- First pass at writing this*
Notes from the cammakespace user group.
It's quite involved. Yes you can self certify, but you can't just tick it off and say "done" - it needs to be well documented and in many cases externally tested.
There are very few things that are not CE covered. Simple items (that are not toys or safety critical) can be exempt - eg a comb. Kits are exempt (eg requires soldering iron to assemble).
> What are the potential repercussions of getting it wrong? etc
Potential prosecution by the trading standards authority, increased liability if anything goes wrong with sales of your item, invalidation of insurance.
http://www.emcfastpass.com/cert-ebook/ Is a decent start point. Lots covered, and you'll have a decent idea of what you do and don't need to do. Well worth the $32 imho. (I do have EMC chambers and test gear - but get my stuff tested and certified externally, although I'm starting to ponder self-certifying for the easy stuff)
My experience of CE marking (based on a couple of industrial products) is that you need to show the product is safe. That's all.
Like many legal requirements though, there are standard, accepted/assumed ways of proving it's safe that aren't necessarily intuitive to an outsider. I think its generally accepted that your product is safe if you have a documented, reasonably robust risk assessment for the use case, an FMEA to show that the product doesn't become lethal if one component fails (there are various levels of acceptable risk/redundancy that probably don't apply to your product) and that you have documents to show you meet all the relevant safety standards for the technology/implementation/application. Typically that means the 'Product Directives' but there are many that could be applicable, have a look at: http://www.ce-marking.org/how-many-directives.html Some of the directives can be met by showing compliance was 'designed in', such as meeting the necessary level of insulation or isolation. Others need to be demonstrated by testing, such as EMC or can be very involved. For one of the products I'm working on at the moment, the standards require you to life test or abuse/overload test about 30 complete products and some of the tests take weeks to complete.
You can self certify but if its your first product its probably best to get an external expert to review your technical file. I can recommend someone I've used before.
By way of an example, have a look at the Micro:bit Declaration of Conformity: https://microbit0.blob.core.windows.net/pub/hkeghjes/declaration-of-conformity.pdf
The micro:bit didn't need to be classified as a toy, so for some info regarding what is a toy and toy safety please have a look at this: http://www.hobbycraft.co.uk/toy-safety
The 'Technical File' mentioned in the micro:bit DoC would include, amongst other things, the documentation showing the safety check results, the hobbycraft link has some info on what else would be in that Technical File.
This is me being captain obvious, but... The point in time at which you obtain a CE mark needs to be factored into your product budget. If you've already have gone thru certification then a change in the product design may, or may not, require 1 (or more) tests to be executed again, which is extra cost and introduces time delays.
With no mains connection you would still have to comply with radiated emissions, immunity to radiation and immunity to ESD. EMC is self certified and complaint driven so if you're 100% certain that either you're fully compliant or nobody will ever complain about it, then you might choose to take no action (but I would never suggest that in a professional capacity!). For something a little more complex the only sensible approach is to test it at an EMC house, which will cost you around £500 for a half day pre-scan with a technican, and maybe two to three times that for a full test with report. This doesn't include electrical or mechanical safety, just EMC. The amount of safety testing depends entirely on the nature of the product. A kid's toy with a kitemark is a whole different ballgame to a musical greeting card.
Oh, also keep in mind that for emissions, if the product is normally used with something else, that something else needs to be in the test chamber as well. So if you make a USB keyboard, you need a PC in the chamber too. This only applies if the thing is physically connected - radio is OK. Of course, if you DO have a radio you also have to be compliant with the relevant band requirements for each licensing authority in which you'll ship. If you have only one radio and you use a pre-certified module you can avoid this.
If you do have a mains connection, whether direct or via a power adaptor, you also need to comply with conducted emissions and immunity as well as the appropriate safety standard which depends on the electrical class. This is when you'll discover that your Chinese imported "CE Marked" power supplies really aren't (compliant) and why so many products ship with massive after-thought ferrites on their power cable.
You'll need to meet different standards for different territories. You're unlikely to get a container past customs in the US without an FCC conformity declaration - even if you think your product is exempt. In most cases CE meets or exceeds other standards, and often you can get multiple reports from a test house for a little extra. A CE mark alone isn't good enough to ship into the US (FCC) or other non EC territories - you need their mark too.
Failure to comply is a non event if nobody (including customs) complains about your product. However if they do, first your stock gets impounded regardless of whether it's compliant. Then your product gets tested and if it's found to be non compliant you're in trouble. If it's then discovered that you haven't made reasonable efforts to establish compliance before shipping with a mark you're in quite serious trouble. Stock does get destroyed and very occasionally company directors go to prison (I'm sure it's the nice kind though).
I'd recommend DB Technology who are just north of Cottenham, aren't too expensive, know their stuff, but tend to be busy. http://www.dbtechnology.co.uk/
For larger or more obscure jobs, or when DB are booked up for months, I'd recommend York EMC, although they're not local (Bristol or Leeds).
There's an EMC exemption for exactly this sort of thing (DC-only, no chance of radiating, no relevant susceptibility). I think that a battery torch was the example given. You'll need to document that that's the route you've taken. Links in that ebook I pointed at earlier. (But you were asking for more generic advice...)
If you're trying to get a product certified might be worth contacting UL ( http://uk.ul.com/). Think they are one of main companies for certification. Their reps and are always at hardware startups events and they give a free a consultation which might give you the specific regulation details you need to conform to. (I can dig out their details if interested). I believe they are expensive but it might of use.
Full agreemenrt with Rob on DB-Tech for a local EMC/ESD (and soon RED) test house - I use them for all the stuff I manage, they are really helpful and their prices are better than many other labs.