I read in !emc-pstc that Rich Nute <[email protected]> wrote (in <[email protected]>) about 'EN 61000-3-2:2000' on Mon, 10 Nov 2003: > > > >Hi John: > > >> >Some have questioned whether 61000-3-2 is even an EMC standard! >> >> If not, what do you think it is? > >I fall into the group that question whether 61000-3-2 >is an EMC -- Electo-Magnetic Compatibility -- standard. > >The objective is to prevent reduction of peak voltage >on the public supply mains (in Europe) due to rectifier >and similar non-linear loads.
No, it isn't. Limits are applied to things such as dimmers and CFLs, which specifically do not flatten the peaks. > >The method chosen is to require all loads to be near- >linear. Not at all: the Class A limits allow substantial harmonic currents, and the Class B limits allow even more. > >I suppose this is a compatibility issue -- a compatibility >between the source and the load. > >And, it is electrical. So? > >And, one can consider the harmonic content of the current >waveform as being an emission from the product. Indeed. > >But, this is purely a current emission. It is not measured >with a receiver as are the other 61000-series emissions. The IEC/EN 61000-4-7 instrument can certainly be regarded as a receiver. There are receivers and receivers: you wouldn't want to listen to the radio on a CISPR 16-1 instrument. >Unlike radio-frequency emissions, incompatiblity affects >no one but the electricity supplier. (Don't argue that >other users on the public supply are affected; this is >only true if the electricity supplier does nothing at >his end.) I'll argue how I choose. Network-level harmonic mitigation is an exceedingly difficult and costly technique. Harmonics DO affect load equipment such as motors. > >Non-linear current is not at all similar to the electo- >magnetic emissions issue addressed by the other standards >in the 61000-series. One can also argue that sinusoidal radiated emissions are different from broad-band emissions. So what? > >If harmonic currents are an EMC issue, then so, too, is >x-radiation from cathode-ray tubes -- which is a MUCH >closer fit. Why isn't x-radiation emission included in >the 61000-series? Because it's covered by other standards, such as 60065. > Or laser emissions? Covered by 60825. >Both of these are >much better fits to the 61000-series than is a non-linear >current. I don't see that they are. Although 'electromagnetic', the difference in frequencies demands totally different technologies, to deal with the totally different physical effects. > >Lastly, this is a Euro-centric issue, not a world-wide >issue. It shouldn't be in the IEC scheme. No, it isn't. Several countries, including Japan, are adopting harmonic emission controls, based on 61000-3-2. > >Next thing that will happen is that the 61000-series will >include requirements against voltage emission (voltage on >accessible parts) to achieve compatiblity with people to >prevent electric shock! EMC!!! No, that is covered by other standards. > >:-) > >61000-3-2 should be a stand-alone standard. But, if it >was a stand-alone standard, there would be no Directive >behind it to enforce it. It replaced IEC/EN 60555-2, which was notified under the EMC Directive before it was withdrawn. The '61000-' designation is quite irrelevant. > So, in a self-indulging mode, Who or what is 'self-indulging'? >and by stretching the definition of EMC, 61000-3-2 is >enforced by the EMC Directive. That is why it is an >EMC standard. > I don't think I understand that. And your arguments seem to stem from a lack of familiarity with the subject anyway. -- 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: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: [email protected] Dave Heald: [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
