Actually I had the same question as what Randy raised hear. I felt confused when trying to classify my EUT below 50W input power as Class A or Class D. Thanks for the clarification made by Gert. I was wondering why I could not have found the answer in Fig. 2 "Flow-chart for classification of equipment" in Page 10 of EN 61000-3-2.
"The current 3-2 is a very bad document,...", Gert Gremmen said. That is the most straitforward comment I've ever heard. "Nobody is perfect." Can we extend it to "No document is perfect."? But I still feel the law-making process in EMC world like something happened inside a much higher authority far far away from us. Is it possible to expedite the feedback process from ordinary EMC engineers? Barry Ma [email protected] ---------------- On Tue, 18 January 2000, "cetest" wrote: > I suppose Randy you are concerned about the EN-61000-3-2 instead of the > EN 61000-3-3 which is concerned with Flicker testing. > > Please Note that the 3-2 is currently under revision and prone to change > very soon ! > > I would select Scenario #1 > > The 50 watt limit is meant to be used for all equipment, and the current > document TC210-169 (in voting right now) has it's clause modified > as such. > > Strictly read you are right about the application of scenario #2. > > The current 3-2 is a very bad document, f.a. nothing is said about > test times and transitory effects. This will all or partly be covered > in the new version. > > BTW Using scenario #2 it will be hard to exceed any limit at all with an > active input power < 50 watt !!! > > Gert Gremmen > ce-test qualified testing > > > ============================== > http://www.cetest.nl > Do you know our > CE/E mark True type Font ? > http://www.cetest.nl/cettf.htm > ============================== > > >-----Original Message----- > >From: [email protected] [mailto:[email protected]] > >Sent: Tuesday, January 18, 2000 7:12 PM > >To: 'emc-pstc' > >Subject: Harmonics Testing > > > > > >Greetings EMC Professionals! > > > >I have a quick question regarding Harmonics testing to > >EN61000-3-3. We have an ITE product with a switching power > >supply. The product uses about 38 watts input power. According > >to the standard, which scenario applies? > > > >Scenario #1 > > > >The unit does not need to be tested, because it falls below the > >Class D Input power range of 75(50)W to 600W. Section 7.4 of the > >standard states that "...No limits apply for equipment with an > >active input power up to and including 75W...." > > > >Scenario #2 > > > >Since the unit does not use more than 75W (or more than 50W for > >that matter), the unit then defaults to the Class A requirements > >and therefor must meet the less stringent Class A limits. Section > >5 of EN61000-3-3 states: " Class A: Balanced 3-phase equipment > >AND ALL OTHER EQUIPMENT, except that stated [in Classes B-D]..." > > > >So I guess my question is this: when an ITE product with a > >switching power supply uses less than 50W (75w), does it become an > >exempt Class D Device, or doe sit become a Class A device? > > > >Your insights would be appreciated..... > > > > > >Regards, > > > > > >Randy Flinders > >Chairman > >Orange County Chapter > >IEEE EMC Society > >[email protected] > >(714) 513-8012 > >(714) 513-8265 Fax > > > >Note: The opinions expressed herein are personal and in no way > >represent the position of the IEEE, The EMC Society, or my employer. > > ______________________________________________________________ Free Internet Access from AltaVista: Get it, share it & win! http://freeaccess.altavista.com/pika/www/initweb.jsp --------- This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to [email protected] with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to [email protected], [email protected], [email protected], or [email protected] (the list administrators).
