Re: CE test suite for computers
I read in !emc-pstc that George, David L george.da...@unisys.com wrote (in 3B10FF0A008FF6458711E6E375E830412C16A6@USTR- EXCH2.na.uis.unisys.com) about 'CE test suite for computers', on Mon, 27 Aug 2001: John: After all your years on the committee and having heard all the technical arguments, I am surprised the committee is still trying to justify the additional costs on each product? If the power system is so bad it can be fixed cheaply for the consumer once and for 30+ years by changing the infrastructure. No electronic product lasts 30 years and the cost is multiplied each time it is replaced. Well, of course I am aware of your views and that particular economic point. No doubt it will be taken into account by IEC SC77A/WG1/TF5a, on which the ESI experts are in the minority. The bottom line is data now proves the European power system is very good I am also aware of that data collection exercise, which indeed is strong evidence. OTOH, I have the evidence of my own eyes and measurements here. The mains waveform is very visibly 'flat-topped' and the THD exceeds 4% on occasions (summer Sunday evenings, when almost all the load is TV sets and home PCs; we still have very few home air- conditioners). With regard to voltage changes and flicker, my own experience is that DIY arc-welders can be a problem, but I don't see much problem with anything else. This is largely reflected in the relaxed limits in the still-unpublished (and largely unpublicised) 'other' Millennium Amendment - to IEC/EN61000-3-3. and these two standards are unnecessary but the standards makers (power utility people) As I wrote above, the ESI people are now in the minority of *attendees* at the relevant meetings; they also point out that according to the *membership lists* they have always been in the minority compared to experts from equipment manufacturing, but not all members attended the meetings before 1998, when IEC/TC74 realised what was happening, as I realised in 1991. still insist in spite of proof, their systems are not so good. In their view this is why we need limits on products and the power distribution system need not be fixed. There is also a major problem at political level, insofar as all the ESI companies in European countries where the system has been, or will be, privatized, are subject to very strict (and somewhat uninformed) financial control by government Regulators. The ESI is not being allowed to finance its own harmonic mitigation, except in unusual circumstances. Information has come to hand that these Regulators are not even in favour of site-level harmonic mitigation, partly in case it allows some 'polluter' to avoid paying for the 'pollution', and regard equipment- level control as the Only Solution. Compared with this mantra-oriented attitude, the ESI people are pussy-cats (now!). -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Eat mink and be dreary! --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net 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: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: CE test suite for computers
John: After all your years on the committee and having heard all the technical arguments, I am surprised the committee is still trying to justify the additional costs on each product? If the power system is so bad it can be fixed cheaply for the consumer once and for 30+ years by changing the infrastructure. No electronic product lasts 30 years and the cost is multiplied each time it is replaced. The bottom line is data now proves the European power system is very good and these two standards are unnecessary but the standards makers (power utility people) still insist in spite of proof, their systems are not so good. In their view this is why we need limits on products and the power distribution system need not be fixed. Dave George, Former WG1 member Unisys Standards Management Malvern, PA Net: 385-3653 Fax: 610-695-4700 -Original Message- From: John Woodgate [mailto:j...@jmwa.demon.co.uk] Sent: Saturday, August 18, 2001 1:55 PM To: emc-p...@majordomo.ieee.org Subject: Re: CE test suite for computers I read in !emc-pstc that Tania Grant taniagr...@msn.com wrote (in oe127msph2q6dqajy4k4...@hotmail.com) about 'CE test suite for computers', on Sat, 18 Aug 2001: Most people will never understand anything unless it is explained to them. Merely stating that the power distribution in Europe and America is not the same, is not an explanation but could even be construed as a lofty put-down. I think one would have to be touchy to regard it as a put-down. I admit to some exasperation, in that members of IEC SC77A/WG1 and WG2, especially the US and Canadian experts, have been working hard to convince their professional colleagues that the European requirements on harmonic current and voltage-change emissions are *fairly* soundly- based, not inventions of the Devil. Had the European electricity supply industry been a little less secretive, and offered more comprehensive explanations for the need for emission control, much of the controversy of the last 10 years might have been avoided. If anyone out there can explain the difference between American and European power distribution, and why harmonics are not such a big problem in the U.S., I am sure that many of us will be extremely grateful. Well, it isn't a big secret but it isn't common knowledge in the Americas. I feel sure that much more exhaustive explanations than that offered below can be found by a web search. Several US and Canada-based academics have written on the subject. Briefly, in the Americas, power is distributed at Medium Voltage to points very close to where it is used, and transformers of no more than a few tens of kVA rating deliver Low Voltage, 220 V centre-grounded, to residential and light industrial users. The transformer impedances are lower than is usual in Europe, even allowing for the voltage differences. The MV network impedances are also lower than in Europe. Because the supply impedances are lower, a given amount of harmonic current produces less voltage distortion, and that is what tends to cause adverse effects, except 'hot neutrals' due to triplen harmonic addition in the neutral conductors of 3-phase 4-wire systems. Because the supply impedances are lower, and fewer users are fed from each transformer, voltage-changes due to rapidly-varying load currents are smaller and affect fewer users. 120 V lamps have thicker filaments and flicker less for a given transient voltage change. All this is being studied and documented by the above-mentioned IEC WGs, and improved standards, and other types of publication, will result in due course. In Europe, up to typically 500 residential and light industrial users are supplied from one 500 kVA or larger transformer, so the LV cable runs are much longer than in the American system, and deliver nominally 230 V single- or 3-phase (230 V phase voltage), with wired neutral. The way that the neutral is grounded differs between European countries: France, UK and Norway use systems that are not like the US system, whereas other countries' systems are more similar. The MV network impedance is quite high (maybe over 15%), necessitated, AIUI, by fault- level requirements which I personally have not studied in detail. And can someone explain to me why the European Community is adopting the American Energy Star Program? -- Albeit rendered in their own language! No-one knows why the EC does anything. (;-) -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co..uk Eat mink and be dreary! --- 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: Michael
RE: CE test suite for computers
Don't forget Telco Conducted Emissions is NOT required until at least 2003' Richard, -Original Message- From: Frazee, Douglas (Douglas) [mailto:dfra...@lucent.com] Sent: Friday, August 17, 2001 12:19 PM To: 'Pettit, Ghery'; 'Stuart Lopata'; emc Subject: RE: CE test suite for computers Ghery, I believe 61000-3-2, Class D is also required. Doug Frazee Regulatory Compliance Manager Lucent Technologies, Broadband Carrier Networks Access Technology Division InterNetworking Systems (301) 809-4415 (301) 352-4730 FAX dfra...@lucent.com -Original Message- From: Pettit, Ghery [mailto:ghery.pet...@intel.com] Sent: Thursday, August 16, 2001 4:39 PM To: 'Stuart Lopata'; emc Subject: RE: CE test suite for computers Stuart, For ITE the requirements are EN 55022:1994 (through 1 August 2003) and EN 55024:1998. If you wish to test to anything else, you need to go through a Competent Body and convince them that the alternate standards are adequate. Ghery Pettit Intel -Original Message- From: Stuart Lopata [mailto:stu...@timcoengr.com] Sent: Thursday, August 16, 2001 12:14 PM To: emc Subject: CE test suite for computers Any info about the test suite for computers (for commercial professional markets in EU) to meet the EMC directive for the CE mark? Also wondering if there is any collection of non-harmonized standards that are currently accepted for CE mark testing? to my knowledge, EMC testing for computers requires the following. (so far) EN 55022 for ITE equipment EN 61000 3-1 through 3-11 Sincerely, Stuart Lopata
Re: CE test suite for computers
I read in !emc-pstc that Tania Grant taniagr...@msn.com wrote (in oe67wwnyumtlor31l1g0002c...@hotmail.com) about 'CE test suite for computers', on Sat, 18 Aug 2001: Thank you, Mr. Woodgate, I am sure many of the American contingent are grateful for your explanation. I note the tone of your remarks, but I hope, nevertheless that your second sentence is true. Rich Nute says 'the problems are the same in USA and Europe' and I say 'they are different'. We are both right: the same harmonic emissions occur everywhere, but they don't excite most American electricity suppliers (Hydro Quebec is an exception), whereas in Europe they do excite, and the excitement is not entirely groundless. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co..uk Eat mink and be dreary! --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net 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://www.rcic.com/ click on Virtual Conference Hall,
Fw: CE test suite for computers
- Original Message - From: Chris Wells To: Tania Grant Sent: Saturday, August 18, 2001 10:54 PM Subject: Re: CE test suite for computers Jumping into the middle of this... In Europe there are a lot of older buildings with half sized neutrals relative to the supply phases. In the USA we tend to have newer designs and tend to have at least neutral circuits = to the phase circuits. In newer buildings we are pushing for 200% neutrals. This is all due to the effect of single phase loads and the tripplen harmonics they create. The 3, 9 etc do not cancel on the neutral- they tripple up on the neutral causing large harmonic loads. This can cause voltage drops on the phases and over heating of the neutrals - even fires. I assume this is why Europe is pushing for PFC front ends on Power supplies above 50 or is it 75W? The PFC front end does correct Power Factor, but more importantly it pulls current closer to a 50 or 60 Hz sinusoide. It eliminates much of the lower harmonics with distortion only showing up at the higher harmonics like the 27th or higher. At that point the THD levels are very low and insignificant. Is this related to the Energy STar Program - I have no idea. Hope this makes some sense relative to the disscussion :-) Regards Chris Wells Senior Design Engineer Cutler-hammer well...@eaton.com - Original Message - From: Tania Grant To: John Woodgate ; emc-p...@majordomo.ieee.org Sent: Saturday, August 18, 2001 12:32 PM Subject: Re: CE test suite for computers Dear Mr. Woodgate, Most people will never understand anything unless it is explained to them. Merely stating that the power distribution in Europe and America is not the same, is not an explanation but could even be construed as a lofty put-down. If anyone out there can explain the difference between American and European power distribution, and why harmonics are not such a big problem in the U.S., I am sure that many of us will be extremely grateful. And can someone explain to me why the European Community is adopting the American Energy Star Program?-- Albeit rendered in their own language! taniagr...@msn.com - Original Message - From: John Woodgate Sent: Friday, August 17, 2001 3:37 PM To: emc-p...@majordomo.ieee.org Subject: Re: CE test suite for computers I read in !emc-pstc that Pettit, Ghery ghery.pet...@intel.com wrote (in d5e932f578ebd111ac3f00a0c96b1e6f09506...@orsmsx31.jf.intel.com) about 'CE test suite for computers', on Fri, 17 Aug 2001: Also EN 61000-3-3 needs to be considered. Useless standards, if you ask me. That's because you, like most Americans, do not understand the problems in Europe. Because the power distribution networks in Europe and the Americas are very differently configured, you have far fewer problems with harmonics and voltage changes, and voltage changes seem to be much more tolerated, in USA anyway. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Eat mink and be dreary! --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net 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://www.rcic.com/ click on Virtual Conference Hall,
Re: CE test suite for computers
Thank you, Mr. Woodgate, I am sure many of the American contingent are grateful for your explanation. taniagr...@msn.com - Original Message - From: John Woodgate Sent: Saturday, August 18, 2001 3:25 PM To: emc-p...@majordomo.ieee.org Subject: Re: CE test suite for computers I read in !emc-pstc that Tania Grant taniagr...@msn.com wrote (in oe127msph2q6dqajy4k4...@hotmail.com) about 'CE test suite for computers', on Sat, 18 Aug 2001: Most people will never understand anything unless it is explained to them. Merely stating that the power distribution in Europe and America is not the same, is not an explanation but could even be construed as a lofty put-down. I think one would have to be touchy to regard it as a put-down. I admit to some exasperation, in that members of IEC SC77A/WG1 and WG2, especially the US and Canadian experts, have been working hard to convince their professional colleagues that the European requirements on harmonic current and voltage-change emissions are *fairly* soundly- based, not inventions of the Devil. Had the European electricity supply industry been a little less secretive, and offered more comprehensive explanations for the need for emission control, much of the controversy of the last 10 years might have been avoided. If anyone out there can explain the difference between American and European power distribution, and why harmonics are not such a big problem in the U.S., I am sure that many of us will be extremely grateful. Well, it isn't a big secret but it isn't common knowledge in the Americas. I feel sure that much more exhaustive explanations than that offered below can be found by a web search. Several US and Canada-based academics have written on the subject. Briefly, in the Americas, power is distributed at Medium Voltage to points very close to where it is used, and transformers of no more than a few tens of kVA rating deliver Low Voltage, 220 V centre-grounded, to residential and light industrial users. The transformer impedances are lower than is usual in Europe, even allowing for the voltage differences. The MV network impedances are also lower than in Europe. Because the supply impedances are lower, a given amount of harmonic current produces less voltage distortion, and that is what tends to cause adverse effects, except 'hot neutrals' due to triplen harmonic addition in the neutral conductors of 3-phase 4-wire systems. Because the supply impedances are lower, and fewer users are fed from each transformer, voltage-changes due to rapidly-varying load currents are smaller and affect fewer users. 120 V lamps have thicker filaments and flicker less for a given transient voltage change. All this is being studied and documented by the above-mentioned IEC WGs, and improved standards, and other types of publication, will result in due course. In Europe, up to typically 500 residential and light industrial users are supplied from one 500 kVA or larger transformer, so the LV cable runs are much longer than in the American system, and deliver nominally 230 V single- or 3-phase (230 V phase voltage), with wired neutral. The way that the neutral is grounded differs between European countries: France, UK and Norway use systems that are not like the US system, whereas other countries' systems are more similar. The MV network impedance is quite high (maybe over 15%), necessitated, AIUI, by fault- level requirements which I personally have not studied in detail. And can someone explain to me why the European Community is adopting the American Energy Star Program?-- Albeit rendered in their own language! No-one knows why the EC does anything. (;-) -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co..uk Eat mink and be dreary! --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net 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://www.rcic.com/ click on Virtual Conference Hall,
Re: CE test suite for computers
Rich, Thank you very very much. taniagr...@msn.com - Original Message - From: Rich Nute Sent: Saturday, August 18, 2001 3:02 PM To: taniagr...@msn.com Cc: j...@jmwa.demon.co.uk; emc-p...@majordomo.ieee.org Subject: Re: CE test suite for computers Hi John and Tania: Actually, the harmonic current problem is no different between Europe and North America. The basic problem is that the harmonic currents generated in the load equipment are dissipated in the delta primary of a delta-wye distribution transformer. If the harmonic content is large, then the primary winding can overheat, resulting in transformer failure. In North America, distribution transformers are relatively small. Three-phase is not used in the home, so the problem only shows up in commercial and industrial sites. The distribution transformers are largely owned by the business, not by the power company. North America has incurred such transformer failures. The problem has been publicised, and transformers are now designed using a K factor which indicates how much harmonic current the transformer can safely handle. In Europe, the distribution transformers are relatively large. Three-phase is distributed to homes. A single transformer can supply up to 600 homes and businesses. (In North America, the transformer supplies 8 homes maximum.) It is relatively rare for the business to own the distribution transformer. Failure of such a transformer can be quite disruptive. So, in Europe, rather than replace the very large distribution transformers, the power supply industry is imposing harmonic current emission limits on electrical products. Harmonic currents can cause other problems. But, this is my understanding of the reason behind EN 6100-3-2. Best regards, Rich --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net 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://www.rcic.com/ click on Virtual Conference Hall,
Re: CE test suite for computers
The problem I have seen is related to harmonic current, but really is more easily understood in the time domain. Electronic power supplies, either linear or switched, draw large slugs of current when 50/60 Hz filter capacitor potentials drop two diode drops below line potential, at which time these diodes switch on to replenish the capacitor. Without special circuitry, this happens exclusively at the peak bus potential, meaning that the current waveform drawn from the bus is a very large spike occurring only at the time the ac potential crests. The effect is to flatten the sinusoidal shape of the bus waveform. Many years ago I started out working near the center of one office building relatively near the breaker panel. Over time my cubicle moved and I was closer to the end of the building. The power supply of my desktop was controlled from a soft key on my keyboard. As I moved from building center, I found that it was harder and harder to get my computer to turn on. That's when I measured line potentials with my scope and found that the further I was from building center the flatter the line potential was, and the lower the peak. Of course that is merely an empirical observation and not a proven cause and effect. -- From: Rich Nute ri...@sdd.hp.com To: taniagr...@msn.com Cc: j...@jmwa.demon.co.uk, emc-p...@majordomo.ieee.org Subject: Re: CE test suite for computers Date: Sat, Aug 18, 2001, 4:10 PM Hi John and Tania: Actually, the harmonic current problem is no different between Europe and North America. The basic problem is that the harmonic currents generated in the load equipment are dissipated in the delta primary of a delta-wye distribution transformer. If the harmonic content is large, then the primary winding can overheat, resulting in transformer failure. In North America, distribution transformers are relatively small. Three-phase is not used in the home, so the problem only shows up in commercial and industrial sites. The distribution transformers are largely owned by the business, not by the power company. North America has incurred such transformer failures. The problem has been publicised, and transformers are now designed using a K factor which indicates how much harmonic current the transformer can safely handle. In Europe, the distribution transformers are relatively large. Three-phase is distributed to homes. A single transformer can supply up to 600 homes and businesses. (In North America, the transformer supplies 8 homes maximum.) It is relatively rare for the business to own the distribution transformer. Failure of such a transformer can be quite disruptive. So, in Europe, rather than replace the very large distribution transformers, the power supply industry is imposing harmonic current emission limits on electrical products. Harmonic currents can cause other problems. But, this is my understanding of the reason behind EN 6100-3-2. Best regards, Rich --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net 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://www.rcic.com/ click on Virtual Conference Hall, --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net 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://www.rcic.com/ click on Virtual Conference Hall,
Re: CE test suite for computers
I read in !emc-pstc that Rich Nute ri...@sdd.hp.com wrote (in 200108182110.oaa02...@epgc196.sdd.hp.com) about 'CE test suite for computers', on Sat, 18 Aug 2001: The basic problem is that the harmonic currents generated in the load equipment are dissipated in the delta primary of a delta-wye distribution transformer. If the harmonic content is large, then the primary winding can overheat, resulting in transformer failure. In Europe, that isn't usually the major problem. System capacitor overheating due to harmonic currents is more significant. In some cases, system inductors have failed due to over-voltage. Unfortunately, the European supply industry only cites extreme cases (like a 1MW motor!), and then only grudgingly. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Eat mink and be dreary! --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net 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://www.rcic.com/ click on Virtual Conference Hall,
Re: CE test suite for computers
I read in !emc-pstc that Tania Grant taniagr...@msn.com wrote (in oe127msph2q6dqajy4k4...@hotmail.com) about 'CE test suite for computers', on Sat, 18 Aug 2001: Most people will never understand anything unless it is explained to them. Merely stating that the power distribution in Europe and America is not the same, is not an explanation but could even be construed as a lofty put-down. I think one would have to be touchy to regard it as a put-down. I admit to some exasperation, in that members of IEC SC77A/WG1 and WG2, especially the US and Canadian experts, have been working hard to convince their professional colleagues that the European requirements on harmonic current and voltage-change emissions are *fairly* soundly- based, not inventions of the Devil. Had the European electricity supply industry been a little less secretive, and offered more comprehensive explanations for the need for emission control, much of the controversy of the last 10 years might have been avoided. If anyone out there can explain the difference between American and European power distribution, and why harmonics are not such a big problem in the U.S., I am sure that many of us will be extremely grateful. Well, it isn't a big secret but it isn't common knowledge in the Americas. I feel sure that much more exhaustive explanations than that offered below can be found by a web search. Several US and Canada-based academics have written on the subject. Briefly, in the Americas, power is distributed at Medium Voltage to points very close to where it is used, and transformers of no more than a few tens of kVA rating deliver Low Voltage, 220 V centre-grounded, to residential and light industrial users. The transformer impedances are lower than is usual in Europe, even allowing for the voltage differences. The MV network impedances are also lower than in Europe. Because the supply impedances are lower, a given amount of harmonic current produces less voltage distortion, and that is what tends to cause adverse effects, except 'hot neutrals' due to triplen harmonic addition in the neutral conductors of 3-phase 4-wire systems. Because the supply impedances are lower, and fewer users are fed from each transformer, voltage-changes due to rapidly-varying load currents are smaller and affect fewer users. 120 V lamps have thicker filaments and flicker less for a given transient voltage change. All this is being studied and documented by the above-mentioned IEC WGs, and improved standards, and other types of publication, will result in due course. In Europe, up to typically 500 residential and light industrial users are supplied from one 500 kVA or larger transformer, so the LV cable runs are much longer than in the American system, and deliver nominally 230 V single- or 3-phase (230 V phase voltage), with wired neutral. The way that the neutral is grounded differs between European countries: France, UK and Norway use systems that are not like the US system, whereas other countries' systems are more similar. The MV network impedance is quite high (maybe over 15%), necessitated, AIUI, by fault- level requirements which I personally have not studied in detail. And can someone explain to me why the European Community is adopting the American Energy Star Program? -- Albeit rendered in their own language! No-one knows why the EC does anything. (;-) -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co..uk Eat mink and be dreary! --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net 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://www.rcic.com/ click on Virtual Conference Hall,
Re: CE test suite for computers
I read in !emc-pstc that Rich Nute ri...@sdd.hp.com wrote (in 200108171905.maa00...@epgc196.sdd.hp.com) about 'CE test suite for computers', on Fri, 17 Aug 2001: Agreed! Well, see my direct response to G. P. EN 61000-3-2 is driven by Euro power distributors who don't want to correct for non-linear loads. (But who have no quarrel with correcting for phase angle.) That's because it's practicable to correct for phase angle but it is not practicable (yet) to correct for harmonics at system level. Electricité de France has one of the first experimental system-level compensators now under trial. I don't understand the drive for EN 61000-3-3. See my comments about voltage change tolerance in my other post. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co..uk Eat mink and be dreary! --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net 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://www.rcic.com/ click on Virtual Conference Hall,
Re: CE test suite for computers
I read in !emc-pstc that Pettit, Ghery ghery.pet...@intel.com wrote (in d5e932f578ebd111ac3f00a0c96b1e6f09506...@orsmsx31.jf.intel.com) about 'CE test suite for computers', on Fri, 17 Aug 2001: Also EN 61000-3-3 needs to be considered. Useless standards, if you ask me. That's because you, like most Americans, do not understand the problems in Europe. Because the power distribution networks in Europe and the Americas are very differently configured, you have far fewer problems with harmonics and voltage changes, and voltage changes seem to be much more tolerated, in USA anyway. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co..uk Eat mink and be dreary! --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net 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://www.rcic.com/ click on Virtual Conference Hall,
Re: CE test suite for computers
Hi Ghery: Also EN 61000-3-3 needs to be considered. Useless standards, if you ask me. Agreed! EN 61000-3-2 is driven by Euro power distributors who don't want to correct for non-linear loads. (But who have no quarrel with correcting for phase angle.) I don't understand the drive for EN 61000-3-3. Best regards, Rich --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net 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://www.rcic.com/ click on Virtual Conference Hall,
RE: CE test suite for computers
Also EN 61000-3-3 needs to be considered. Useless standards, if you ask me. Ghery -Original Message- From: Frazee, Douglas (Douglas) [mailto:dfra...@lucent.com] Sent: Friday, August 17, 2001 9:19 AM To: 'Pettit, Ghery'; 'Stuart Lopata'; emc Subject: RE: CE test suite for computers Ghery, I believe 61000-3-2, Class D is also required. Doug Frazee Regulatory Compliance Manager Lucent Technologies, Broadband Carrier Networks Access Technology Division InterNetworking Systems (301) 809-4415 (301) 352-4730 FAX dfra...@lucent.com -Original Message- From: Pettit, Ghery [mailto:ghery.pet...@intel.com] Sent: Thursday, August 16, 2001 4:39 PM To: 'Stuart Lopata'; emc Subject: RE: CE test suite for computers Stuart, For ITE the requirements are EN 55022:1994 (through 1 August 2003) and EN 55024:1998. If you wish to test to anything else, you need to go through a Competent Body and convince them that the alternate standards are adequate. Ghery Pettit Intel -Original Message- From: Stuart Lopata [mailto:stu...@timcoengr.com] Sent: Thursday, August 16, 2001 12:14 PM To: emc Subject: CE test suite for computers Any info about the test suite for computers (for commercial professional markets in EU) to meet the EMC directive for the CE mark? Also wondering if there is any collection of non-harmonized standards that are currently accepted for CE mark testing? to my knowledge, EMC testing for computers requires the following. (so far) EN 55022 for ITE equipment EN 61000 3-1 through 3-11 Sincerely, Stuart Lopata
RE: CE test suite for computers
Ghery, I believe 61000-3-2, Class D is also required. Doug Frazee Regulatory Compliance Manager Lucent Technologies, Broadband Carrier Networks Access Technology Division InterNetworking Systems (301) 809-4415 (301) 352-4730 FAX dfra...@lucent.com -Original Message- From: Pettit, Ghery [mailto:ghery.pet...@intel.com] Sent: Thursday, August 16, 2001 4:39 PM To: 'Stuart Lopata'; emc Subject: RE: CE test suite for computers Stuart, For ITE the requirements are EN 55022:1994 (through 1 August 2003) and EN 55024:1998. If you wish to test to anything else, you need to go through a Competent Body and convince them that the alternate standards are adequate. Ghery Pettit Intel -Original Message- From: Stuart Lopata [mailto:stu...@timcoengr.com] Sent: Thursday, August 16, 2001 12:14 PM To: emc Subject: CE test suite for computers Any info about the test suite for computers (for commercial professional markets in EU) to meet the EMC directive for the CE mark? Also wondering if there is any collection of non-harmonized standards that are currently accepted for CE mark testing? to my knowledge, EMC testing for computers requires the following. (so far) EN 55022 for ITE equipment EN 61000 3-1 through 3-11 Sincerely, Stuart Lopata
Re: CE test suite for computers
I read in !emc-pstc that Stuart Lopata stu...@timcoengr.com wrote (in 00d301c12687$8b6e8100$1301a8c0@newberry) about 'CE test suite for computers', on Thu, 16 Aug 2001: Any info about the test suite for computers (for commercial professional markets in EU) to meet the EMC directive for the CE mark? Also wondering if there is any collection of non-harmonized standards that are currently accepted for CE mark testing? to my knowledge, EMC testing for computers requires the following. (so far) EN 55022 for ITE equipment EN 61000 3-1 through 3-11 Certainly NOT 'EN61000-3-1 through 11'. For desktop computers, you need to meet EN61000-3-2 (Class D limits) and EN61000-3-3. If your computers are rated at more than 16A/phase, then EN61000-3-11 and EN61000-3-12 apply INSTEAD, but -12 hasn't been published yet so you don't have to comply with any limits. -11 and -12 supersede -5 and -4, which are IEC Reports, not adopted as ENs and could only be applied (if you were totally insane!) in the context of a Technical Construction File. -11 is, and -12 will be, far more realistic. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Eat mink and be dreary! --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net 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://www.rcic.com/ click on Virtual Conference Hall,
RE: CE test suite for computers
Stuart, For ITE the requirements are EN 55022:1994 (through 1 August 2003) and EN 55024:1998. If you wish to test to anything else, you need to go through a Competent Body and convince them that the alternate standards are adequate. Ghery Pettit Intel -Original Message- From: Stuart Lopata [mailto:stu...@timcoengr.com] Sent: Thursday, August 16, 2001 12:14 PM To: emc Subject: CE test suite for computers Any info about the test suite for computers (for commercial professional markets in EU) to meet the EMC directive for the CE mark? Also wondering if there is any collection of non-harmonized standards that are currently accepted for CE mark testing? to my knowledge, EMC testing for computers requires the following. (so far) EN 55022 for ITE equipment EN 61000 3-1 through 3-11 Sincerely, Stuart Lopata
