are verified. LinkedIn. Updated 8 September 2026.

Frequently asked questions

Can EleCAD import an existing single line diagram?: Yes. Upload a single line diagram as a PDF and EleCAD reads it onto the canvas: the incoming supply, switchboards with their busbar sections and ties, cables with conductor, insulation and installation details, protective devices, and the inline gear a redraw usually loses (multi-function meters, contactors, surge diverters, spare ways and spare poles). It also carries across whether equipment is marked existing, new or future. If the PDF has several sheets you choose which one to read. Nothing lands on the canvas until you have reviewed it: each item is shown against the part of the sheet it was read from with a confidence figure, you can correct anything (including run lengths and load currents, which no drawing reliably prints), and EleCAD states plainly what the drawing contains that it cannot model yet. You can add the result beside your existing work or replace the canvas with it. Reading a drawing uses your AI Mode allowance; every account gets a free one-off allowance to try it.
Does EleCAD do protection discrimination like PowerCAD?: Yes, across two tools. EleCAD checks discrimination by rating as you build: it grades the chain from feeder circuit breaker to incomer to section device to outgoing circuit breaker, and flags a breaker on a bus that is larger than the bus device protecting it, which is the failure discrimination exists to prevent. Isolators are skipped at both ends because a switch does not trip. For the curve-based study, the ElecAS Selectivity calculator plots the time-current bands for a protection path of any length and returns total, partial or no selectivity for every adjacent pair, with the selectivity limit current Is, the governing pair named and the setting to change when a pair falls short. PowerCAD remains the stronger tool for full power-systems modelling of a complex distribution network.
Does EleCAD handle solar, batteries and standby generators?: Yes, and all of it sits on the same single line diagram rather than in a side calculation. PV and battery inverters go straight onto the diagram: EleCAD sizes each feeder from the rated AC output, checks voltage rise cumulatively along the whole inverter chain against the AS/NZS 4777.1 2% limit, applies a site export limit, excludes generation from the upstream maximum demand, and adds central grid protection (a CT relay on the main switchboard incomer and a contactor in each inverter supply) once total inverter output passes 30 kW. Standby generation is modelled too: add a set with its automatic changeover and EleCAD sizes it from the busbar it actually backs up, re-checks every circuit against the fault level the generator delivers, and carries the standby cable and changeover through to the PDF and DXF schedules. Power factor correction banks size themselves from the board demand EleCAD already knows.
What is AI Mode, and does PowerCAD have anything like it?: AI Mode lets you describe a job in plain English and get a real calculation back, run through the same engines as the ElecAS calculators rather than guessed at by a language model. One question can drive several calculators at once, you can dictate it instead of typing, you can change any input behind an answer and watch it recalculate, and on a paid plan you can save the answer straight into your cloud projects. PowerCAD, as an installed desktop package, has no equivalent. Every ElecAS account includes a one-off 50,000-token allowance so you can try AI Mode on your own jobs before deciding; Pro and AI Pro add monthly allowances.
Do I need Windows to run EleCAD?: No. EleCAD runs in Chrome, Edge, Safari or Firefox, so it works the same on Windows, macOS, Linux or an iPad, with nothing to install, no licence file and no admin rights. PowerCAD is a Windows-only desktop install, which is often the deciding factor for a Mac-based practice or for anyone who needs to open a diagram on site.
Is EleCAD really free, and what do the paid plans add?: The Free plan covers every calculator and EleCAD itself, including PDF and DXF export, with a small ElecAS line in the PDF footer and a one-off 50,000-token AI Mode allowance. A free account is needed to download a report. Pro adds cloud save and sync across devices, unlimited saved calculations, project workspaces and folders, your own logo and accent colour on reports in place of the ElecAS footer, and 500,000 AI Mode tokens a month. AI Pro is Pro with ten times the AI allowance. There is no per-seat licence file and no watermark on either plan.
Is EleCAD really a free alternative to PowerCAD?: Yes. EleCAD runs in the browser with no licence file, no install and no per-seat cost, and drawing single line diagrams is free. It suits concept SLDs, tender drawings and design documentation; PowerCAD remains the stronger fit for deep protection discrimination and graphical time-current coordination studies.
Can EleCAD replace PowerCAD on my project?: It depends on the analysis, not the project size. For single line diagrams, AS/NZS 3008 cable sizing, maximum demand and voltage drop checks with cited PDF reports, EleCAD and the ElecAS calculators cover the workflow. For detailed protection coordination, discrimination studies and full network modelling, an installed package such as PowerCAD is still the right tool.
Does EleCAD export to AutoCAD or Revit?: Yes. EleCAD exports the single line diagram to DXF as fully editable CAD geometry (layers, symbols, cables and labels), which opens directly in AutoCAD, Revit and BricsCAD, plus a clean branded PDF for submissions and client review.
Does EleCAD do the electrical calculations too?: The diagram carries real electrical data: cables hold conductor, insulation and installation method for AS/NZS 3008.1.1 sizing, and loads feed maximum demand. Elements link straight into the ElecAS calculators (cable size, voltage drop, maximum demand Tables C1, C2 and C3), so the diagram and the calculations stay in step.
Do I need to install anything or buy a licence?: No. EleCAD is browser-based: open elecas.com.au/elecad in any modern browser and start drawing. There is no licence file, no dongle and no trial expiry.