What is equally interesting is how many hard-core AutoCAD users don’t know that Autodesk actually produces about 140 products that cover the full gamut from high-end graphics animation software such as that used to produce Avatar, through to vertical-application products for mechanical, architectural, civil, GIS and electrical control design.

Electrical control design? Yes, a special flavour of AutoCAD for electrical control designers has been around for several years. If you are already using AutoCAD Electrical (www.autodesk.com/autocadelectrical) you may want to jump ahead to the “new stuff” section below to see the new features, but if you haven’t experienced AutoCAD Electrical before then stick around to see some of the magic that it can do.

You may have customized your copy of standard AutoCAD to include a small library of standard symbols, but AutoCAD Electrical comes with a library of “thousands” of symbols and graphical representations for things like switches, relays, motor starters, pilot lights, pressure switches, PLCs, as well as hydraulic, pneumatic, P&ID devices and so on.

Better yet, you can simply select them from a catalog of standard items representing as many as 45 different manufacturers, depending on how much of the master catalog you choose to install.

There is also a library of standard “circuit builder” modules for common schematic modules. For example, it took just two mouse clicks and a couple of seconds to create and insert a 3-phase reversing motor control circuit.

But wait! There’s more!



Each item contains pertinent data about itself so that AutoCAD Electrical is able to analyze your circuit. For example, it knows how many poles a selected relay has and what load they will carry and it will object if you try to connect too many circuits or too heavy a load to it. Error-checking is done in real time as you work.

The application also automatically calculates wire sizes and fuse or circuit breaker capacities based on the electrical load and on electrical code requirements.

AutoCAD Electrical is fully parametric, so that things like wire and connection numbers and component tags can be automatically assigned. If you later change anything then everything updates. Note that “everything” includes both the schematic diagram and the related control panel layout drawing.

Circuits can be designed in point-to-point or ladder formats. If you insert a new rung in a ladder then everything automatically pushes down and spaces itself properly.

An important point to note here is that AutoCAD Electrical is based on AutoCAD, so it still uses the standard .dwg file format. In fact, a couple of mouse clicks switches you back and forth between Electrical and standard AutoCAD 2D or 3D on the fly. A circuit design file does not require any extra support files. It can be opened by a copy of standard AutoCAD, and will survive a round trip through it and back into AutoCAD Electrical.

AutoCAD Electrical can generate several output reports, and can also read certain types of data file back in. For example, schematic data can be exported to Autodesk Inventor Professional (3D solid modeling software) or Inventor Routed Systems where it can be used to derive the actual 3D layout of components and hence the 3D wiring looms, along with the nailboard layouts required to build the looms.

Inventor data can also be fed back to AutoCAD Electrical. For example, you may find that it makes more physical sense for a particular set of wires to be connected to a specific contact set in a relay without changing the logical operation. The Inventor revisions can be fed back to AutoCAD Electrical to update the schematics.

AutoCAD Electrical can also import a PLC I/O assignment file that was created in Microsoft Excel and then automatically generate the corresponding ladder diagram.

Because AutoCAD Electrical is based on standard AutoCAD, the 2011 release includes all of the new 2D and 3D enhancements and additions from regular AutoCAD 2011.

Now for the new stuff specific to 2011 Electrical.

Catalog lookup has been improved. For example, it is now possible to sort and filter catalog entries, including the use of wild cards. In addition, the specific components used in a project can be extracted to a project-specific database. This can be used to permit only certain catalog items to be used for future selections.

Wire types are defined within each drawing, but it is now possible to import wire types from an existing drawing or template. This can be done for specific drawings or for all the drawings in a complete project set.

Specific panel components can now have fixed item numbers assigned to them. They will not change if Resequence Item Numbers is run later. This could be very useful when making additions or changes to an existing panel. In addition, panel component resequencing can now be limited to the items from a particular manufacturer or manufacturers.

Electrical commands are now aware of location boxes. Installation and location values update automatically if you insert or move parent components into or out of location boxes.

AutoCAD Electrical 2011 now allows collision detection to be turned on and off. Unfortunately the documentation is very sparse and a little vague. I eventually “sort of” figured it out.

It seems that if collision detection is on (the default) and you are placing a wire between two points in a schematic, and the wire will collide with a component located between the two points, then normally the wire automatically routes itself around the component – but if collision detection is turned off then the wire automatically connects itself into and out of that component on its way to the ending point.

At least, that’s the theory. In practice I found the operation to be a little vague. There is an on/off example that it took me a while to duplicate, but I can’t say that I fully understand how or when it works. Another example of the vague documentation is the fact that it took me a few minutes to figure out that the “global variable GBL_wd_skip_collision_check” is not a normal AutoCAD system variable but is an AutoLISP variable.

All in all, AutoCAD Electrical 2011 is a powerful, versatile tool that should be just about mandatory for any electrical control designer.

Bill Fane ( This e-mail address is being protected from spambots. You need JavaScript enabled to view it ) is a independent software reviewer for Design Product News and Cadalyst magazines, and retired mechanical engineering instructor at BCIT.