RE: Dwell time for Immunity under EN55024?
Dear Gert, Thanks for trying to answer my questions - I thought your comments are so misleading, at least I would have been fooled if I were not in the profession of regulatory compliance. I thought manufacturers have already taken too much trying to understand what are the routes to comply. Obviously - if the harmonized standards are available, simply following the standards would be sufficient to declare conformity, I believe that's why the standards are there in the first place. Why should we ask manufacturers to comply with essential requirements instead of following what standard says. TCF is only for certain conditions either when there is no harmonized standard available or the standard testing is not feasible to the EUT, etc. even though during TCF assessment, standard procedures should be followed as much as possible. If your comments were not misleading, I thought we should replace all test standards with test guidelines so that we could be exploring as much value-added essential requirements as possible and fully instilling our spirit of immunity testing. As test labs, we must be laughing as we are charging by time, and our manufacturers would never get out of debts. I would like to stop here, no more discussions on this, and you know time is money, once again we are charging you, dear manufacturers, by time Leslie I declare I am running a lab in California and partially own one lab in China. Gert Gremmen wrote:Hi Leslie, some answers: Is this called compliance testing or engineering verification?Anything that has to do with product quality (like EMI) needs to be addressed in termsof engineering. Can we do this and declare compliance? Sure you can declare compliance, as the European System is simply not targeted to complying with standards,but to complying with essential requirements. Of course you cannot declare compliance withthe standard (to the letter). Using standards is just a way to presumption of compliance. Art 10.1 EMCDIf you really DO deviate from the standard , you will needto follow the TCF route using a Competent Body to show compliance. Art 10.2 EMCD Any deviation of the standard is doomed to art 10.2 , but changing an undefined dwelltime to better meet the intention of the standard won't lead to a law suite. Several product type of standards do address the topic of dwell time btw. One never can get condamned by not following the prescriptions of the EMCD or standard, onlyby creating to much EMI or lacking susceptability (and other essential phenomenae). Gert Gremmence-test-Original Message- From: Leslie Bai [mailto:leslie_...@yahoo.com] Sent: donderdag 3 oktober 2002 21:37 To: Gert Gremmen; paul_sc...@mitel.com; emc-p...@majordomo.ieee.org Subject: RE: Dwell time for Immunity under EN55024? Gert Gremmen wrote: ... prescan with Increase frequency step size ! (watch out for resonances) Modify equipment to decrease fault response time (low pass filters ; software ) Build Specifc test features Write specific test software . I am wondering whoelse out there doing these - Is that not sufficient to demonstrate conformity by follwoing standard procedures? What specific test features, what specific test software, are they specifed in the standards? Is this called compliance testing or engineering verification? Of course you will be violating the standard; Can we do this and declare compliance? Leslie Bai NARTE Certified Engineer (EMC-002112-NE) www.siemic.com - Do you Yahoo!? New DSL Internet Access from SBC Yahoo! - Do you Yahoo!? New DSL Internet Access from SBC Yahoo!
Re: Dwell time for Immunity under EN55024?
I read in !emc-pstc that Gert Gremmen g.grem...@cetest.nl wrote (in oleokfnbajjejfkplbbmieoecdaa.g.grem...@cetest.nl) about 'Dwell time for Immunity under EN55024?' on Fri, 4 Oct 2002: Any deviation of the standard is doomed to art 10.2 , but changing an undefined dwell time to better meet the intention of the standard won't lead to a law suite. The first line is a very extreme view. According to UK sources (I am not allowed to say precisely who; no, I think that's daft, too), the standards route is OK IF the product DOES pass the standard when tested precisely to it. But the original test need NOT be precisely, or even approximately, to the standard . Several product type of standards do address the topic of dwell time btw. One never can get condamned by not following the prescriptions of the EMCD or standard, only by creating to much EMI or lacking susceptability (and other essential phenomenae). which is what GG seems to be saying here. Phenomenae! Make sure you keep all the test datae! And note down any formulaes you use in calculationses. (;-) -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
RE: Dwell time for Immunity under EN55024?
Hi Leslie, some answers: Is this called compliance testing or engineering verification? Anything that has to do with product quality (like EMI) needs to be addressed in terms of engineering. Can we do this and declare compliance? Sure you can declare compliance, as the European System is simply not targeted to complying with standards, but to complying with essential requirements. Of course you cannot declare compliance with the standard (to the letter). Using standards is just a way to presumption of compliance. Art 10.1 EMCD If you really DO deviate from the standard , you will need to follow the TCF route using a Competent Body to show compliance. Art 10.2 EMCD Any deviation of the standard is doomed to art 10.2 , but changing an undefined dwell time to better meet the intention of the standard won't lead to a law suite. Several product type of standards do address the topic of dwell time btw. One never can get condamned by not following the prescriptions of the EMCD or standard, only by creating to much EMI or lacking susceptability (and other essential phenomenae). Gert Gremmen ce-test -Original Message- From: Leslie Bai [mailto:leslie_...@yahoo.com] Sent: donderdag 3 oktober 2002 21:37 To: Gert Gremmen; paul_sc...@mitel.com; emc-p...@majordomo.ieee.org Subject: RE: Dwell time for Immunity under EN55024? Gert Gremmen wrote: ... prescan with Increase frequency step size ! (watch out for resonances) Modify equipment to decrease fault response time (low pass filters ; software ) Build Specifc test features Write specific test software . I am wondering whoelse out there doing these - Is that not sufficient to demonstrate conformity by follwoing standard procedures? What specific test features, what specific test software, are they specifed in the standards? Is this called compliance testing or engineering verification? Of course you will be violating the standard; Can we do this and declare compliance? Leslie Bai NARTE Certified Engineer (EMC-002112-NE) www.siemic.com -- Do you Yahoo!? New DSL Internet Access from SBC Yahoo!
Re: Dwell time for Immunity under EN55024?
I believe what Ing. Gremmen described is the true spirit of immunity testing - you must tailor the test technique to the characteristics of the test sample. As he noted, however, sometimes you have to modify the method of assessing compliant behavior in order to accomplish the test in a reasonable time period. This is all part of engineering, it is more than just lock-step response to standardized test procedures. -- From: Leslie Bai leslie_...@yahoo.com To: Gert Gremmen g.grem...@cetest.nl, paul_sc...@mitel.com, emc-p...@majordomo.ieee.org Subject: RE: Dwell time for Immunity under EN55024? List-Post: emc-pstc@listserv.ieee.org Date: Thu, Oct 3, 2002, 2:37 PM Gert Gremmen wrote: ... prescan with Increase frequency step size ! (watch out for resonances) Modify equipment to decrease fault response time (low pass filters ; software ) Build Specifc test features Write specific test software . I am wondering whoelse out there doing these - Is that not sufficient to demonstrate conformity by follwoing standard procedures? What specific test features, what specific test software, are they specifed in the standards? Is this called compliance testing or engineering verification? Of course you will be violating the standard; Can we do this and declare compliance? Leslie Bai NARTE Certified Engineer (EMC-002112-NE) www.siemic.com http://www.siemic.com Do you Yahoo!? New DSL Internet Access http://rd.yahoo.com/evt=1207/*http://sbc.yahoo.com/ from SBC Yahoo! http://rd.yahoo.com/evt=1207/*http://sbc.yahoo.com/
RE: Dwell time for Immunity under EN55024?
Gert Gremmen wrote: ... prescan with Increase frequency step size ! (watch out for resonances) Modify equipment to decrease fault response time (low pass filters ; software ) Build Specifc test features Write specific test software . I am wondering whoelse out there doing these - Is that not sufficient to demonstrate conformity by follwoing standard procedures? What specific test features, what specific test software, are they specifed in the standards? Is this called compliance testing or engineering verification? Of course you will be violating the standard; Can we do this and declare compliance? Leslie Bai NARTE Certified Engineer (EMC-002112-NE) www.siemic.com - Do you Yahoo!? New DSL Internet Access from SBC Yahoo!
Re: Dwell time for Immunity under EN55024?
I read in !emc-pstc that Gert Gremmen g.grem...@cetest.nl wrote (in oleokfnbajjejfkplbbmienmcdaa.g.grem...@cetest.nl) about 'Dwell time for Immunity under EN55024?' on Thu, 3 Oct 2002: The test will give you only PRESUMPTION of compliance anyway. It is extremely misleading to cast continual doubt on the standards route to compliance simply through hints about this word 'presumption'. The acceptance of a standard by CENELEC, by the Commission's EMC consultant and by the Commissioner's own staff, authorizing its notification in the OJEC, signifies that these experts consider that the standard IS SATISFACTORY for manufacturers to rely on, i.e. that it gives dependable evidence that the essential requirements are met. Wording in CENELEC and Commission documents that appear to 'water this down' are almost all covert (why?) references to the fact that adopted CISPR product-family standards deal only with emissions above 9 kHz, **and that EN61000-3-2, -3-, -11 (and -12 when it is published) that deal with emissions below 9 kHz**, have to be applied as well. It is extremely unfortunate that these words have been interpreted (sometimes for monetary gain) to mean that manufacturers have a duty to trawl though ALL published EMC standards, whether their scopes include the product in question or not, looking for additional tests and limits to apply. In the case of CISPR 14-1, the absence of limits for emissions in the UHF TV bands appears to be a serious defect, which should be dealt with under Article 8 of the Directive. It certainly seems surprising that no cases of, for example, small kitchen machines with commutator motors producing UHF TV interference, have been reported over the many years since CISPR14/EN55014 has been in place. Interference from such sources was the subject of the little-known (outside Europe) first EMC Directive, before the present one. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
RE: Dwell time for Immunity under EN55024?
Hi Paul, By reading your explanation it seems as if you miss the point of what immunity testing is about. Testing Immunity ! Your explanation makes me think you want to exercise the standard to the letter. That's probably not the case, but one should also take the following into account: Besides stpping/sweeping over the frequency range one needs to allow time to prove that the EUT does not respond unwantedly. This means that before even reading the standard, you need to know the equipment, define the equipments function (in terms of what immunity testing is about), define criteria of pass/fail and make an estimation of the required dwell time per step. This often leads to unrealistic long test times , because the required dwell time may be very long for some equipment. Then one should take measures to reduce test time to within the equipments life time. prescan with Increase frequency step size !(watch out for resonances) Modify equipment to decrease fault response time (low pass filters ; software ) Build Specifc test features Write specific test software . Of course you will be violating the standard; but if it's for Europe, no one cares, as you will prove to exercise due diligence The test will give you only PRESUMPTION of compliance anyway. Gert Gremmen ce-test, qualified testing -Original Message- From: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of paul_sc...@mitel.com Sent: donderdag 3 oktober 2002 00:54 To: emc-p...@majordomo.ieee.org Subject: Dwell time for Immunity under EN55024? Greetings, Problem: What is the correct dwell time to be used for radiated and conducted immunity for 61000-4-3/61000-4-6 under EN55024? My thoughts; Section 8 of IEC 61000-4-3 (I have 1995): The rate of sweep shall not exceed 1.5 x 10 -3 decades/s. I understand we shall not exceed a 1 % step size unles (as laid out in EN55024) we are prepared to increase our field strength. (We are not.) 1.5 milli decades per second = 667 seconds per decade. At 1% step size, there are 232 steps per decade. 667 seconds/232 steps = 2.87 seconds per step. Are there flaws in the above? Thanks in advance, Paul Scott --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
