If I purchase a kit from a website like overclockers.co.uk which includes a quality power supply, motherboard, CPU, etc. Everything is CE certified and all components are the highest grade. All I am doing is placing the components in an enclosure, so I cannot imagine a circumstance where they will violate CE.

What would be the most cost-effective (and legal!) way to add the CE markings to the finished product?

EDIT: This is to sell an assembled PC

  • \$\begingroup\$ Are you selling it, or is it merely for your own use? \$\endgroup\$ – Brian Drummond Apr 21 '20 at 21:59
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    \$\begingroup\$ CE is largely on the honor system but you need to keep a paper trail. \$\endgroup\$ – pjc50 Apr 21 '20 at 23:04
  • \$\begingroup\$ This is to sell it \$\endgroup\$ – Hackeron Apr 21 '20 at 23:12
  • \$\begingroup\$ RL anecdote: I remember a PC where the graphics card sometimes activated some special function in graphic-intense programs. Likely some high frequency clock signal. When that happened, an annoying, audible coil noise started ringing elsewhere in the PC, from inside the PSU. -> \$\endgroup\$ – Lundin Apr 22 '20 at 11:51
  • \$\begingroup\$ This would be a typical case of failing CE, because one intended function of the product "PC" is to produce audio. So if some coil starts screaming because of EMI, it's not compliant to the EMC directive. This was a Corsair PSU and a Nvidia card, both supposedly high quality brands, CE marked and tested against numerous standards. But no, either one or both products failed conducted and/or radiated susceptibility/emissions. The PC manufacturer put the PC on the market, so they are the responsible party. \$\endgroup\$ – Lundin Apr 22 '20 at 11:51

You need to CE mark the PC but this doesn't necessarily mean you have to pay for third party EMC and environmental tests, because the individual components are already tested (or so they say).

You might be able to reason in your technical documentation that placing the components next to each other will not create any EMI scenario that the component manufacturers did not expect. This would include things like wires or metal casing not causing unintended EMI phenomenon by acting as antennas or generating fields etc. Similarly, the PSU needs to be encapsulated so that the customer can't touch the mains voltage even if they open up the computer. If that's not the case, I would imagine that you will have to do a new IP test of the outer PC casing.

The EU directives that you need to address in your EC declaration of conformity should be RED, LVD, EMC and RoHS. Each such directive has a lot of rules and normative standards, but they also have a way to demonstrate compliance without enlisting a test house. Example from the RED directive 2014/53/EU (article 17 §3) where you have 3 different options of demonstating compliance:

(a) internal production control set out in Annex II;
(b) EU-type examination that is followed by the conformity to type based on internal production control set out in Annex III;
(c) conformity based on full quality assurance set out in Annex IV.

If you go with option a) you then need to do the following:




  1. Internal production control is the conformity assessment procedure whereby the manufacturer fulfils the obligations laid down in points 2, 3 and 4 of this Annex, and ensures and declares on his sole responsibility that the radio equipment concerned satisfies the essential requirements set out in Article 3.

  2. Technical documentation
    The manufacturer shall establish the technical documentation in accordance with Article 21.

  3. Manufacturing
    The manufacturer shall take all measures necessary so that the manufacturing process and its monitoring ensure compliance of the manufactured radio equipment with the technical documentation referred to in point 2 of this Annex and with the relevant essential requirements set out in Article 3.

  4. CE marking and EU declaration of conformity
    4.1.The manufacturer shall affix the CE marking in accordance with Articles 19 and 20 to each item of radio equipment that satisfies the applicable requirements of this Directive.
    4.2. The manufacturer shall draw up a written EU declaration of conformity for each radio equipment type and keep it together with the technical documentation at the disposal of the national authorities for 10 years after the radio equipment has been placed on the market. The EU declaration of conformity shall identify the radio equipment for which it has been drawn up. A copy of the EU declaration of conformity shall be made available to the relevant authorities upon request.

  5. Authorised representative
    The manufacturer's obligations set out in point 4 may be fulfilled by his authorised representative, on his behalf and under his responsibility, provided that they are specified in the mandate.

That being said, in addition to performing tests, test houses are also very good at helping out with all this EU bureaucracy. You can usually hire them as consultants to tell you what needs to be done, documentation-wise.

  • \$\begingroup\$ Useful search term : "technical construction file" basically covering the above. \$\endgroup\$ – Brian Drummond Apr 22 '20 at 15:02
  • \$\begingroup\$ @BrianDrummond Indeed, that's the big and burdensome one. Particularly in regards to RoHS documentation where you need to show that every component used is RoHS compliant by pointing to its documentation. These directives pretty much all assume that every company can afford to employ a full-time bureaucrat working only with regulations and documentation. \$\endgroup\$ – Lundin Apr 23 '20 at 6:36

You, as a system integrator, cannot say that your system passes CE unless you test it and certify it yourself. You can't claim compliance of the whole box just because the components pass individually. It could very easily fail due to some other unforseen use case that causes an interaction between the parts that leads to an EMI failure.

Interference enforcement is kind of an honor-system. If someone buys an assembled box from you, regardless of whether it uses CE certified components or not, and it causes an EMI problem in the field that is traced to the box you sold them, they will be obliged to fix it. Which means the box might come back to you.

Even if you don't resell your box, if EMI is traced to you, you're still obliged to fix it. It doesn't happen often, but it does happen.

  • \$\begingroup\$ I know, I wasn't asking that, I was asking where can I go to get the build CE certified in a cost-effective way. \$\endgroup\$ – Hackeron Apr 21 '20 at 23:13
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    \$\begingroup\$ A system integrator can do that for you. Companies like Supermicro, AIC and others can do that at competitive pricing for server and workstation platforms. \$\endgroup\$ – hacktastical Apr 21 '20 at 23:21
  • \$\begingroup\$ Or you could write CE and call it China Export or what ever you want. \$\endgroup\$ – CFCBazar com Apr 22 '20 at 4:12
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    \$\begingroup\$ You can claim CE compliance just fine without 3rd party tests. But you need a declaration of conformity and you will be the responsible party if EMI hits the fan. \$\endgroup\$ – Lundin Apr 22 '20 at 11:53

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