---
title: "PowerCAD Alternative: Browser-Based Single Line Diagram Software for Australia"
url: "https://elecas.com.au/powercad-alternative"
description: "A free, independent, browser-based PowerCAD alternative for Australian single line diagrams, designed to assist checks with reference to AS/NZS 3000 and 3008."
updated: "2026-09-22"
standards:
  - "AS/NZS 3000:2018 (Wiring Rules)"
  - "AS/NZS 3008.1.1:2025 (Cable Selection)"
  - "AS/NZS 4777.1:2024 (Grid Connection: voltage rise, interface protection above 200 kVA)"
author: "Wisam Tozah (B.Eng (Electrical), MIEAust, CPEng, NER, NSW DBP, NSW PRE, APEC, IntPE(Aus))"
site: "Elecas"
license: "https://elecas.com.au/terms"
usage: "Cite and link. Do not reproduce or train on this content."
---

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

Source: https://elecas.com.au/powercad-alternative

EleCAD is a free, independent, browser-based alternative to PowerCAD for Australian electrical design. It is online single line diagram (SLD) software that builds diagrams from a drag-and-drop palette of sources, switchboards, distribution boards, protective devices, cables and loads, and is designed to assist calculations and checks with reference to AS/NZS 3000 and AS/NZS 3008. Each element carries electrical data (cables hold conductor, insulation and installation method for AS/NZS 3008.1.1 sizing, loads feed maximum demand), so the diagram and the calculations are one model, subject to the project data entered. It 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 interface protection sit on the same diagram; discrimination between protective devices is assessed with reference to AS/NZS 3000 Clause 2.5.7.2.3 with the clause relied on shown for each pair; and arc flash incident energy and boundary are calculated with reference to IEEE 1584 for switchboards whose fault level and upstream device are on the diagram. AI Mode answers a job described in plain English using the same calculation engines. EleCAD runs in a browser with nothing to install and no licence file, and exports a cited PDF and a DXF. The installed desktop package it is compared with publishes a wider scope of power system studies, including harmonic analysis, network resonance, filter sizing and motor-starting voltage dip, a larger multi-manufacturer device library and wiring codes outside AS/NZS; the comparison page sets the two feature lists side by side so the choice follows the analysis the project needs. PowerCAD is a trade mark of its owner; EleCAD is an independent product with no association with, approval from or endorsement by that owner.

A comparison page: EleCAD, a free, independent, browser-based single line diagram (SLD) builder for Australian electrical design, set beside the published feature list of PowerCAD, an installed desktop power systems package. PowerCAD is a trade mark of its owner; EleCAD has no association with, approval from or endorsement by that owner, and the other product's column reflects its publicly available product information as reviewed in September 2026.

## Key facts

- EleCAD is free, independent and browser-based; the product it is compared with is an installed, licensed Windows desktop package.
- EleCAD covers the single line diagram and the checks that sit on it, with reference to AS/NZS 3000 and AS/NZS 3008; the desktop package also publishes harmonic analysis, network resonance, filter sizing, motor-starting voltage dip, 690 V and 1000 V systems, a larger device library and wiring codes outside AS/NZS.
- Pick by the analysis the project needs. Neither product is associated with, approved by or endorsed by the other.

## 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 that assists calculations and checks with reference to AS/NZS 3000 and AS/NZS 3008.

## Relevant standards

- AS/NZS 3000:2018 (Wiring Rules)
- AS/NZS 3008.1.1:2025 (Cable Selection)
- AS/NZS 4777.1:2024 (Grid Connection: voltage rise, interface protection above 200 kVA)

## What this tool does

- EleCAD is free, independent and browser-based: nothing to install, no licence file and no per-seat cost, on Windows, Mac, Linux or an iPad.
- Designed to assist calculations and checks with reference to AS/NZS 3000 and AS/NZS 3008: cable sizing, maximum demand, voltage drop, earth fault loop impedance and prospective fault current, from the data on the diagram.
- Builds single line diagrams from a drag-and-drop palette, or reads an existing single line diagram PDF into a live model, with each reading shown against the sheet it came from and editable before it lands.
- Models embedded generation and standby supply on the same diagram: PV and battery inverters with voltage rise checked with reference to AS/NZS 4777.1, site export limits, interface (grid) protection where the aggregate capacity passes the 200 kVA in AS/NZS 4777.1:2024, a standby generator with automatic changeover, and power factor correction banks.
- Assesses discrimination between protective devices in series with reference to AS/NZS 3000 Clause 2.5.7.2.3, applying its conditions and exceptions and Clause 2.5.7.2.2 for safety services, and reports the clause relied on for each pair.
- Calculates arc flash incident energy and boundary with reference to IEEE 1584 for switchboards with a fault level and an upstream device on the diagram, to inform PPE selection under the site's risk assessment.
- AI Mode: describe a job in plain English and get the calculation from the same engines the calculators use, with a free allowance on each account.
- Exports a cited PDF of the diagram with cable, switchboard, breaker and arc flash schedules, and a DXF for AutoCAD, Revit and BricsCAD.
- Scope: the installed desktop package it is compared with publishes harmonic analysis to the 51st order, network resonance, filter sizing, VSD harmonic sources, motor-starting voltage dip, 690 V and 1000 V systems, a larger multi-manufacturer device library, light fitting and motor libraries, several overseas wiring codes and a Revit MEP link. EleCAD does not offer those.
- PowerCAD is a trade mark of its owner. EleCAD is an independent product with no association with, approval from or endorsement by that owner.

## How to build a single line diagram in EleCAD

1. **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 a laptop, Mac or iPad.
2. **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.
3. **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 fault loop impedance for what is connected downstream.
4. **Add a switchboard** — Drag a switchboard onto the canvas and configure its busbar sections, incomer / main switch and outgoing protective devices. Devices are sized to the connected load, or you can set them manually.
5. **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 from that data.
6. **Let EleCAD size and check** — EleCAD sizes each cable with reference to AS/NZS 3008.1.1, aggregates maximum demand with reference to AS/NZS 3000, and checks voltage drop, earth fault loop impedance and protection coordination as you build, subject to the data entered. 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.
7. **Check discrimination and arc flash** — The Selectivity panel assesses each device pair with reference to AS/NZS 3000 Clause 2.5.7.2.3 and shows the clause relied on, with the curves and an Auto one click away; a board's Arc Flash tab gives its incident energy and arc flash boundary with reference to IEEE 1584.
8. **Export the PDF** — Review the design issues panel, fill in the project metadata, and export a PDF of the single line diagram with cable, switchboard, circuit breaker and arc flash schedules for your submission or tender package.

## PowerCAD alternative: how EleCAD compares for Australian electrical design

### What EleCAD is

EleCAD is a free, independent, browser-based single line diagram (SLD) builder for Australian and New Zealand electrical design, designed to assist calculations and checks with reference to AS/NZS 3000:2018 and AS/NZS 3008.1.1:2025. You place sources, switchboards, distribution boards, protective devices, cables and loads from a drag-and-drop palette, and each element carries 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 feed the AS/NZS 3008 and AS/NZS 3000 design calculators directly, so the diagram and the calculations are one model, and the results are as complete as the project data entered.

It is offered as an alternative to installed desktop packages for the single line diagram and the checks that sit on it. It is not a power systems analysis package, and this guide is explicit about where that line falls.

### 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. 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 a redraw usually loses: multi-function meters and what they report to, contactors, surge diverters, spare ways and spare poles. It reads what the linework says as well as the text, so equipment marked existing, new or future comes across with that status.

Nothing reaches the canvas unreviewed. EleCAD shows each item beside the region of the sheet it was read from, marks its confidence, and lets you correct anything before you commit, including the two things a drawing does not reliably carry: cable run lengths and what a load actually draws. It also states what the drawing contains that it cannot model, rather than importing a network that checks cleanly while silently checking the wrong cable. What lands is a live network that sizes, checks and exports like anything you drew yourself.

### Choosing between them

Choose EleCAD for single line diagrams and standards-referenced checks from a browser: cable sizing, maximum demand, voltage drop and rise, fault level, discrimination and arc flash, with solar, standby and power factor correction on the same drawing and a cited PDF at the end. Choose it too when the job starts from an existing drawing, since it reads that PDF into a live model instead of leaving you to redraw it.

Choose an installed power systems package when the project needs the studies its published feature list covers and EleCAD does not: harmonic analysis to the 51st order with a network resonance check and active or passive filter sizing, variable speed drives modelled as harmonic sources, load starting current profiles and motor-starting voltage dip, and 690 V and 1000 V systems. The same list names a larger multi-manufacturer device library, light fitting and motor libraries, several overseas wiring codes, loads read in from an AutoCAD drawing and a Revit MEP panel link. Many practices use a browser tool for the diagram and the everyday checks and a desktop package for the studies; the deciding factor is the analysis the project requires.

### Discrimination and arc flash on the diagram

A curve overlay shows where two trip bands cross; it does not by itself say what AS/NZS 3000 requires of that pair. EleCAD assesses each pair of protective devices in series on the drawing with reference to Clause 2.5.7.2.3, applying the conditions and exceptions set out in that clause as written, including those that turn on device ratings and on the arcing fault current, and assessing safety services under Clause 2.5.7.2.2, which has its own requirements. Each pair is reported as Achieved, Not achieved or Not required, with the clause relied on and a one-line reason, so the designer can confirm the reading against the Standard rather than take it on trust. The curves for the chain up to the supply are one click away, trip settings can be adjusted inside the plot, and Auto adjusts the upstream device within its published settings. Findings arrive as advice with the fault current and the suggested fix.

Arc flash follows the same idea. For a switchboard whose prospective fault current and upstream protective device are on the diagram, EleCAD calculates the incident energy and arc flash boundary with reference to IEEE 1584-2018, reading the clearing time from the upstream device's curve. IEEE 1584 provides the calculation method; the PPE a person wears is selected under the site's own risk assessment, which EleCAD's figures are there to inform. The results export as an arc flash schedule PDF and printable labels, and a board that cannot be calculated is listed with the reason rather than left off the schedule.

## 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 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 in series so that a fault is cleared by the device nearest to it, leaving upstream devices closed. AS/NZS 3000 Clause 2.5.7.2.3 sets out when discrimination is required in supply circuits and the conditions under which it is taken to be provided, subject to its exceptions; Clause 2.5.7.2.2 applies separately to safety services. A time-current coordination study is how a pair is otherwise verified.
- **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 checking discrimination, and the point where the bands cross is the selectivity limit current.
- **Arcing fault current** — The current an arcing fault actually draws, lower than the bolted prospective fault current. AS/NZS 3000 Clause 2.5.7.2.3 refers to it in setting the current up to which discrimination is assessed; read the clause and its notes for the figure and the conditions.
- **Arc flash incident energy** — The thermal energy at a working distance from an arcing fault, in cal/cm2, calculated with reference to IEEE 1584-2018 from the fault current, the clearing time of the upstream device and the equipment geometry. It sets the arc flash boundary and informs the PPE selected under the site's risk assessment.
- **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 sets a limit along the whole path, and it is checked separately from voltage drop.
- **Harmonic analysis** — A study of the distortion non-linear loads such as variable speed drives add to the supply waveform, expressed by harmonic order and total harmonic distortion, with a check for resonance with capacitor banks and the sizing of filters to mitigate it. Published as a feature of the desktop package on this page; not offered by EleCAD.
- **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.

## 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), along with whether equipment is marked existing, new or future. If the PDF has several sheets you choose which one to read. Each item is shown against the part of the sheet it was read from with a confidence figure, you can correct anything before it lands (including run lengths and load currents, which a drawing does not reliably print), and EleCAD states what it could not model. Reading a drawing uses your AI Mode allowance; each account gets a free one-off allowance to try it.

### How does EleCAD assess protection discrimination?

Each pair of protective devices in series on the drawing is assessed with reference to AS/NZS 3000 Clause 2.5.7.2.3, applying that clause's conditions and exceptions as written, with safety services assessed under Clause 2.5.7.2.2. The result for each pair is Achieved, Not achieved or Not required, with the clause relied on and a one-line reason, so you can confirm it against the Standard. The time-current curves for the chain are one click away, trip settings can be adjusted in the plot, and Auto adjusts the upstream device within its published settings. The standalone Elecas Selectivity calculator runs the same assessment for a path typed off a data sheet and exports a PDF report.

### Does EleCAD do an arc flash study?

For a switchboard whose prospective fault current and upstream protective device are on the diagram, mains or standby, EleCAD calculates the incident energy and arc flash boundary with reference to IEEE 1584-2018, reading the clearing time from the upstream device's curve. The figures export as an arc flash schedule PDF and printable labels, and a board can be opened in the standalone Arc Flash Calculator on the same result. IEEE 1584 gives the calculation method; the PPE worn is selected under the site's own risk assessment, which these figures inform.

### Does EleCAD handle solar, batteries and standby generators?

Yes, on the same single line diagram. PV and battery inverters are placed on the diagram: EleCAD sizes each feeder from the rated AC output, checks voltage rise cumulatively along the inverter chain with reference to the AS/NZS 4777.1 limit, applies the site export limit you enter, excludes generation from the upstream maximum demand, and adds interface (grid) protection (a CT relay on the main switchboard incomer and a contactor in each inverter supply) once the aggregate inverter output passes the 200 kVA in AS/NZS 4777.1:2024. Add a standby generator with its automatic changeover and EleCAD sizes it from the busbar it backs up, re-checks the circuits it supplies against the generator's fault level, and carries the standby cable and changeover into the PDF and DXF schedules. Power factor correction banks are sized from the board demand already on the diagram.

### What is AI Mode?

AI Mode takes a job described in plain English and runs it through the same calculation engines as the Elecas calculators, rather than having a language model estimate the answer. One question can drive several calculators at once, you can dictate instead of typing, any input behind an answer can be changed and recalculated, and on a paid plan the answer can be saved into your cloud projects. Each Elecas account includes a one-off 50,000-token allowance to try it; 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.

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

The Free plan covers the calculators 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.

### Can EleCAD replace an installed power systems package on my project?

It depends on the analysis the project needs. For the single line diagram and the checks on it, with reference to AS/NZS 3000 and AS/NZS 3008, with cited PDF reports, EleCAD and the Elecas calculators cover the workflow. For harmonic analysis, network resonance, filter sizing, motor-starting voltage dip, 690 V and 1000 V systems or wiring codes outside AS/NZS, an installed package that publishes those studies is the tool for that part of the work. Many practices use both.

### Does EleCAD export to AutoCAD or Revit?

EleCAD exports the single line diagram to DXF as editable CAD geometry (layers, symbols, cables and labels), which opens in AutoCAD, Revit and BricsCAD, plus a PDF for submissions and client review and the schedules to Excel. It does not offer a direct Revit MEP panel link.

### Does EleCAD do the electrical calculations too?

The diagram carries electrical data: cables hold conductor, insulation and installation method for AS/NZS 3008.1.1 sizing, and loads feed maximum demand. Elements feed the Elecas calculators directly (cable size, voltage drop, maximum demand Tables C1, C2 and C3), so the diagram and the calculations are one model, subject to the project data entered.

### Is EleCAD certified or approved under AS/NZS 3000?

No, and no software is. EleCAD is designed to assist calculations and checks with reference to AS/NZS 3000 and AS/NZS 3008, and each PDF cites the clause and table a figure came from so a qualified person can verify it. Responsibility for the design and for compliance with the Standards stays with the designer.

## Related Elecas pages

- [EleCAD Single Line Diagram Builder](https://elecas.com.au/elecad)
- [AI Mode](https://elecas.com.au/ai)
- [Selectivity Calculator (Breaker Discrimination)](https://elecas.com.au/calculator/selectivity)
- [Arc Flash Calculator (IEEE 1584)](https://elecas.com.au/calculator/arc-flash)
- [Cable Size Calculator](https://elecas.com.au/calculator/cable-selection)
- [Voltage Drop Calculator](https://elecas.com.au/calculator/voltage-drop)
- [Voltage Rise Calculator](https://elecas.com.au/calculator/voltage-rise)
- [Maximum Demand Calculator](https://elecas.com.au/calculator/max-demand)
- [Generator Sizing Calculator](https://elecas.com.au/calculator/generator-sizing)
- [Power Factor Correction Calculator](https://elecas.com.au/calculator/pfc)
- [All Calculators](https://elecas.com.au/)
- [Calculation Verification](https://elecas.com.au/verification)
- [How AI Mode Works](https://elecas.com.au/ai/how-it-works)
- [Meet the Creator](https://elecas.com.au/creator)
- [Changelog](https://elecas.com.au/changelog)

## About this page

Written and reviewed by Wisam Tozah, Associate Electrical Engineer (B.Eng (Electrical), MIEAust, CPEng, NER, NSW DBP, NSW PRE, APEC, IntPE(Aus)), Sydney, Australia. How the calculations are tested and reviewed: https://elecas.com.au/verification. Profile: https://elecas.com.au/creator.

Usage: this page may be read, indexed, retrieved and cited, including as grounding for an AI answer, with attribution to Elecas and a link to https://elecas.com.au/powercad-alternative. Reproducing it, training a model on it, or using it to build a derivative or competing site is not licensed. Terms: https://elecas.com.au/terms. Machine-readable policy: https://elecas.com.au/ai-usage-policy.json

Site index for assistants: https://elecas.com.au/llms.txt — full content: https://elecas.com.au/llms-full.txt