Re: EN55024 & 55022 my 2p..
Hello, Just want to throw my 2p --ooops 2c in. This issue ( of ITE universally being Class B ) is not new. It started way before 1995 when the generic standards were released mandating that all equipment NOT tested to the heavy immunity should be tested to Class B emissions. I remember distinctly then a shiver going up and down my spine!! You see, unlike the very ordered and structured approach of the FCC who defined emissions limits to whom you were selling - the EU regulators decided to define the emissions limits based on installation. In the US that might be one and the same - after all, who lives in a factory. In Europe the situation is not so clear. It is perfectly possible for folks to live cheek-by-jowl with businesses i.e. in the same apartment complex. Hence the push ( I think) for Class B everything for ITE. There is also this presumption of quality. A Class B piece of gear has lower emissions. Therefore the quality must be higher. Having said all that - this thrust MUST be resisted stoutly at all levels for any number of reasons: 1) Cost - We have already invested dollars in immunity. 2) Need - There is no data to support the assumption that Class A gear has/will cause widespread disaster. 3) Legislated Quality. - Need I say more. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: EN55024
Richard, I agree! But why define a product standard (EN55024 in particular) that defines limits that are only appropriate for a residential, commercial and light industrial environment. Am I missing something? Thanks in advance, William D'Orazio CAE Electronics Ltd. Electrical System Designer Phone: (514) 341-2000 (X4555) Fax: (514)340-5552 Email: dora...@cae.ca -Original Message- From: wo...@sensormatic.com [mailto:wo...@sensormatic.com] Sent: Wednesday, December 06, 2000 2:28 PM To: emc-p...@majordomo.ieee.org Subject: RE: EN55024 The answer to this debate is included in the essential requirement that a product not cause undue interference and that it operate as intended in its intended environment. The key is the intended environment. Class A equipment installed in a residential environment would not comply with the essential requirements. However, that same equipment would comply if installed all other types of environments. The standard is clear that the manufacturer must warn the user that the equipment is a Class A device. At that point it is the responsibility of the user to ensure that the equipment is not used in a residential environment. Richard Woods -- From: Pettit, Ghery [SMTP:ghery.pet...@intel.com] Sent: Wednesday, December 06, 2000 1:57 PM To: 'cet...@cetest.nl'; Pettit, Ghery; 'William D'Orazio'; EMC Posting (E-mail) Subject: RE: EN55024 Let's discuss apples vs apples and keep the discussion to ITE. Household appliances are not subject to EN 55022:1998, but have their own product specific standard. The law is 89/336/EEC, the EMC Directive (or as I like to call it, the EMC Professional Employment Act of 1989). It lays down, as you note, the essential requirement that a product not cause undue interference and that it operate as intended in its itended environment. No more, no less. No limits for emissions are provided in the EMC Directive. The question then comes up, how do we show compliance with the essential requirements in 89/336/EEC? The answer, of course, is to test to the applicable requirements that have been published in the OJ. For ITE, the emissions limits are contained in EN 55022:1998. Fine. I read EN 55022:1998 and it is simply a number of modifications to CISPR 22, 3rd Edition. Well and good. I read CISPR 22, 3rd Edition and it defines Class A and Class B. If there are different emissions limits between various standards, that needs to be addressed in CISPR. My question is this - is there a significant interference problem in Europe from ITE? Based on a survey returned by over 50,000 households in the U.S., there certainly isn't one here. Whatever is being done, it is adequate. Peace! Ghery -Original Message- From: CE-test - Ing. Gert Gremmen - ce-marking and more... [mailto:cet...@cetest.nl] Sent: Wednesday, December 06, 2000 10:39 AM To: Pettit, Ghery; 'William D'Orazio'; EMC Posting (E-mail) Subject: RE: EN55024 Hi Ghery,group, Standards are NO LAW ! My reply was directed against the Clause in EN 55022, not against the possibility of EN 55022 to define suitable environments. However, there is a standards writing committee guidance document that requests the committees not to deviate more then absolutely needed from the test levels and environmental conditions as described in the generic standards EN 50082-1/2. The standards writing committees have been very independent (members of CENELEC) and all kind of powers could and have been influencing the contents of many standards. Even today commercial interests find their way into harmonized standards. The EC requested CENELEC to create standards that are compatible to the Essential requirements of the EMC-directive, it cannot be so that a house hold kitchen machine need to comply to other limits then a house hold computer. The interference a receiver receives is not less interfering if it comes from a vacuum cleaner or from a modem. Same environment, same levels. The problem comes with mixed environment products. In the past products could escape from limits by a warning label "this product may cause radio interference" and the suggestion to increase distance between products. At low reception levels of FM-radio and the close distances of modern urban livings that solution is not sufficient anymore. Product group level EN-type harmonized standards are (in Europe) targeted towards the details of "how to test" and "how to judge performance" and "how to connect test gear" and only deviate from levels and frequency range in the benefit of the product group if absolutely necessary. It would be absolutely unjust if some equipment would be able to interfere more then others, just because it had a label on it saying that it would only be allowed to use it in an heavy industrial environment, if the equipment (such as a mainframe) itself suggests their application in a domestic or mixed environment. Manufacturers of Class B complying equipment could easily sue man
Current revision of the aircraft Standard (RTCA-D0-160?)?
Gents, I have a couple of questions concerning equipment onboard aircrafts: I was just wondering if the current revision of RTCA-DO-160 is D. Is it possible that manufacturers are still using B. As I do not have the B revision of the standard, does the B revision have a clause that addresses Immunity to Electrostatic Discharge? If so may someone provide me with the required test level? In addition the D revision doesn't define a test setup, is anyone aware of the test setup used by the manufacturers. Any comments will be greatly appreciated. Thanks in advance, <<...>> William D'Orazio CAE Electronics Ltd. Electrical System Designer Phone: (514) 341-2000 (X4555) Fax: (514)340-5552 Email: dora...@cae.ca --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Re: EN55024
Hi Ghery. You wrote: << The law is 89/336/EEC, the EMC Directive (or as I like to call it, the EMC Professional Employment Act of 1989). It lays down, as you note, the essential requirement that a product not cause undue interference and that it operate as intended in its itended environment. No more, no less. No limits for emissions are provided in the EMC Directive. >> The Euro Directive was born of the Treat of Rome, itself born in 1972, with the express purpose of removing barriers to trade. If you read the Directive, in the first few pages I think (from memory) that it mentions 'Free trade', 'removal of barriers to trade', 'etc. etc about ten times, but in just about the whole of the document it doesn't mention Interference or crackling radios at all. The Directive is there to ensure that no Euro state can steal a lead on another by selling goods that don't have the same technical performance, i.e. that are cheaper! By doing what the Directive requires, and applying the CE mark, it simply allows the bureacrats to let the goods in without let or hindrance so that they can be traded on an equal footing with locally produced goods. Trade = peace, which isn't a bad thing... I suspect that the Euro MP's wouldn't know an EMC if it fell on their foot, but they voted it in, as it was something that could be measured and defined relatively easily and could therefore be given political force. The technical standards, CISPR etc. seem to be quite arbitary in places. For instance, the sudden cessation of conducted emissions and the equally sudden beginning or radiated emissions at 30MHz is surely a bit convenient, tho' it has to be said it is not entirely impractical. No, I reckon that the EMC Directive is not anything to do with EMC, but another tool by which the Euro Bureacrats can merge Europe into this Super State so feared by the Brits and so revered by the Galls. There, a bit of unsolicited trite bigotry, and it isn't even Friday. Chris Dupres Surrey, UK. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Re:Insulation failure - recent data
If anyone is working on such a paper, please consider presenting it at the TC-8 session of either the 2001 or 2002 IEEE EMC Symposium. Jim (Yes I am a little behind in reading the postings). Reply Separator Subject:Insulation failure - recent data Author: "Pete Perkins" List-Post: emc-pstc@listserv.ieee.org Date: 11/12/00 11:46 PM PSNet We don't seem to get published data based upon testing to the standards with which we normally work. Dr Pfeiffer (whom we know from the 28A/664 work) and his colleagues have performed an evaluation of the failures of equipment to impulses as defined in 61000-4-5, which are in agreement with the principles of insulation coordination. Failures of electronic equipment caused by transient overvoltages are increasing rapidly is a part of the header for this paper. The particulars are contained in the article, but the thrust of the evaluation is that the equipment failed what is considered to be a reasonable test. 13 of 20 power supplies failed the test. Although this is described as an EMC test, it certainly has safety implications. The abrogation of protective insulation can lead to fire or electric shock from the failure. The article suggests the addition of a series impedance as a step in protection until the insulation in the capacitors is improved. The article is from the IEEE Electrical Insulation Magazine, March/April 2000 - Vol 16, No 2. Get your librarian to chase it down for you... It would be nice to get more published data on this... anyone putting together a paper??? br, Pete Peter E Perkins, PE Principal Product Safety Consultant Tigard, ORe 97281-3427 503/452-1201 fone/fax p.perk...@ieee.org --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org Received: from ruebert.ieee.org ([199.172.136.3]) by mail.monarch.com with SMTP (IMA Internet Exchange 3.14) id 2C1E; Mon, 13 Nov 2000 04:46:39 -0800 Received: by ruebert.ieee.org (8.9.3/8.9.3)id CAA09446; Mon, 13 Nov 2000 02:47:51 -0500 (EST) From: "Pete Perkins" To: "PSNet" Subject: Insulation failure - recent data List-Post: emc-pstc@listserv.ieee.org Date: Sun, 12 Nov 2000 23:46:22 -0800 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; Content-Transfer-Encoding: 7bit X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook IMO, Build 9.0.2416 (9.0.2911.0) Importance: Normal X-MimeOLE: Produced By Microsoft MimeOLE V5.50.4133.2400 X-Apparently-From: peperkin...@cs.com Sender: owner-emc-p...@ieee.org Precedence: bulk Reply-To: "Pete Perkins" X-Resent-To: Multiple Recipients X-Listname: emc-pstc X-Info: Help requests to emc-pstc-requ...@majordomo.ieee.org X-Info: [Un]Subscribe requests to majord...@majordomo.ieee.org X-Moderator-Address: emc-pstc-appro...@majordomo.ieee.org --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: EN55024
Whoa! I work in CISPR 11 land, but as I recall, CISPR 22 works almost identically in this regard. The difference between CISPR 11 and 22 is what TYPE of equipment it is. CISPR 11 covers Industrial, scientific and medical (ISM) equipment. CISPR 11 covers Information technology equipment (ITE). BOTH standards contain classification instructions for Class A and Class B. To paraphrase CISPR 11, Class A equipment is equipment suitable for use in all establishments other than domestic and Class B equipment is equipment suitable for use in domestic establishments. So, ITE equipment may certainly be classified either A or B. The trick is that a lot of ITE is now being used in "domestic establishments." I think what Gert was saying is that you can't sell something that has domestic users as logical buyers (like a PC), but sell it as Class A with a warning label about domestic use. THAT doesn't wash. Paul O'Shaughnessy Affymetrix, Inc. -Original Message- From: Pettit, Ghery [mailto:ghery.pet...@intel.com] Sent: Wednesday, December 06, 2000 11:25 AM To: 'CE-test - Ing. Gert Gremmen - ce-marking and more...'; Pettit, Ghery; 'William D'Orazio'; EMC Posting (E-mail) Subject: RE: EN55024 Gert, All ITE equipment must meet the Class B limits? Where does it say that in either EN 55022:1998 or CISPR 22, 3rd Edition? Section 4.1 of CISPR 22 is quite clear about what equipment must meet the Class B limits. There are many types of ITE that do not fall into the examples provided in the document. EN 55022 does not amend this part of the document in its common modifications. As 89/336/EEC does not provide limits of any kind, where am I supposed to see a requirement that servers and mainframe computers (which are, indeed, ITE) must meet the Class B limits? Ghery Pettit -Original Message- From: CE-test - Ing. Gert Gremmen - ce-marking and more... [mailto:cet...@cetest.nl] Sent: Wednesday, December 06, 2000 1:14 AM To: Pettit, Ghery; 'William D'Orazio'; EMC Posting (E-mail) Subject: RE: EN55024 Hi Group, The type of clause (see below) from EN 55022 about adding notes and restrictions to equipment is just the type the European Commission objects against their use in the EN 55022 standard. The reason is that the CENELEC was asked to propose limits and test methods, not to replace politics by limitng the applicability of their standards. The use of such a clause to sell ITE equipment to Class A limits is illegal and will not hold when the presumption of conformity to the essential requirements of the EMC-directive is being tested. Information equipment is and wil be used in all environments, therefore the distinction between such environments is artificial. Regards, Gert Gremmen, (Ing) ce-test, qualified testing === Web presence http://www.cetest.nl CE-shop http://www.cetest.nl/ce_shop.htm /-/ Compliance testing is our core business /-/ === >>-Original Message- >>From: owner-emc-p...@ieee.org [mailto:owner-emc-p...@ieee.org]On Behalf >>Of Pettit, Ghery >>Sent: Tuesday, December 05, 2000 11:46 PM >>To: 'William D'Orazio'; Pettit, Ghery; EMC Posting (E-mail) >>Subject: RE: EN55024 >> >> >> >>OK. EN 55022 is the ITE specific emissions standard. It does >>have two sets >>of limits with a statement that Class B is intended for certain product >>types which may be used in a domestic type environment and a >>statement that >>Class A products should have a warning that they may cause interference if >>used in a domestic environment. CISPR 22 does not use the term >>"industrial" >>to define an environment. It merely warns that the class A limits may not >>provide enough protection to neighboring users of the RF spectrum if the >>device is used in a domestic environment. >> >>Ghery >> >>-Original Message- >>From: William D'Orazio [mailto:dora...@cae.ca] >>Sent: Tuesday, December 05, 2000 2:37 PM >>To: 'Pettit, Ghery'; William D'Orazio; EMC Posting (E-mail) >>Subject: RE: EN55024 >> >> >>BYI, EN55011 should read EN55022. >> >>William D'Orazio >>CAE Electronics Ltd. >>Electrical System Designer >> >>Phone: (514) 341-2000 (X4555) >>Fax: (514)340-5552 >>Email: dora...@cae.ca >> >> >>-Original Message- >>From: Pettit, Ghery [mailto:ghery.pet...@intel.com] >>Sent: Tuesday, December 05, 2000 5:33 PM >>To: 'William D'Orazio'; EMC Posting (E-mail) >>Subject: RE: EN55024 >> >> >>EN 55024 is the ITE specific immunity standard. It is based on CISPR 24 >>which makes no distinction between environments. EN 55011 is >>based on CISPR >>11 and relates to different product families. They do not come from the >>same subcommittees in CISPR, so it's like comparing apples and oranges. >> >>Ghery Pettit >>Intel >> >>-Original Message- >>From: William D'Orazio [mailto:dora...@cae.ca] >>Sent: Tuesday, December 05, 2000 1:22 PM >>To: EMC Posting (E-mail) >>Subject: EN55024 >> >> >> >>Gents, >
FCC Part 18: Conducted emissions frequency range versus LISN performance
I'll be testing a product to FCC Part 18 for the first time, and I'm trying to familiarize myself with the limits in this requirement. In section 18.307(a), conducted emissions limits are specified for ultrasonic equipment. They start at 10kHz, and stop at 30MHz. Yet the measurement procedure specified in section 18.311 (MP-5) gives a graph of LISN performance that only goes down to 150kHz. Am I missing something, or is this the way the regulations read? Patrick Lawler plaw...@west.net --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: EN55024
The answer to this debate is included in the essential requirement that a product not cause undue interference and that it operate as intended in its intended environment. The key is the intended environment. Class A equipment installed in a residential environment would not comply with the essential requirements. However, that same equipment would comply if installed all other types of environments. The standard is clear that the manufacturer must warn the user that the equipment is a Class A device. At that point it is the responsibility of the user to ensure that the equipment is not used in a residential environment. Richard Woods -- From: Pettit, Ghery [SMTP:ghery.pet...@intel.com] Sent: Wednesday, December 06, 2000 1:57 PM To: 'cet...@cetest.nl'; Pettit, Ghery; 'William D'Orazio'; EMC Posting (E-mail) Subject: RE: EN55024 Let's discuss apples vs apples and keep the discussion to ITE. Household appliances are not subject to EN 55022:1998, but have their own product specific standard. The law is 89/336/EEC, the EMC Directive (or as I like to call it, the EMC Professional Employment Act of 1989). It lays down, as you note, the essential requirement that a product not cause undue interference and that it operate as intended in its itended environment. No more, no less. No limits for emissions are provided in the EMC Directive. The question then comes up, how do we show compliance with the essential requirements in 89/336/EEC? The answer, of course, is to test to the applicable requirements that have been published in the OJ. For ITE, the emissions limits are contained in EN 55022:1998. Fine. I read EN 55022:1998 and it is simply a number of modifications to CISPR 22, 3rd Edition. Well and good. I read CISPR 22, 3rd Edition and it defines Class A and Class B. If there are different emissions limits between various standards, that needs to be addressed in CISPR. My question is this - is there a significant interference problem in Europe from ITE? Based on a survey returned by over 50,000 households in the U.S., there certainly isn't one here. Whatever is being done, it is adequate. Peace! Ghery -Original Message- From: CE-test - Ing. Gert Gremmen - ce-marking and more... [mailto:cet...@cetest.nl] Sent: Wednesday, December 06, 2000 10:39 AM To: Pettit, Ghery; 'William D'Orazio'; EMC Posting (E-mail) Subject: RE: EN55024 Hi Ghery,group, Standards are NO LAW ! My reply was directed against the Clause in EN 55022, not against the possibility of EN 55022 to define suitable environments. However, there is a standards writing committee guidance document that requests the committees not to deviate more then absolutely needed from the test levels and environmental conditions as described in the generic standards EN 50082-1/2. The standards writing committees have been very independent (members of CENELEC) and all kind of powers could and have been influencing the contents of many standards. Even today commercial interests find their way into harmonized standards. The EC requested CENELEC to create standards that are compatible to the Essential requirements of the EMC-directive, it cannot be so that a house hold kitchen machine need to comply to other limits then a house hold computer. The interference a receiver receives is not less interfering if it comes from a vacuum cleaner or from a modem. Same environment, same levels. The problem comes with mixed environment products. In the past products could escape from limits by a warning label "this product may cause radio interference" and the suggestion to increase distance between products. At low reception levels of FM-radio and the close distances of modern urban livings that solution is not sufficient anymore. Product group level EN-type harmonized standards are (in Europe) targeted towards the details of "how to test" and "how to judge performance" and "how to connect test gear" and only deviate from levels and frequency range in the benefit of the product group if absolutely necessary. It would be absolutely unjust if some equipment would be able to interfere more then others, just because it had a label on it saying that it would only be allowed to use it in an heavy industrial environment, if the equipment (such as a mainframe) itself suggests their application in a domestic or mixed environment. Manufacturers of Class B complying equipment could easily sue manufacturers of equivalent Class A equipment if their limit exceeding interference was not due to absolutely \ necessary requirements given by the nature of the product or process being done. (Fa electro-heating with RF-waves, welding and therapeutic use of RF-frequencies) Please Note also that the report mentioned is for the standards writing committees of CENELEC creating harmonized standards and is not applicable for IEC and/or CISPR versions of the same standard. Hope to got things straightened out somewhat. Regards, Gert Gremmen, (Ing) ce-test, q
RE: EN55024
Let's discuss apples vs apples and keep the discussion to ITE. Household appliances are not subject to EN 55022:1998, but have their own product specific standard. The law is 89/336/EEC, the EMC Directive (or as I like to call it, the EMC Professional Employment Act of 1989). It lays down, as you note, the essential requirement that a product not cause undue interference and that it operate as intended in its itended environment. No more, no less. No limits for emissions are provided in the EMC Directive. The question then comes up, how do we show compliance with the essential requirements in 89/336/EEC? The answer, of course, is to test to the applicable requirements that have been published in the OJ. For ITE, the emissions limits are contained in EN 55022:1998. Fine. I read EN 55022:1998 and it is simply a number of modifications to CISPR 22, 3rd Edition. Well and good. I read CISPR 22, 3rd Edition and it defines Class A and Class B. If there are different emissions limits between various standards, that needs to be addressed in CISPR. My question is this - is there a significant interference problem in Europe from ITE? Based on a survey returned by over 50,000 households in the U.S., there certainly isn't one here. Whatever is being done, it is adequate. Peace! Ghery -Original Message- From: CE-test - Ing. Gert Gremmen - ce-marking and more... [mailto:cet...@cetest.nl] Sent: Wednesday, December 06, 2000 10:39 AM To: Pettit, Ghery; 'William D'Orazio'; EMC Posting (E-mail) Subject: RE: EN55024 Hi Ghery,group, Standards are NO LAW ! My reply was directed against the Clause in EN 55022, not against the possibility of EN 55022 to define suitable environments. However, there is a standards writing committee guidance document that requests the committees not to deviate more then absolutely needed from the test levels and environmental conditions as described in the generic standards EN 50082-1/2. The standards writing committees have been very independent (members of CENELEC) and all kind of powers could and have been influencing the contents of many standards. Even today commercial interests find their way into harmonized standards. The EC requested CENELEC to create standards that are compatible to the Essential requirements of the EMC-directive, it cannot be so that a house hold kitchen machine need to comply to other limits then a house hold computer. The interference a receiver receives is not less interfering if it comes from a vacuum cleaner or from a modem. Same environment, same levels. The problem comes with mixed environment products. In the past products could escape from limits by a warning label "this product may cause radio interference" and the suggestion to increase distance between products. At low reception levels of FM-radio and the close distances of modern urban livings that solution is not sufficient anymore. Product group level EN-type harmonized standards are (in Europe) targeted towards the details of "how to test" and "how to judge performance" and "how to connect test gear" and only deviate from levels and frequency range in the benefit of the product group if absolutely necessary. It would be absolutely unjust if some equipment would be able to interfere more then others, just because it had a label on it saying that it would only be allowed to use it in an heavy industrial environment, if the equipment (such as a mainframe) itself suggests their application in a domestic or mixed environment. Manufacturers of Class B complying equipment could easily sue manufacturers of equivalent Class A equipment if their limit exceeding interference was not due to absolutely \ necessary requirements given by the nature of the product or process being done. (Fa electro-heating with RF-waves, welding and therapeutic use of RF-frequencies) Please Note also that the report mentioned is for the standards writing committees of CENELEC creating harmonized standards and is not applicable for IEC and/or CISPR versions of the same standard. Hope to got things straightened out somewhat. Regards, Gert Gremmen, (Ing) ce-test, qualified testing === Web presence http://www.cetest.nl CE-shop http://www.cetest.nl/ce_shop.htm /-/ Compliance testing is our core business /-/ === >>-Original Message- >>From: Pettit, Ghery [mailto:ghery.pet...@intel.com] >>Sent: Wednesday, December 06, 2000 5:25 PM >>To: 'CE-test - Ing. Gert Gremmen - ce-marking and more...'; Pettit, >>Ghery; 'William D'Orazio'; EMC Posting (E-mail) >>Subject: RE: EN55024 >> >> >>Gert, >> >>All ITE equipment must meet the Class B limits? Where does it say that in >>either EN 55022:1998 or CISPR 22, 3rd Edition? Section 4.1 of CISPR 22 is >>quite clear about what equipment must meet the Class B limits. There are >>many types of ITE that do not fall into the examples provided in the >>document. EN 55022 does
RE: EN55024
Hi Ghery,group, Standards are NO LAW ! My reply was directed against the Clause in EN 55022, not against the possibility of EN 55022 to define suitable environments. However, there is a standards writing committee guidance document that requests the committees not to deviate more then absolutely needed from the test levels and environmental conditions as described in the generic standards EN 50082-1/2. The standards writing committees have been very independent (members of CENELEC) and all kind of powers could and have been influencing the contents of many standards. Even today commercial interests find their way into harmonized standards. The EC requested CENELEC to create standards that are compatible to the Essential requirements of the EMC-directive, it cannot be so that a house hold kitchen machine need to comply to other limits then a house hold computer. The interference a receiver receives is not less interfering if it comes from a vacuum cleaner or from a modem. Same environment, same levels. The problem comes with mixed environment products. In the past products could escape from limits by a warning label "this product may cause radio interference" and the suggestion to increase distance between products. At low reception levels of FM-radio and the close distances of modern urban livings that solution is not sufficient anymore. Product group level EN-type harmonized standards are (in Europe) targeted towards the details of "how to test" and "how to judge performance" and "how to connect test gear" and only deviate from levels and frequency range in the benefit of the product group if absolutely necessary. It would be absolutely unjust if some equipment would be able to interfere more then others, just because it had a label on it saying that it would only be allowed to use it in an heavy industrial environment, if the equipment (such as a mainframe) itself suggests their application in a domestic or mixed environment. Manufacturers of Class B complying equipment could easily sue manufacturers of equivalent Class A equipment if their limit exceeding interference was not due to absolutely \ necessary requirements given by the nature of the product or process being done. (Fa electro-heating with RF-waves, welding and therapeutic use of RF-frequencies) Please Note also that the report mentioned is for the standards writing committees of CENELEC creating harmonized standards and is not applicable for IEC and/or CISPR versions of the same standard. Hope to got things straightened out somewhat. Regards, Gert Gremmen, (Ing) ce-test, qualified testing === Web presence http://www.cetest.nl CE-shop http://www.cetest.nl/ce_shop.htm /-/ Compliance testing is our core business /-/ === >>-Original Message- >>From: Pettit, Ghery [mailto:ghery.pet...@intel.com] >>Sent: Wednesday, December 06, 2000 5:25 PM >>To: 'CE-test - Ing. Gert Gremmen - ce-marking and more...'; Pettit, >>Ghery; 'William D'Orazio'; EMC Posting (E-mail) >>Subject: RE: EN55024 >> >> >>Gert, >> >>All ITE equipment must meet the Class B limits? Where does it say that in >>either EN 55022:1998 or CISPR 22, 3rd Edition? Section 4.1 of CISPR 22 is >>quite clear about what equipment must meet the Class B limits. There are >>many types of ITE that do not fall into the examples provided in the >>document. EN 55022 does not amend this part of the document in its common >>modifications. As 89/336/EEC does not provide limits of any >>kind, where am >>I supposed to see a requirement that servers and mainframe >>computers (which >>are, indeed, ITE) must meet the Class B limits? >> >>Ghery Pettit >> >>-Original Message- >>From: CE-test - Ing. Gert Gremmen - ce-marking and more... >>[mailto:cet...@cetest.nl] >>Sent: Wednesday, December 06, 2000 1:14 AM >>To: Pettit, Ghery; 'William D'Orazio'; EMC Posting (E-mail) >>Subject: RE: EN55024 >> >> >>Hi Group, >> >>The type of clause (see below) from EN 55022 about adding notes and >>restrictions >>to equipment is just the type the European Commission >>objects against their use in the EN 55022 standard. >> >>The reason is that the CENELEC was asked to propose limits and >>test methods, not to replace politics by limitng the applicability >>of their standards. >> >>The use of such a clause to sell ITE equipment to Class A limits >>is illegal >>and will not hold when the presumption of conformity to the essential >>requirements >>of the EMC-directive is being tested. >> >>Information equipment is and wil be used in all environments, therefore >>the distinction between such environments is artificial. >> >> >> >>Regards, >> >>Gert Gremmen, (Ing) >> >>ce-test, qualified testing >> >>=== >>Web presence http://www.cetest.nl >>CE-shop http://www.cetest.nl/ce_shop.htm >>/-/ Compliance testing is our core business /-/ >>===
Re:Grounding
I agree that grounding is a complex topic which can't be fully covered within this forum. However, I must make a general comment with regard to single point ground versus multi-point ground for a digital board. There is in fact no such thing as a single point ground for a digital board because of distributed capacitive coupling between the digital board and the system reference plane. If a single-point ground is attempted, you end up instead with large RF current return loop areas which become antennas for radiation and susceptibility. To minimize the loops, you must "short out" the capacitive coupling by connecting the digital circuit ground plane in the board directly to the reference plane of your system at multi-points. Each connection creates its own little "loop" between the circuit ground plane and reference plane, but these loops are smaller and more controlled than the loops that are formed with the distributed capacitive coupling. Methods of multi-point grounding and other details of circuit board design can be found in a number of publications. I recommend "Printed Circuit Board Design Techniques for EMC Complance" by Mark Montrose or "Noise Reduction Techniques in Electronic Systems" by Henry Ott. Jim Hulbert Senior Engineer - EMC Pitney Bowes brian_kunde on 12/06/2000 11:36:04 AM Please respond to brian_kunde To: PRao , emc-pstc cc:(bcc: Jim Hulbert/MSD/US/PBI) Subject: Re:Grounding Hello Praveen, The topic in which your question addresses is "Grounding". Grounding is one of the most complex topics EMC engineers have to deal with especially in a design that has both Analog and Digital circuitry. Most every case is different and there are thousands of variables to consider. I will address the most basic points and hope they will help you out. The concept of Ground Loops or Earth Loops is more of an analog issue than digital. Lower frequency and usually low voltage analog signals can be very sensitive to Ground Loops. On the other hand, digital circuitry is less effected by ground loops and in most cases it is desired to keep the loop areas as short as possible. This is usually accomplished by grounding digital circuitry as often as possible. Bypass caps and other de-coupling components are also reducing loop area. It is still a debatable topic on whether Digital PC cards should have a single point ground or multipoint. I think in most cases it just depends on the application. But, I think most everyone will agree that getting a good ground connection on both ends of a digital I/O cable is a must. You also need to have a good PE ground connection between equipment and its peripherals or it will have trouble passing the immunity tests you listed below (not to mention possible radiated emissions problems). My advice it this internal to your design you should do a good job of isolating Digital and Analog circuitry to keep digital noise out of your analog. Digital I/O should be grounded well at BOTH ends of the cable providing a good return path for signals and providing a common Earth Reference to between the main unit and the peripherals. Like I said, these are only the basic concepts that apply most of the time. Good luck, Brian Reply Separator Subject:Grounding Author: Praveen Rao List-Post: emc-pstc@listserv.ieee.org Date: 12/6/00 6:52 PM Hello Group, We currently have a system which has modules in a box(metal) with floating digital and analog grounds.It is a Class 1 (safety) equipment. We intend to connect the 0V of each board to protective earth (chassis) at a common single point at the power supply. By doing this, the conducted emissions, ESD, Surges, etc show better results. We have a serial port (DB9)on the device which is only used for configuring Our concern is when a PC is connected to this port, cause in PCs the signal ground (pin 5) is normally connected to PE. So, when a PC is connected to the serial port of our system we may end up with signal grounds on each end of this serial cable connected to it's own device PE. This may cause earth loops. Since this is only a config port, approvals may not be an issue but functionally in the field this may create problems. Is it common to connect digital grounds to a single point chassi ground directly at the power supply ? Should there be any concern from functionality point of view ? especially when a PC is connected to our serial port. Your comments will be greatly appreciated. Praveen Rao --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy quest
IEEE Standards for IEE Members
Nick, I have confirmed that there currently is not a reciprocal agreement for discounting of the price of the standard for our IEE colleagues. I will note that the member discount is $17 for the print version and $26 for the electronic version, which would likely pay for 20-30% of an IEEE membership. Regards, Michael Garretson 2000/2001 Chairman, IEEE Membership Development Committee Nick Williams cc: Sent by: Subject: IEEE Standards owner-emc-p...@ieee.org 12/06/2000 01:23 AM Please respond to Nick Williams I'm wanting to obtain a copy of IEE STD 739-1995 which I know can be downloaded from the IEEE web site. However, I was wondering if, as a member of the British IEE, there is any kind of reciprocal agreement where I can obtain IEEE documents at the IEEE member price. Does anyone know anything about this? All help gratefully received. Nick. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: Calibration labs
All, If you worry like I do about equipment loss, damage and other Murphy type effects, ask your local cal lab if they will do on-site calibrations. We had our Haefely Trench burst and surge testers calibrated recently on-site by PCI here in Austin, Texas. The cost was very reasonable, plus it gave us the opportunity to witness the process and help the technician operate the equipment, saving him some time. I like the fact that the equipment stays in the lab and avoids the stresses and risks of shipment. Best Regards, Eric Lifsey -- Compliance Manager -- National Instruments -- USA 512-683-8474 -- Fax 512-683-8880 UMBDENSTOCK@senso rmatic.com To: emc-p...@majordomo.ieee.org, Sent by: ken.ja...@emccompliance.com owner-emc-pstc@iecc: ee.org Subject: RE: Calibration labs 12/06/2000 07:49 AM Please respond to UMBDENSTOCK We schedule in advance and usually get 1 week turnaround on cal plus shipping time. We specify 2nd day Fedex. This makes the disruption to our lab scheduling a minimum. Winter can pose some unexpected delays due to weather conditions on the open area test site. Plan your cals for summer when possible. Liberty Labs cal our antennas, LISNs, CDNs, surge generator, ESD simulator, EFT generator. Agilent does our spectrum analyzers. The key to minimum down time is arrangements in advance. > -- > From: Ken Javor[SMTP:ken.ja...@emccompliance.com] > Reply To:Ken Javor > Sent: Tuesday, December 05, 2000 5:53 PM > To: Ray Levasseur; wo...@sensormatic.com; emc-p...@majordomo.ieee.org > Subject: Re: Calibration labs > > > What kind of turn-around times are typical of cal labs? Not just for > antennas but also for items such as spectrum analyzers? Thank you. > > -- > >From: "Ray Levasseur" > >To: wo...@sensormatic.com, emc-p...@majordomo.ieee.org > >Subject: RE: Calibration labs > >Date: Tue, Dec 5, 2000, 3:14 PM > > > > > > > Our company is located in BC on the west coast of Canada and we use > Liberty > > Labs and are very happy with the service and quality. The turnaround > time is > > very reasonable. > > > > Ray Levasseur > > EMC Compliance > > CreoScitex > > > > > >>From: wo...@sensormatic.com > >>Reply-To: wo...@sensormatic.com > >>To: emc-p...@majordomo.ieee.org > >>Subject: RE: Calibration labs > >>Date: Tue, 5 Dec 2000 14:49:40 -0500 > >> > >> > >>Our EMC equipment is calibrated by Liberty Labs (not in California) and > we > >>have been very happy with their pricing and service. > >> > >>Richard Woods > >> > >>-- > >>From: Brian Tan [SMTP:briant20002...@yahoo.com] > >>Sent: Tuesday, December 05, 2000 2:12 PM > >>To: emc-p...@majordomo.ieee.org > >>Subject: Calibration labs > >> > >> > >>Hello; > >>I am looking for a good calibration laboratory to > >>perform the yearly calibration for our instruments. > >>Can anyone tell me which one has good reputation in > >>the California? Right now, we use a lab called > >>Precision Measurement in Northern California and that > >>lab doesn't do a good job. Thanks in advance. > >> > >>Brian > >> > >>__ > >> > > > > > __ > __ > _ > > > > Get more from the Web. FREE MSN Explorer download : > http://explorer.msn.com > > > > > > --- > > This message is from the IEEE EMC Society Product Safety > > Technical Committee emc-pstc discussion list. > > > > 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: > > Jim Bacher: jim_bac...@mail.monarch.com > > Michael Garretson:pstc_ad...@garretson.org > > > > For p
RE: EN55024
Gert, All ITE equipment must meet the Class B limits? Where does it say that in either EN 55022:1998 or CISPR 22, 3rd Edition? Section 4.1 of CISPR 22 is quite clear about what equipment must meet the Class B limits. There are many types of ITE that do not fall into the examples provided in the document. EN 55022 does not amend this part of the document in its common modifications. As 89/336/EEC does not provide limits of any kind, where am I supposed to see a requirement that servers and mainframe computers (which are, indeed, ITE) must meet the Class B limits? Ghery Pettit -Original Message- From: CE-test - Ing. Gert Gremmen - ce-marking and more... [mailto:cet...@cetest.nl] Sent: Wednesday, December 06, 2000 1:14 AM To: Pettit, Ghery; 'William D'Orazio'; EMC Posting (E-mail) Subject: RE: EN55024 Hi Group, The type of clause (see below) from EN 55022 about adding notes and restrictions to equipment is just the type the European Commission objects against their use in the EN 55022 standard. The reason is that the CENELEC was asked to propose limits and test methods, not to replace politics by limitng the applicability of their standards. The use of such a clause to sell ITE equipment to Class A limits is illegal and will not hold when the presumption of conformity to the essential requirements of the EMC-directive is being tested. Information equipment is and wil be used in all environments, therefore the distinction between such environments is artificial. Regards, Gert Gremmen, (Ing) ce-test, qualified testing === Web presence http://www.cetest.nl CE-shop http://www.cetest.nl/ce_shop.htm /-/ Compliance testing is our core business /-/ === >>-Original Message- >>From: owner-emc-p...@ieee.org [mailto:owner-emc-p...@ieee.org]On Behalf >>Of Pettit, Ghery >>Sent: Tuesday, December 05, 2000 11:46 PM >>To: 'William D'Orazio'; Pettit, Ghery; EMC Posting (E-mail) >>Subject: RE: EN55024 >> >> >> >>OK. EN 55022 is the ITE specific emissions standard. It does >>have two sets >>of limits with a statement that Class B is intended for certain product >>types which may be used in a domestic type environment and a >>statement that >>Class A products should have a warning that they may cause interference if >>used in a domestic environment. CISPR 22 does not use the term >>"industrial" >>to define an environment. It merely warns that the class A limits may not >>provide enough protection to neighboring users of the RF spectrum if the >>device is used in a domestic environment. >> >>Ghery >> >>-Original Message- >>From: William D'Orazio [mailto:dora...@cae.ca] >>Sent: Tuesday, December 05, 2000 2:37 PM >>To: 'Pettit, Ghery'; William D'Orazio; EMC Posting (E-mail) >>Subject: RE: EN55024 >> >> >>BYI, EN55011 should read EN55022. >> >>William D'Orazio >>CAE Electronics Ltd. >>Electrical System Designer >> >>Phone: (514) 341-2000 (X4555) >>Fax: (514)340-5552 >>Email: dora...@cae.ca >> >> >>-Original Message- >>From: Pettit, Ghery [mailto:ghery.pet...@intel.com] >>Sent: Tuesday, December 05, 2000 5:33 PM >>To: 'William D'Orazio'; EMC Posting (E-mail) >>Subject: RE: EN55024 >> >> >>EN 55024 is the ITE specific immunity standard. It is based on CISPR 24 >>which makes no distinction between environments. EN 55011 is >>based on CISPR >>11 and relates to different product families. They do not come from the >>same subcommittees in CISPR, so it's like comparing apples and oranges. >> >>Ghery Pettit >>Intel >> >>-Original Message- >>From: William D'Orazio [mailto:dora...@cae.ca] >>Sent: Tuesday, December 05, 2000 1:22 PM >>To: EMC Posting (E-mail) >>Subject: EN55024 >> >> >> >>Gents, >> >> Why is it that EN55011 defines test levels for both industrial and >>residential environments (class A, B) and EN55024 does not? Are >>the levels >>in EN55024 applicable to all environments (obviously not) so how does one >>define the test levels for an ITE in an industrial environment? >> >>Thanks in advance, >> >> <<...>> >> >>William D'Orazio >>CAE Electronics Ltd. >>Electrical System Designer >> >>Phone: (514) 341-2000 (X4555) >>Fax: (514)340-5552 >>Email: dora...@cae.ca >> >> >>--- >>This message is from the IEEE EMC Society Product Safety >>Technical Committee emc-pstc discussion list. >> >>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: >> Jim Bacher: jim_bac...@mail.monarch.com >> Michael Garretson:pstc_ad...@garretson.org >> >>For policy questions, send mail to: >> Richard Nute: ri...@ieee.org >> >> >> >> >>--- >>This message is from the IEEE EMC Society Product Safety >>Technical Committee emc-pstc discussion list. >> >>To cancel yo
Re:Grounding
Hello Praveen, The topic in which your question addresses is "Grounding". Grounding is one of the most complex topics EMC engineers have to deal with especially in a design that has both Analog and Digital circuitry. Most every case is different and there are thousands of variables to consider. I will address the most basic points and hope they will help you out. The concept of Ground Loops or Earth Loops is more of an analog issue than digital. Lower frequency and usually low voltage analog signals can be very sensitive to Ground Loops. On the other hand, digital circuitry is less effected by ground loops and in most cases it is desired to keep the loop areas as short as possible. This is usually accomplished by grounding digital circuitry as often as possible. Bypass caps and other de-coupling components are also reducing loop area. It is still a debatable topic on whether Digital PC cards should have a single point ground or multipoint. I think in most cases it just depends on the application. But, I think most everyone will agree that getting a good ground connection on both ends of a digital I/O cable is a must. You also need to have a good PE ground connection between equipment and its peripherals or it will have trouble passing the immunity tests you listed below (not to mention possible radiated emissions problems). My advice it this internal to your design you should do a good job of isolating Digital and Analog circuitry to keep digital noise out of your analog. Digital I/O should be grounded well at BOTH ends of the cable providing a good return path for signals and providing a common Earth Reference to between the main unit and the peripherals. Like I said, these are only the basic concepts that apply most of the time. Good luck, Brian Reply Separator Subject:Grounding Author: Praveen Rao List-Post: emc-pstc@listserv.ieee.org Date: 12/6/00 6:52 PM Hello Group, We currently have a system which has modules in a box(metal) with floating digital and analog grounds.It is a Class 1 (safety) equipment. We intend to connect the 0V of each board to protective earth (chassis) at a common single point at the power supply. By doing this, the conducted emissions, ESD, Surges, etc show better results. We have a serial port (DB9)on the device which is only used for configuring Our concern is when a PC is connected to this port, cause in PCs the signal ground (pin 5) is normally connected to PE. So, when a PC is connected to the serial port of our system we may end up with signal grounds on each end of this serial cable connected to it's own device PE. This may cause earth loops. Since this is only a config port, approvals may not be an issue but functionally in the field this may create problems. Is it common to connect digital grounds to a single point chassi ground directly at the power supply ? Should there be any concern from functionality point of view ? especially when a PC is connected to our serial port. Your comments will be greatly appreciated. Praveen Rao --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: Calibration labs
We schedule in advance and usually get 1 week turnaround on cal plus shipping time. We specify 2nd day Fedex. This makes the disruption to our lab scheduling a minimum. Winter can pose some unexpected delays due to weather conditions on the open area test site. Plan your cals for summer when possible. Liberty Labs cal our antennas, LISNs, CDNs, surge generator, ESD simulator, EFT generator. Agilent does our spectrum analyzers. The key to minimum down time is arrangements in advance. > -- > From: Ken Javor[SMTP:ken.ja...@emccompliance.com] > Reply To: Ken Javor > Sent: Tuesday, December 05, 2000 5:53 PM > To: Ray Levasseur; wo...@sensormatic.com; emc-p...@majordomo.ieee.org > Subject: Re: Calibration labs > > > What kind of turn-around times are typical of cal labs? Not just for > antennas but also for items such as spectrum analyzers? Thank you. > > -- > >From: "Ray Levasseur" > >To: wo...@sensormatic.com, emc-p...@majordomo.ieee.org > >Subject: RE: Calibration labs > >Date: Tue, Dec 5, 2000, 3:14 PM > > > > > > > Our company is located in BC on the west coast of Canada and we use > Liberty > > Labs and are very happy with the service and quality. The turnaround > time is > > very reasonable. > > > > Ray Levasseur > > EMC Compliance > > CreoScitex > > > > > >>From: wo...@sensormatic.com > >>Reply-To: wo...@sensormatic.com > >>To: emc-p...@majordomo.ieee.org > >>Subject: RE: Calibration labs > >>Date: Tue, 5 Dec 2000 14:49:40 -0500 > >> > >> > >>Our EMC equipment is calibrated by Liberty Labs (not in California) and > we > >>have been very happy with their pricing and service. > >> > >>Richard Woods > >> > >>-- > >>From: Brian Tan [SMTP:briant20002...@yahoo.com] > >>Sent: Tuesday, December 05, 2000 2:12 PM > >>To: emc-p...@majordomo.ieee.org > >>Subject: Calibration labs > >> > >> > >>Hello; > >>I am looking for a good calibration laboratory to > >>perform the yearly calibration for our instruments. > >>Can anyone tell me which one has good reputation in > >>the California? Right now, we use a lab called > >>Precision Measurement in Northern California and that > >>lab doesn't do a good job. Thanks in advance. > >> > >>Brian > >> > >>__ > >>Do You Yahoo!? > >>Yahoo! Shopping - Thousands of Stores. Millions of Products. > >>http://shopping.yahoo.com/ > >> > >>--- > >>This message is from the IEEE EMC Society Product Safety > >>Technical Committee emc-pstc discussion list. > >> > >>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: > >> Jim Bacher: jim_bac...@mail.monarch.com > >> Michael Garretson:pstc_ad...@garretson.org > >> > >>For policy questions, send mail to: > >> Richard Nute: ri...@ieee.org > >> > >> > >>--- > >>This message is from the IEEE EMC Society Product Safety > >>Technical Committee emc-pstc discussion list. > >> > >>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: > >> Jim Bacher: jim_bac...@mail.monarch.com > >> Michael Garretson:pstc_ad...@garretson.org > >> > >>For policy questions, send mail to: > >> Richard Nute: ri...@ieee.org > >> > >> > > > > > __ > __ > _ > > > > Get more from the Web. FREE MSN Explorer download : > http://explorer.msn.com > > > > > > --- > > This message is from the IEEE EMC Society Product Safety > > Technical Committee emc-pstc discussion list. > > > > 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: > > Jim Bacher: jim_bac...@mail.monarch.com > > Michael Garretson:pstc_ad...@garretson.org > > > > For policy questions, send mail to: > > Richard Nute: ri...@ieee.org > > > > > > --- > This message is from the IEEE EMC Society Product Safety > Technical Committee emc-pstc discussion list. > > 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: > Jim Bacher: jim_bac...@mail.monarch.com > Michael Garretson:pstc_ad...@garretson.org > > For policy questions, send mail to: > Richard Nute: ri...@ieee.org > > --- This message is from the IEEE EMC Society Product Safety Tech
IEEE Standards
I'm wanting to obtain a copy of IEE STD 739-1995 which I know can be downloaded from the IEEE web site. However, I was wondering if, as a member of the British IEE, there is any kind of reciprocal agreement where I can obtain IEEE documents at the IEEE member price. Does anyone know anything about this? All help gratefully received. Nick. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: EN55024
Hi Group, The type of clause (see below) from EN 55022 about adding notes and restrictions to equipment is just the type the European Commission objects against their use in the EN 55022 standard. The reason is that the CENELEC was asked to propose limits and test methods, not to replace politics by limitng the applicability of their standards. The use of such a clause to sell ITE equipment to Class A limits is illegal and will not hold when the presumption of conformity to the essential requirements of the EMC-directive is being tested. Information equipment is and wil be used in all environments, therefore the distinction between such environments is artificial. Regards, Gert Gremmen, (Ing) ce-test, qualified testing === Web presence http://www.cetest.nl CE-shop http://www.cetest.nl/ce_shop.htm /-/ Compliance testing is our core business /-/ === >>-Original Message- >>From: owner-emc-p...@ieee.org [mailto:owner-emc-p...@ieee.org]On Behalf >>Of Pettit, Ghery >>Sent: Tuesday, December 05, 2000 11:46 PM >>To: 'William D'Orazio'; Pettit, Ghery; EMC Posting (E-mail) >>Subject: RE: EN55024 >> >> >> >>OK. EN 55022 is the ITE specific emissions standard. It does >>have two sets >>of limits with a statement that Class B is intended for certain product >>types which may be used in a domestic type environment and a >>statement that >>Class A products should have a warning that they may cause interference if >>used in a domestic environment. CISPR 22 does not use the term >>"industrial" >>to define an environment. It merely warns that the class A limits may not >>provide enough protection to neighboring users of the RF spectrum if the >>device is used in a domestic environment. >> >>Ghery >> >>-Original Message- >>From: William D'Orazio [mailto:dora...@cae.ca] >>Sent: Tuesday, December 05, 2000 2:37 PM >>To: 'Pettit, Ghery'; William D'Orazio; EMC Posting (E-mail) >>Subject: RE: EN55024 >> >> >>BYI, EN55011 should read EN55022. >> >>William D'Orazio >>CAE Electronics Ltd. >>Electrical System Designer >> >>Phone: (514) 341-2000 (X4555) >>Fax: (514)340-5552 >>Email: dora...@cae.ca >> >> >>-Original Message- >>From: Pettit, Ghery [mailto:ghery.pet...@intel.com] >>Sent: Tuesday, December 05, 2000 5:33 PM >>To: 'William D'Orazio'; EMC Posting (E-mail) >>Subject: RE: EN55024 >> >> >>EN 55024 is the ITE specific immunity standard. It is based on CISPR 24 >>which makes no distinction between environments. EN 55011 is >>based on CISPR >>11 and relates to different product families. They do not come from the >>same subcommittees in CISPR, so it's like comparing apples and oranges. >> >>Ghery Pettit >>Intel >> >>-Original Message- >>From: William D'Orazio [mailto:dora...@cae.ca] >>Sent: Tuesday, December 05, 2000 1:22 PM >>To: EMC Posting (E-mail) >>Subject: EN55024 >> >> >> >>Gents, >> >> Why is it that EN55011 defines test levels for both industrial and >>residential environments (class A, B) and EN55024 does not? Are >>the levels >>in EN55024 applicable to all environments (obviously not) so how does one >>define the test levels for an ITE in an industrial environment? >> >>Thanks in advance, >> >> <<...>> >> >>William D'Orazio >>CAE Electronics Ltd. >>Electrical System Designer >> >>Phone: (514) 341-2000 (X4555) >>Fax: (514)340-5552 >>Email: dora...@cae.ca >> >> >>--- >>This message is from the IEEE EMC Society Product Safety >>Technical Committee emc-pstc discussion list. >> >>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: >> Jim Bacher: jim_bac...@mail.monarch.com >> Michael Garretson:pstc_ad...@garretson.org >> >>For policy questions, send mail to: >> Richard Nute: ri...@ieee.org >> >> >> >> >>--- >>This message is from the IEEE EMC Society Product Safety >>Technical Committee emc-pstc discussion list. >> >>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: >> Jim Bacher: jim_bac...@mail.monarch.com >> Michael Garretson:pstc_ad...@garretson.org >> >>For policy questions, send mail to: >> Richard Nute: ri...@ieee.org >> >> <>
Grounding
Hello Group, We currently have a system which has modules in a box(metal) with floating digital and analog grounds.It is a Class 1 (safety) equipment. We intend to connect the 0V of each board to protective earth (chassis) at a common single point at the power supply. By doing this, the conducted emissions, ESD, Surges, etc show better results. We have a serial port (DB9)on the device which is only used for configuring Our concern is when a PC is connected to this port, cause in PCs the signal ground (pin 5) is normally connected to PE. So, when a PC is connected to the serial port of our system we may end up with signal grounds on each end of this serial cable connected to it's own device PE. This may cause earth loops. Since this is only a config port, approvals may not be an issue but functionally in the field this may create problems. Is it common to connect digital grounds to a single point chassi ground directly at the power supply ? Should there be any concern from functionality point of view ? especially when a PC is connected to our serial port. Your comments will be greatly appreciated. Praveen Rao --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
