I realize that this may be "opinion based" but I would like some general advice and feedback anyway and it is a engineering question after all.

I often feel overwhelmed by the sheer amount of information available with respect to European technical standards (EN standards) alone. There are just so many things to consider and most papers are for purchase only. So figuring out what documents to acquire is a first hurdle.

Working with only one or two engineers per project, I have a hard time feeling confident that we took everything important into consideration.

So far, we (small company) were mostly concerned to meet the basic safety aspects and to design with EMC in mind. Then we went to a EMC testing facility and checked that we don't exceed the emission limits, performed susceptibility testing and verified that our product is not sensible to ESD. But so far, it was more common sense engineering, than aiming to fulfill specific requirements with respect to application scope and type of device.

Is it maybe common to consult someone specialized on this topic?
Is there a good reference/book/on-line resource I should be aware of?
What is a good approach to evaluate normative requirements for a new device/design, maybe someone can share some experiences from a real world project?

  • \$\begingroup\$ Worth stating your intent, at least in outline : something for your own use, sale to public, sale as components to other professionals, 1 off or making a million? \$\endgroup\$ – Brian Drummond May 28 '15 at 12:05
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    \$\begingroup\$ @BrianDrummond: Well for my current employment its mostly electronic devices for the industry that some electrician would handle/install but a common person would interface with. Like electronics for a park ticket machine with maybe several hundred units. But I am fine with answers/suggestions staying general. \$\endgroup\$ – Rev1.0 May 28 '15 at 12:35

If you are designing for a European market start with the directives that are needed to CE mark your product. These are all freely available on several websites. Work down these to decide what directives are applicable then it should become clearer what EN documents are required to be adhered to for your product.

Here is a good starting point. It's the UK government's CE marking guide and contains a list of all the directives that may apply.

Here is also another useful website where you can download pdf copies of all the directives. This one is the low voltage directive - wade through until you get to section 1 (general conditions) and you can seek further guidance from this site. If you download the pdf of the guidance and go to "scope" it begins to list the requirements and specifications that may be involved.

There is guidance available for all directives. You should also download the "Blue Guide" - it has a lot of good information and links but is more than a ten minute read.

And finally this document entitled "the new approach guide" contains flow diagrams of how you should approach testing your product.


It can seem pretty horrible, but the reality isn't as bad as it might first appear once you get past the number codes and terminology for everything. The main thing to remember is that almost all the standards are, in the end, quite sensible, and if you follow good design practices you will likely end up with a product that is not too far from where it needs to be. So don't get too fixated on the standards at the start - think more about designing a high quality product.

Another useful thing to do when you are starting out is simply find an existing product that is similar to what you are trying to do (from a reputable manufacturer). The manufacturer for this will have something called a 'declaration of conformity' for each product (normally found on their website) and if you have a look at this it will list out all the EN standards they are compliant with. This will give you a good idea of what you need to be looking at.

In the end if it is a commercial project you will very likely get a third party test house to review everything for you and confirm which standards you need to meet. However for many simple low energy products it is quite reasonable to just do this yourself as many products only require EMC, WEEE and RoHS and meeting these standards is not that difficult these days.

  • \$\begingroup\$ Looking at the "declaration of conformity" from a similar product is a good idea. So far, we were mostly concerned to meet the basic safety aspects and to design with EMC in mind. Then we went to a EMC testing facility and checked that we don't exceed the emission limits and that our product is not sensible to ESD and we performed susceptibility testing. But I have the urge to get a better overall understanding of the what/why/when, and not just follow "Do this and that and be done". \$\endgroup\$ – Rev1.0 May 29 '15 at 6:54

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