Electrical design drawing standards

By Thor Vegge

Not everybody realizes how strict the EU electrical design drawing standards are - or that the requirements are being rigorously applied now in the European Union. It is hard to see a way out of getting an electrical design software, that makes it easy to meet the electrical design drawing standards.

“The latest European Union requirements within electrical documentation have been tightened so much, that you almost have to be a professor to document correctly. The ordinary electrician does not stand a chance to do so without being supported propperly,” says Ove Larsen, CEO in PCSCHEMATIC, the developers of Denmark’s best selling electrical design software, PCSCHEMATIC Automation.

The CAD software handles the electrical drawing standards

And it is not just for fun that you have to document correctly. The latest tightening up of the EU standards has implied that you can no longer have your machines CE-approved, when the documentation does not meet the EU electrical drawing standards. Therefore, Ove Larsen has automatic support of IEC/EN/ISO norms and standards as a top priority during the development of the electrical design software, PCSCHEMATIC Automation.

Intelligent support of Reference Designations

“To the horror of most electricians,” Ove Larsen continues, “it has now become mandatory to use reference designations for structuring the electrical documentation. The good news is, however, that it is not so hard to grasp the general concept behind reference designations, and that the program contains facilities, which makes following the international standards easy.”

You almost have to be a professor to create correct electrical documentation these days, without using a good electrical design software
- Ove Larsen, CEO

The scope of the reference designations can be for entire project pages, as well as for selected areas within the pages. The consequences this might have for symbol names in areas with reference designations, are handled automatically by the program.

Division in Chapters for better Survey

At the same time Ove Larsen has emphasized creating a set of frames, which makes it possible to better structure comprehensive documentation. It is possible to divide projects into chapters, and to create separate tables of contents for each individual chapter automatically. Furthermore, the built-in explorer window makes it possible to click your way to each individual component on the pages. This can be done easily due to the fact that all parts of the electrical documentation are gathered together in the same file.

Naming of Symbols due to current EN/IEC/ISO Standards

“During the installation of PCSCHEMATIC Automation, you will see that there are both created an EN60617 and an DB60617 symbol library,” Ove Larsen explains. “This is because we wish to be as clear as possible as regarding what is standard symbols. Therefore, the symbols in the EN60617 library, are symbols described in the standard. The symbols in the DB60617 library, are not directly described in the standard - such as compound symbols. However, these symbols are created according to the directions described in the standard. In other words, this is what the symbols would have looked like, if they had been described directly in the standard.

The reason why the library starts with DB, is because these symbols are used in connection with the many electrical component manufacturer databases for the electrical design software. The only thing changed in the new standard is the naming rules for some symbol types.”

Furthermore, it is possible to control the letter code directly from the component vendor databases for the program.

Following the standards when Copying Areas

With respect to the naming of terminals, detailed rules have now been specified for how to name/number the terminals. Therefore you have to name/number motor terminals and supply terminals as well as input and output terminals following different principles.

When copying an area the program first examines whether it has been drawn according to the new rules in EN60204-1,14.2.1 for naming of conductors and terminals. When this is the case, the program analyses which types of terminals it contains, and renames them according to their type. Because no gap in the numbering is allowed, the program simultaneously keeps track of which names/numbers have been applied for the various types of terminals.

When copying an area the program first examines whether it has been drawn according to the new rules in EN60204-1,14.2.1 for naming of conductors and terminals.
When this is the case, the program analyses which types of terminals it contains, and renames them according to their type.

When the copied area contains wire numbers, the copy is assigned the next available wire numbers - following the overall principle you have chosen for the wire numbering in the program. The applied reference designations and current path numbering are also taken into consideration.

Mounting correct drawing and Genuine wire numbering

According to the directions in EN61082-3, the documentation can be created as power control circuit diagrams or mounting correct drawing. “Unfortunately the fact is,” says Ove Larsen, “that you cannot make a program correct a project to become drawn mounting correct automatically. But PCSCHEMATIC can warn you when you draw something which is not mounting correct. Also, the program can detect the parts of existing projects which are not drawn mounting correct. You can then draw these parts mounting correct by yourself.”

“Furthermore, it is both allowed to use wire numbering and potential numbering. Because all wires must be uniquely identified, it is not sufficient only to apply potential wire numbering”, Ove Larsen emphasizes. It is therefore recommended to use real wire numbering, which is supported by the program automatically. Colour codes for cable wires and automatic potential numbering is also an option, so the program supports all approved types of wire identification.

Genuine Graphical Cable and Terminal Plans

Quite a few electrical design softwares advertise that they create graphical cable and terminal plans, but when you have a closer look, they turn out to be no more than cable and terminal lists. This is no longer sufficient according to the most recent EU standards.

PCSCHEMATIC Automation can therefore create genuine cable and terminal plans, which also can be updated automatically. The users of the program can set up for themselves the parameters for creating the plans, and then let the program do the remaining hard work.

However, you might have to make a few cosmetic changes after creating the plans. This is because it is not possible to create programming routines which foresees all possible situations. But Ove Larsen finds that 99 percent is perfectly possible. When you make subsequent changes in the documentation, the graphical cable and terminal plans can also be updated with these changes.

Follow the international electrical standards Easily

“From a general perspective it is not possible to create a program, which automatically follows all the norms and standards in the documentation. It requires that the user of the program also has some knowledge of the norms. For this user, I am confident we have created a program, which makes it as easy as possible to follow the European and international electrical design drawing standards.”

Book about electrical design drawing standards

To make it possible for interested users to get detailed knowledge about electrical norms and drawing standards, PCSCHEMATIC has created the book “Electrical documentation according to Standards” in cooperation with a board of professionals. The book is written by Jørgen Sommer from PCSCHEMATIC, and the English version has been available since 2004, and has been updated when necessary. The book is also available in Danish, Czech and Polish.

“So, as you can see, we do everything we can, to make it as easy as possible to follow the international and European electrical design drawing standards”, Ove Larsen finishes.

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