Why use electrical CAD software for electrical documentation?

By Thor Vegge

Some electrical professionals consider whether to use constructional CAD software, such as AutoCAD, or to use electrical CAD software. This article focuses on the pros and cons of using the two types of CAD software for electrical purposes.

When you want to drill a hole in a wall, you use a wall drill. When you want to drill a hole in a board, you use a wood bit. If you use the wood bit for the wall, or the wall drill for the board, you can still do the job, but you will have to spend extra time doing it - and, well, the result might just not be as good as you expected.

When comparing electrical and constructional CAD softwares, you can pretty much use the same metaphor.

The powers of AutoCAD

AutoCAD is the most used construction CAD software worldwide - and for good reason. It is a brilliant tool for construction drawings, with loads of intelligent functions for shaping, changing diameters, viewing details from various perspectives, exploding drawings etc. When this is what you need, AutoCAD is the right software for you. This is what AutoCAD is designed for basically, this is the very core of the software.

Using AutoCAD for electrical documentation

But is it also possible to create electrical documentation in AutoCAD? Yes, you can do it, but it is not what it is designed for:

  • You can design electrical symbols - but you cannot add the necessary intelligence to them
  • You can draw ordering lists - but you cannot have them filled out automatically
  • You can write texts - but you cannot have them translated automatically
  • You can place relay coils and contactors - but you cannot have the references between them updated automatically
  • You can draw all the schematic diagrams you need - but you cannot have the diagrams gathered in the same file with automatic references between the pages etc.

Furthermore, the basic workflow in the software is designed for construction purposes. Adding extra electrical functions on top of the construction core, therefore gives a more timeconsuming workflow. - Just like adding constructional functions to an electrical CAD software would give a mediocre result.

Electrical professionals not trained in AutoCAD

Electrical professionals are seldom experienced AutoCAD users. Using AutoCAD for electrical documentation therefore requires an extra person to create the documentation based on sketches from the electrical professionals. This involves communication back and forth between the persons involved - including the misunderstandings this might bring.

Electrical professionals are seldom experienced AutoCAD users. Using AutoCAD for electrical documentation therefore requires an extra person to create the documentation based on sketches from the electrical professionals.

Investing in a software which enables the electrical department to create the documentation right away on their own terms, will therefore pay-off quite quickly.

The powers of Electrical CAD softwares

When you are producing the electrical documentation, you need distinctly other types of intelligent functions.

You need functions such as:

  • Automatic update of parts lists and connection lists
  • Automatic wire numbering
  • Support of electrical standards
  • Intelligent copying
  • Support of mounting correct drawing
  • Signal references between pages
  • Reference designations
  • Automatic drawing of connecting lines
  • Easy copying in and between projects
  • References between symbols
  • Automatically generated graphical cable and terminal plans
  • Communication with plc i/o tools
  • The ability to create and send ordering files automatically

... and many other electrical CAD features.

If you do business in other countries, you also need automatic translation of texts in drawings, and the ability to specify which types of texts to translate.

Component databases - one of the major time-savers

In an electrical CAD software the symbols in the diagrams can be intelligent. This means that they can contain an article number for the component they represent - and even more important: the electrical connection points of the components can be identified and handled intelligent by the software.

Being able to attach these types of information to a component, enables the software to update all kinds of lists automatically. This is for instance the case in our electrical CAD software, PCSCHEMATIC Automation, which also has all the facilities mentioned above.

For this software, you freely download component databases containing more than 26.000 article numbers from 47 component manufactureres. This opens up for a quite extraordinary workflow:

  • When you select a component from one of these databases, you get a pickmenu containing the electrical symbols for this component
  • When you place these symbols on the diagrams, article data are automatically transferred to the diagrams
  • Therefore the software can fill out all kinds of lists automatically, without you having to type in any component information at all.
  • When you copy these symbols in the diagrams, the copied symbols still carry the same article data as the originals.

This is really a time-saver in the daily work.

Combining the powers of electrical and mechanical CAD

But why not use the powers of both AutoCAD and an electrical CAD software at the same time? If you normally create e.g. ground plan drawings in AutoCAD, well, you can just continue doing so. Having completed the ground plan in AutoCAD, you just insert it in the electrical software as a so-called OLE object.

In the electrical CAD software PCSCHEMATIC Automation, you can then draw the electrical drawings on top of the AutoCAD file. The electrical information is then stored in PCSCHEMATIC Automation. When you need to make changes in the ground plan, you can then open it in AutoCAD directly from PCSCHEMATIC. You can then change the ground plan as you normally do in AutoCAD.

When you have completed the changes, you return the normal working mode of PCSCHEMATIC, and add more electrical information to your PCSCHEMATIC drawing - on top of the AutoCAD drawing. Working this way, it is even possible to create an AutoCAD ground plan directly from PCSCHEMATIC, and keep it as an AutoCAD document inside the PCSCHEMATIC document.

However, to have a workflow like this, requires the installation of both AutoCAD and PCSCHEMATIC.

Importing AutoCAD files

If you do not wish to purchase an AutoCAD license, you can make the two softwares communicate in another way. A typical workflow could here be that the architect constructs a ground plan drawing in AutoCAD, and export it as a DWG or a DXF file to electrical department, which uses PCSCHEMATIC. They load the file, and add the electrical documentation to the ground plan.

In this process they can use all the specially designed electrical functions in the electrical CAD software. Having added the electrical information, the electrical drawings are exported back to AutoCAD in DWG/DXF format, so that the architect gets the information that he needs. This is a quite typical workflow in PCSCHEMATIC. Apart from this, it is worth mentioning that creating ground plan drawings actually is quite simple in PCSCHEMATIC on a draft or tender material level - but you probably shouldn’t build a house from it.

When to use AutoCAD for Electrical documentation

However, before rushing off to purchase an electrical CAD-software, it is important to consider how often you create electrical documentation. If you only need to draw a circuit diagram once a month, including a parts list with only 38 components, you could still do with AutoCAD.

If these are your only needs, you should not invest money in an advanced electrical CAD software.

Free software for smaller documentation assignments

As an alternative, you can actually get the free PCSCHEMATIC Automation 40 software, which contains all of the advanced functions, but only allows you to save projects containing 40 electrical symbols. Along with this software you get the full manual for the software - ready to print.

A third option could be one of the Flex versions of PCSCHEMATIC, which are quite inexpensive, contains all of the advanced features in the software, and allows you to save projects containing up to 150 or 350 symbols.

Analyze your needs

Having said all this, the most important factor still remains: That you analyze what you really need, and how much time you spend creating electrical documentation in what just might be an unsuitable software for the assignment. It is always a good idea to check out the market, and compare the electrical features in the different electrical CAD softwares on the market.

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