AutoCAD Electrical: From a blank drawing to a wiring diagram
The short answer
The order is: create a project, set the wire numbering and component tagging formats in drawing properties, insert a ladder, insert components from the catalogue so they carry a part number, draw wires on wire layers, link sheets with source and destination arrows, place child contacts against parent coils, generate the panel layout from the schematic, and only then run the reports. The reports are the point. AutoCAD Electrical is a database that happens to draw, and in plain AutoCAD you would type the bill of materials, the wire list and the terminal plan by hand and they would be out of date within a week.
Create a project, not a loose DWG
The project file lists the drawings in order and holds the settings they share: wire number format, tag format, cross-reference format, wire layers and the catalogue lookup path.
A DWG opened on its own still draws. It is simply not part of any project, so every project-wide operation skips it. A cross-reference will not find a contact on a sheet that is not listed. A retag renumbers one drawing and leaves the rest. And all three reports are project reports, generated by walking the drawing list, a drawing outside the project contributes nothing to any of them.
So: New Project, its own folder, and add drawings through the Project Manager rather than by copying files in.
Drawing properties: the two schemes to decide first
Decide these before the first symbol, because changing them later means a project-wide retag.
Wire numbering is either sequential, 1, 2, 3 across the project, simple and meaningless to the electrician tracing it, or reference-based, where the wire takes the ladder line reference it sits on, optionally prefixed with the sheet number. A wire labelled 2107 is on sheet 2, line 107. Use reference-based unless a customer standard says otherwise. IEC 60204-1 requires conductors to be identifiable; it does not pick the scheme for you, and the one that encodes a location is the one that survives commissioning.
Component tags come from a format string built from the symbol's family code and position, so a control relay coil on line 103 comes out as CR103. Family codes come from the symbol library, CR for control relays, PB for pushbuttons, LT for pilot lights, so the tag says what the device is and where it lives without anyone typing either.
Ladder first, then wires
Insert Ladder asks for the first reference number, the rung spacing, the width and the number of rungs, and draws the rails with reference numbers down the side. Those numbers feed both the wire numbers and the tags, so the ladder comes before the components.
Then the mechanism beginners miss: a wire is a line on a wire layer. Wire types are defined per drawing, each with a layer, colour and size. Anything drawn on one of those layers with the wire command is a wire, it breaks at components, takes a number, joins a network and appears in the from/to report. A line drawn with LINE on layer 0 plots identically and is invisible to every report in the package.
Components carry catalogue data, or they carry nothing
Insert from the icon menu, then use Lookup or the Catalog Browser to attach a manufacturer and catalogue number from the catalogue database. That attachment is what turns a set of symbols into a bill of materials. A symbol with no catalogue data appears in the Missing Bill of Material report and nowhere in the BOM.
Signals that cross sheets
A signal leaving sheet 3 and arriving on sheet 7 needs a source arrow at one end and a destination arrow at the other, tied by a signal code. AutoCAD Electrical then treats it as one network across the boundary, keeps a single wire number on both ends, and prints the cross-sheet reference beside each arrow. Skip the arrows and you have two unrelated wires with two numbers, and the from/to report will say exactly that.
Parent and child contacts
A coil is a parent: it holds the tag, the catalogue number and the contact allocation that comes with that part. Its auxiliary contacts, drawn wherever the logic needs them, are children, no catalogue data, just a pointer at the parent tag.
The cross-reference keeps them in step. The coil displays a table showing where each NO and NC contact is used; each contact displays the coil's location. Move a contact to another sheet and both ends update. Draw four auxiliary contacts against a part that has two and the software tells you, instead of the panel shop discovering it.
Panel layout from the schematic
Panel drawings are generated, not redrawn. Insert Footprint reads the schematic component list, looks up a footprint for each catalogue number and places a scaled outline for you to arrange on the plate. The footprint stays linked to its schematic component, so the panel BOM and the schematic BOM cannot drift apart. What it will not do is think about heat, segregation or door swing, see the control panel GA drawing for that.
The three reports
| Report | What it gives you | What it needs |
|---|---|---|
| Bill of materials | Components rolled up by part number, with quantities | Catalogue data on every symbol |
| Wire from/to | Each wire number with both ends, component and terminal | Location codes on components |
| Terminal plan | Strips with jumpers, wire numbers and cable references | Real terminal symbols, not generic blocks |
All three export to Excel, CSV or a table in the drawing. That is the answer to "why not plain AutoCAD": the drawing is a database, so a schedule is a query rather than a typing exercise.
A worked example
A 5.5 kW motor at 415 V, 50 Hz draws about 10.6 A at full load, from I = 5500 / (1.732 x 415 x 0.84 x 0.86) with 0.84 power factor and 0.86 efficiency. That sizes an 18 A AC-3 contactor and a 9-13 A thermal overload set to 10.6 A, class 10 to IEC 60947-4-1.
Put the control ladder on sheet 2, first reference 100, 20 rungs. Stop and start pushbuttons on line 101, starter coil on 103, seal-in contact beside the start button, run lamp on 105. With sheet-plus-reference numbering the seal-in wire is 2101 and the coil feed 2103. With catalogue numbers on the contactor, overload and pushbuttons, the BOM comes out with correct quantities and the from/to report lists wire 2103 running from the overload auxiliary terminal to the coil terminal. Nothing there was typed into a schedule.
What goes wrong
Drawing wires with the LINE command. The drawing looks finished and the reports come out empty, because a line on a non-wire layer is not a wire. Symptoms: no wire number appears, the line does not break at a component, the from/to report is short. Convert lines to wires, or redraw with the wire command.
Renaming or moving files outside the Project Manager. The project file stores paths. Rename a DWG in Windows Explorer and the project points at a file that is gone, while the renamed drawing belongs to nothing. Use the Project Manager's own rename, remove and replace.
Ignoring the catalogue. People who came from plain AutoCAD place symbols, never open the Lookup dialog, and conclude the BOM feature is broken. It is not; it has nothing to report. Run the Missing Bill of Material report before issuing anything, it is the fastest check of whether the drawing is really a database yet.
What to learn next
Terminals and PLC I/O, because that is where a schematic stops being a circuit and becomes a wiring instruction: terminal strip editing, jumpers, multi-level terminals, and PLC modules with addressed I/O generated from a spreadsheet. Then compare the packages in EPLAN vs AutoCAD Electrical vs SOLIDWORKS Electrical, and read control panel wiring standards in India so the drawing matches what the shop will build.
Learn this, free
The courses that teach this
Every lesson, the written notes and the practice are free with an account. Only the certificate is optional and paid.
