CE self certification - Page 1
Forum section: electronics / general

author: zoodle
author_rank: Newbie
timestamp: November 21, 2019, 02:36:11 pm
content: I have prototyped an environmental sensor which I would like to turn into a product with a small production run. I would like to get a CE marking by self certification but am unsure which directives apply and how to go about the process.Has anyone been through this trial and have a good understanding of what is required?The product consists of two units joined by a cable. The sensor head contains the environmental sensor, a small microprocessor and an RS485 transceiver chip for sending data over the cable. The other unit is a USB to RS485 converter based on an FTDI chip and a small 5V to 9V power supply module for supplying power to the sensor head over the cable.Is it sufficient to show that by good layout design and appropriate component choice that EMC requirements are met?Any help is appreciated!

author: Mangozac
author_rank: Frequent Contributor
timestamp: November 21, 2019, 09:48:03 pm
content: Quote from: zoodle on November 21, 2019, 02:36:11 pmUnfortunately, while an indication of good design work, those things aren'tproofthat your product meets EMC requirements. You need to either do the tests yourself (which isn't possible without some very expensive equipment and testing knowledge) or employ a test lab (they don't have to be accredited but if the results are ever called into question it will be your liability). It sucks, I know, but this is just the way it is.I'm all for self certification and companies being under complete control of their products so I believe it's worthwhile developing an understanding of the CE process rather than just handing over to an agent. Unfortunately there are no simple guidelines that I've seen.It sounds like your device is powered by a plug pack? If so then as long as the power supply already has CE approval you won't have to worry about the Low Voltage directive. EMC (emissions definitely but I'm not sure if immunity is always applicable for CE) is needed. RoHS is another obvious one. Depending on the size of your production run there will likely be some form of WEEE to comply with too. Have a look around to see if there are any standards relating specifically to your type of device - if so there's a good chance that there may be a related directive.I hope that helps!

author: wilhe_jo
author_rank: Regular Contributor
timestamp: November 21, 2019, 11:19:54 pm
content: Well emc could be easy.<108Mhz at the PCB means measurements just to 1GHz.485 could mean measurements on the communication lines are not needed. Etc.You can definitely help yourself...However, if you have an intended use which includes outdoor use. You'll need immunity requirements for the ac/dc brick (or a connected pc) which no (affordable and) available unit will comply with. Just USB Power might cause serious troubles with pretty real disturbance sources...And pls do not underestimate the LVD. You might not fulfill the voltage boundary, however USB-C may supply enough energy to cause a fire hazard.... so I would do a formal risk analysis...All in all, it could be easy or unfeasible.73

author: Mangozac
author_rank: Frequent Contributor
timestamp: November 21, 2019, 11:39:20 pm
content: Quote from: wilhe_jo on November 21, 2019, 11:19:54 pmThe LVD still wouldn't be applicable. The scope is literally:Quotehttps://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:32014L0035That said, certainly if using high power levels at an extra-low voltage one would want to ensure that material flammability is considered as part of good design practice and as suggested should be part of the product risk analysis.Exactly which EMC tests are required depends on a lot of things, so can't accurately be advised based on the information supplied thus far. The first step is to identify the relevant EMC standard based on the type of device.

author: Larry80
author_rank: Contributor
timestamp: November 25, 2019, 04:49:51 pm
content: I think you could self certify a product. The laws are very strict, but there might not be a single case that has questioned EMC test based on the accreditation (or lack of) for the sake of it. Usually some agency will ask for the tests, when something bad happens. They have no reason to question your tests otherwise (it would require to bring it to court perhaps, costly endeavour). You must cough atleast 5k€ for any reasonable pre-compliancy equipment though, so self certification is not free either.And when something bad has happened, no amount of testing will save you, because the product has demonstrably failed. On corner cases perhaps you could lawyer up and pay millions in court to battle against your liabilities. All chinese small "brand" products are pretty much uncertified, the small importer bears (often unknowingly) the responsibility.This is why you should always protect your personal assets with a company shell, which is the manufacturer and retailer. Design your products well, so you won't get into serious trouble. Your main concern should be fire hazards as everybody is pointing out. Buy only parts from good sources and do a single-component fault analysis on any components which are supplied by power over 5W (i dont remember exactly the wording of standard, but its somewhere around that ballpark).EMC failure will force you to recall the products, but nobody will be physically injured. There are practices how that is done and it might or might not be costly (again, protect your personal assets).What standards apply? Best option is to take similar certified product and study their directives (they must be listed). That will allow you to learn and they are interesting read i find. There are extremely cheap legal options for standards online, but i do not give you links or hints, as i want to keep the source as my own (it might disappear from the traffic). Typically standards cost 150-500€ and you need several of them, but from correct sources they are couple of euros only (talk about markups!).

author: SiliconWizard
author_rank: Super Contributor
timestamp: November 25, 2019, 07:28:35 pm
content: Quote from: zoodle on November 21, 2019, 02:36:11 pmOf course, this is not a CE marking consultancy here.But what I think has reasonable chance of applying, given your short description, are the Low Voltage (2014/35/EU) and Electromagnetic Compatibility (2014/30/EU) directives.One that should be checked as well would be the Measuring Instruments directive (2014/32/EU), not sure it applies here, but to be checked for sure.Quote from: zoodle on November 21, 2019, 02:36:11 pmNot really: EMC is a tricky thing anyway. There's absolutely no way you can prove compliance without actually testing it. That said, for a self-certification, nobody is going to ask you anything, so the amount of technical documentation and test reports you have is up to you. Until something goes wrong in the field and your company gets sued. What this means here is that, if you're confident enough in your product reasonably meeting the requirements from the relevant directives, and you assessed the risks as low, you could postpone expensive tests until the product has sold and you have more cash. Not that I'm actively promoting this, but sometimes you don't really have a choice. What you could do, though, is have a preliminary EMC test (much less expensive), which you won't be able to use as proof of compliance, but will give you more confidence in putting it on the market this way.

author: zoodle
author_rank: Newbie
timestamp: November 26, 2019, 10:25:18 am
content: Alright guys, thanks for all the feedback! I think it's helped me focus on the way forward.It looks like I need EMC but not LVD. I have identified a testing house here in the UK which seems well priced so I will most likely go through the process with them.