Raymond,
You’re in the gray area. You’ll get answers ranging from: “Yes, you must test”---- usually from test labs “I would test this if I were you” -------------usually from manufacturers with their own in-house test facilities or well established compliance departments. (for instance, you would see a job title such as “Sr Homologation Engineer” “No, I wouldn’t test” ------------- usually from manufacturers and distributors who don’t have in-house test facilities…However, you won’t see this answer much in black and white on the forum because it is a forum of people who are obviously very interested in EMC and usually err on the side of caution. “Pay me $$$$ and I’ll provide you Technical file to use for your whole family of devices”-------------------usually from a consultant. I did see one reply to your question that was unique “Get some cheap testing without a report and file away the data”. That was interesting. I don’t know if I like it. If you pass, you might just as well pay the extra couple hundred bucks and get a full blown report. An accredited report from a calibrated lab is the only thing that will hold water if your device is found in excess of the emission limits at some customer’s site. However, if you fail by a mile…at least you found out without spending a lot of money…so maybe there is some merit to the idea. For most of the CE directives, there is no requirement to actually test. There is only a requirement to serve due diligence. Usually, due diligence includes some form of testing, or at least an engineering evaluation. You have to balance risk vs cost. This is a question where you earn your money as an EMC engineer. You’re correct when you say that many (if not most) configurations of equipment on the market have never been tested as a system. However, when you put a system together, you assume some responsibility for ensuring that you aren’t violating the connection and interface requirements of the components. You also need to figure out whether you are a manufacturer or a distributor. The current state of the art for declaring conformity is much like building a case for trial. You build the best case of evidence (data, declarations…) that you can. We all make this decision on a weekly, if not daily basis. All I’ll say is…I’ve used all of the first three answers at different times. I’ve never used the fourth or fifth. No matter which choice you make, you should have access to a copy of the relevant standards so that you can make an informed decision. I hope this helps. Chris Maxwell Design Engineer Nettest _____ From: [email protected] mailto:[email protected]] On Behalf Of [email protected] Sent: Wednesday, October 20, 2004 12:16 PM To: [email protected] Cc: [email protected]; [email protected]; [email protected] Subject: RE: EMC testing Dear Michael, I have learnt it, CE + CE does not equal CE, since the official EMC Directive introduced. However, I did not see any solution or I overlooked the solution, if any. The above was brought from a case related to computer equipment. I do not know how it has been totally resolved. How is a monitor tested with possible computers connected? Probably no body knows in the world? Even though I bought a branded full set of computer consisting CPU unit, keyboard, mice and monitor and they all have their own declaration in their instruction booklets separately and I have not seen one declaration for all devices. Did you see any? Thanks and regards, Raymond Li OSA Ltd. <[email protected]> 20/10/04 02:18 AM To <[email protected]>, <[email protected]>, <[email protected]> cc <[email protected]> Subject RE: EMC testing CE + CE does not equal CE Michael Sundstrom NOKIA TCC Dallas / EMC ofc: (972) 374-1462 cell: (817) 917-5021 amateur call: KB5UKT From: [email protected] mailto:[email protected]]On Behalf Of ext Richards, Carl Sent: 19 October, 2004 10:57 To: [email protected]; [email protected] Cc: [email protected] Subject: RE: EMC testing Raymond, I think you need to decide how important it is and have this discussion with your management rather than asking us how important your business is. To me it's it's clear cut, you *intend* to sell them to connect together, you have no combined official EMC data for the pair, although you have official data for each item. If it were me I'd pop along to a lab for some private and cheaper EMC testing for both units connected together, a quick and dirty check to make sure that singularly the units EMC performance aligns with previous results and then ask for testing without a report but with results if cost is the gating factor; all being well pop the results in the folder and sign the product release docs and DoC, and go home for a well deserved cold beer. Next product change, budget the Regulatory costs for both units. Carl Richards, Regulatory Compliance Manager, Aspect Communications E-mail [email protected] Tel +44 (0)208 589 1461 Fax +44 (0)870 460 1950 From: [email protected] mailto:[email protected]]On Behalf Of [email protected] Sent: 19 October 2004 16:40 To: [email protected] Cc: [email protected] Subject: Re: EMC testing Dear Josh, I believe my case exists many years but probably I do not know the solution. For example, when you buy a AV centre amplifier, you will never use it on its own but connect it with lots of peripherals: DVD player, receiver, VCR, TV, etc., I hardly believe the amplifier is tested with all peripherals during EMC testing. Similar example is computer. Can someone shed some light on the existing solution to similar type of products in reality. Regards, Raymond Li OSA Ltd. Josh Wiseman <[email protected]> 19/10/04 11:13 PM Please respond to [email protected] To [email protected] cc [email protected] Subject Re: EMC testing Raymond, You are rolling the dice in this case. If the two units are not tested together you can not be sure that the 2 units do not interact with each other, especially with the cable between them. Josh [email protected] wrote: > > Dear All, > > We have a product (portable DVD video player with 8" LCD display + 8" > LCD display) and they have got EMC compliant report separately and sold > separately before. If we sell them together as one unit, do we need to > test them all together again. The connection between two sets is via a > cable from output port of DVD player to input port of the display. They > are powered by batteries, AC-DC adapter or car adapter. Your advice is > appreciated. > > Thanks and regards, > * > *Raymond Li > > OSA Ltd. > ---------------------------------------------------------------- This > message is from the IEEE Product Safety Engineering Society emc-pstc > discussion list. Website: http://www.ieee-pses.org/ > > To post a message to the list, send your e-mail to [email protected] > > Instructions: http://listserv.ieee.org/listserv/request/user-guide.html > > List rules: http://www.ieee-pses.org/listrules.html > > For help, send mail to the list administrators: > > Ron Pickard: [email protected] Scott Douglas [email protected] > > For policy questions, send mail to: > > Richard Nute: [email protected] Jim Bacher: [email protected] > > All emc-pstc postings are archived and searchable on the web at: > > http://www.ieeecommunities.org/emc-pstc > ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to [email protected] Instructions: http://listserv.ieee.org/listserv/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Ron Pickard: [email protected] Scott Douglas [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to [email protected] Instructions: http://listserv.ieee.org/listserv/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Ron Pickard: [email protected] Scott Douglas [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to [email protected] Instructions: http://listserv.ieee.org/listserv/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Ron Pickard: [email protected] Scott Douglas [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to [email protected] Instructions: http://listserv.ieee.org/listserv/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Ron Pickard: [email protected] Scott Douglas [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to [email protected] Instructions: http://listserv.ieee.org/listserv/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Ron Pickard: [email protected] Scott Douglas [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
