I'd like to present a dissenting opinion on this one. I feel that, as the standard is written now, Class A test and measurement equipment complying to EN 61326-1 is exempt from the harmonics and flicker standards of EN 61000-3-2 and EN 61000-3-3.
I don't feel as if it was overlooked by EN 61326-1. How could that be? It was specifically listed for Class B equipment (see Table 4, Page 14). I then assume that it was explicitly omitted for Class A equipment (see Table 3, Page 14). I just can't believe that the commitee working on the standard just plain forgot to include it in the Class A emissions requirements. My assumption is that they know the scope of EN 61000-3-2 and EN 61000-3-3 better than I. My understanding of the scope of EN 61000-3-2 and EN 61000-3-3 is that it is targeting Information Technology Equipment (ITE). Much of the equipment under EN 61326-1 is not ITE. I believe that there is a solid foundation for this reasoning. Harmonic and Flicker standards were written because equipment with poor power factors and or large in-rush currents were drawing disproportionately large peak currents. These fast moving, high amplitude current peaks can cause voltage dips in the power grid and can cause harmonic currents (currents whose fundamental frequency is a multple of the power grid frequency) in capacitors of other devices connected to the same power grid. It's physical fact that these voltage dips and harmonic currents can hurt other devices connected to the power grid. The initial Harmonic and Flicker standards set by IEC (IEC 555-2 and 555-3) included equipment drawing more than 16A of current per phase because IEC thought that it took at least 16A of un-powerfactor-corrected (my own word) nominal current draw, per phase, to have a detrimental effect. It's my belief that the new standards (EN 61000-3-2 and EN 61000-3-3) lowered the current draw limitation because of the cumulative effect of numerous pieces of ITE equipment connected to the same grid. For instance, in my office, we have 100 computers (ITE equipment). If all of these computers did not have power factor correction, we could have some serious harmonic current draw. EN 61326-1 covers a great deal of equipment that is not ITE equipment. As such, I don't think that the scope of EN 61000-3-2 and EN 61000-3-3 supercedes or overlaps the scope of EN 61326-1. The great thing about this forum is that, if I'm wrong in this, I hope that someone can point out my error and back it up with some tangible evidence. If I'm wrong, I'd really like to know. I don't want cause my company to be seduced by the "dark side" of non-compliance. Chris Maxwell, Design Engineer GN Nettest Optical Division 109 N. Genesee St. Utica, NY 13502 PH: 315-797-4449 FAX: 315-797-8024 EMAIL: [email protected] > -----Original Message----- > From: Barry Ma [SMTP:[email protected]] > Sent: Monday, March 27, 2000 12:10 PM > To: [email protected]; [email protected] > Cc: [email protected] > Subject: RE: EN61326-1 Harmonics > > > Hi Brian, > > Here is my $0.02. > (1) As far as EN61326-1 is concerned, Class A is not required to pass > EN61000-3-2 and EN61000-3-3. Because EN61326 committee treated these two > standards as basic standards. > (2) However, they are not basic standards. They are product standards. If > your product falls under their definition the product MUST comply with > them no matter whether EN61326 calls for them. > (3) Therefore, we found a conflict between 61326 and 61000-3-2/3 (although > they are all listed in harmonized standards). How to solve the conflict? > There might be two options. > (A) Change 61326: Class A is also required to pass EN61000-3-2 and > -3. > (B) Change 61000-3-2/3: They are basic standards. (the same as > 61000-4-X series). > > Best Regards, > Barry Ma > [email protected] > -------------- > On Fri, 24 March 2000, "Provost,Norm" wrote: > > > The exclusion of harmonic test requirements in EN 61326 for equipment > which > > need only meet Class A emission limits was a deliberate decision by the > > authors. It was not an omission by error. Many outside the committee > now > > view this decision as a "mistake". > > > > There is no revision in progress. > > > > Best Regards, > > Norm Provost > > > -----Original Message----- > > > From: Brian Kunde [SMTP:[email protected]] > > > Sent: Friday, March 24, 2000 12:16 PM > > > To: 'IEEE EMC/PS Group' > > > Subject: EMC: EN61326-1 Harmonics > > > > > > The EN 61326-1 family standard for laboratory equipment only lists > Harmonic > > > testing as a requirement for Class B environments. So Class A products > are > > > not required to pass the harmonics tests (flicker too). > > > > > > Is this going to continue as the rule in the future? Will this rule > carry > > > over to other family and generic standards? > > > > > > I had heard that omitting harmonic testing in a class A environment > was a > > > mistake and that it will be corrected on future versions of the > standard. > > > Can anyone validate or invalidate this statement. > > > > > > Thanks, > > > Brian > > > ____________________________________________________________________ > > For the largest MP3 index on the Web, go to http://mp3.altavista.com > > ____________________________________________________________________ > > > ------------------------------------------- > This message is from the IEEE EMC Society Product Safety > Technical Committee emc-pstc discussion list. > > To cancel your subscription, send mail to: > [email protected] > with the single line: > unsubscribe emc-pstc > > For help, send mail to the list administrators: > Jim Bacher: [email protected] > Michael Garretson: [email protected] > > For policy questions, send mail to: > Richard Nute: [email protected] > ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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