RE: Constant for Change of Resistance formula.
Hi Robert, Group Yes, this is a known factor for mis-measurement. You must always isolate the component part / winding etc and measure each resistive element to find the individual temperature rises. This is common practice when measuring motor windings, you would take a sample of windings measuring at the brush caps (hot brushes quickly removed) at pre-marked segments on the commutator. This allows you to get a picture of the heat characteristics of a number of windings and hence heat spread throughout the motor windings. Yes, accuracy depends on the resistance being measured but where the formula is applied (motors, relay coils, transformers, solenoids and other mechelec devices), the resistance is high enough to get a good result as long as you follow the guidelines (like those above). Thanks for raising the measurement factors. Bill Ellingford -Original Message- From: Robert Macy [mailto:m...@california.com] Sent: 14 May 2002 02:00 To: Bill Ellingford; emc-p...@majordomo.ieee.org Subject: Re: Constant for Change of Resistance formula. Bill, Big oops. Measuring the resistance to determine the temperature is not productive *unless* the resistance dominates the resistance measurement. Picture three equal valued resistances in a row. The middle one gets very hot (more than 100C rise) and increases over 40%, the two on the edges are heat sinked and barely increase in temperature. The resulting change in resistance is 13% which implies the temperature in there has only gone up around 33C. Measuring the resistance doesn't tell you much. At least with transformers the dominant resistance is pretty much the bulk resistance. - Robert - -Original Message- From: Bill Ellingford bill.ellingf...@motion-media.com To: 'Robert Macy' m...@global.california.com; emc-p...@majordomo.ieee.org emc-p...@majordomo.ieee.org List-Post: emc-pstc@listserv.ieee.org Date: Monday, May 13, 2002 1:56 PM Subject: RE: Constant for Change of Resistance formula. Hi Robert / group OK, Not the best choice of website to demo the answer. The differing figures are because the formula has been transposed to give Temp from change of R from the original formula which gives R from change of T. To do this, another constant (The 234.5 constant) is required. This is the implied point of zero resistance for copper on the Celsius scale. The formula we use is: Rfinal - Rorig x (234.5 + Tamb start) -(Tamb finsh - Tamb start) Rorig The Tamb start and finish are the changes (if any) in Room ambient. If the room remains at 20c then 234.5 + 20 is the multiplier. -Original Message- From: Robert Macy [mailto:m...@california.com] Sent: 13 May 2002 14:54 To: Bill Ellingford; emc-p...@majordomo.ieee.org Subject: Re: Constant for Change of Resistance formula. Bill, Thanks for the site. Went there and found the same formula and constant I use. For copper, Temp Coeff = 3.9 x 10-3 Then I clicked on table of coeff and there was a very long list of materials, but the temp coeff of copper there was 6.8 x 10-3 ???!!! Any ideas for this disparity? - Robert - Robert A. Macy, PEm...@california.com 408 286 3985 fx 408 297 9121 AJM International Electronics Consultants 619 North First St, San Jose, CA 95112 -Original Message- From: Bill Ellingford bill.ellingf...@motion-media.com To: 'Colgan, Chris' chris.col...@tagmclaren.com; emc-p...@majordomo.ieee.org emc-p...@majordomo.ieee.org Date: Monday, May 13, 2002 5:38 AM Subject: RE: Constant for Change of Resistance formula. Hi Folks Further to the answer given, here is a little more data. The constant used is for the change of resistance with temperature. metals and alloys (conductors) all exhibit a different constant. This can be used for calculating temperature rise or resistance change. i.e. find the temp rise from a start and finish test measurement on a winding (for example) at the begining and end of a on load heat run or, find R for a given temp: using a table or the formula, resistance at various temperatures can be pre-determined from a measurement made at one particular temperature. A website with the formulae can be found at http://hyperphysics.phy-astr.gsu.edu/hbase/electric/restmp.html Where you have a transition from one metal type to another, you must measure each metal part individually. If you have only two metals in contact, you may be able to apply a combination of the temp coefficient methods and transposition of the measurement of change of junction voltage formulae i.e. Thermocouple laws. Hope this adds some value: Bill Ellingford -Original Message- From: Colgan, Chris [mailto:chris.col...@tagmclaren.com] Sent: 13 May 2002 10:28 To: emc-p...@majordomo.ieee.org Subject: RE: Constant for Change of Resistance formula. Ned is referring to the constant used in the temperature rise
RE: Constant for Change of Resistance formula.
Hi Robert / group OK, Not the best choice of website to demo the answer. The differing figures are because the formula has been transposed to give Temp from change of R from the original formula which gives R from change of T. To do this, another constant (The 234.5 constant) is required. This is the implied point of zero resistance for copper on the Celsius scale. The formula we use is: Rfinal - Rorig x (234.5 + Tamb start) -(Tamb finsh - Tamb start) Rorig The Tamb start and finish are the changes (if any) in Room ambient. If the room remains at 20c then 234.5 + 20 is the multiplier. -Original Message- From: Robert Macy [mailto:m...@california.com] Sent: 13 May 2002 14:54 To: Bill Ellingford; emc-p...@majordomo.ieee.org Subject: Re: Constant for Change of Resistance formula. Bill, Thanks for the site. Went there and found the same formula and constant I use. For copper, Temp Coeff = 3.9 x 10-3 Then I clicked on table of coeff and there was a very long list of materials, but the temp coeff of copper there was 6.8 x 10-3 ???!!! Any ideas for this disparity? - Robert - Robert A. Macy, PEm...@california.com 408 286 3985 fx 408 297 9121 AJM International Electronics Consultants 619 North First St, San Jose, CA 95112 -Original Message- From: Bill Ellingford bill.ellingf...@motion-media.com To: 'Colgan, Chris' chris.col...@tagmclaren.com; emc-p...@majordomo.ieee.org emc-p...@majordomo.ieee.org List-Post: emc-pstc@listserv.ieee.org Date: Monday, May 13, 2002 5:38 AM Subject: RE: Constant for Change of Resistance formula. Hi Folks Further to the answer given, here is a little more data. The constant used is for the change of resistance with temperature. metals and alloys (conductors) all exhibit a different constant. This can be used for calculating temperature rise or resistance change. i.e. find the temp rise from a start and finish test measurement on a winding (for example) at the begining and end of a on load heat run or, find R for a given temp: using a table or the formula, resistance at various temperatures can be pre-determined from a measurement made at one particular temperature. A website with the formulae can be found at http://hyperphysics.phy-astr.gsu.edu/hbase/electric/restmp.html Where you have a transition from one metal type to another, you must measure each metal part individually. If you have only two metals in contact, you may be able to apply a combination of the temp coefficient methods and transposition of the measurement of change of junction voltage formulae i.e. Thermocouple laws. Hope this adds some value: Bill Ellingford -Original Message- From: Colgan, Chris [mailto:chris.col...@tagmclaren.com] Sent: 13 May 2002 10:28 To: emc-p...@majordomo.ieee.org Subject: RE: Constant for Change of Resistance formula. Ned is referring to the constant used in the temperature rise calculated by change in resistance formula ie ... Where dt is the temperature rise, R1 is start resistance, R2 is end resistance, T1 is start ambient and T2 is end ambient. 234.5 is the formula constant for copper. This formula is used extensively when heat testing transformers and coils. I'm afraid I don't know the constant for brass but I believe the figure may be related to the inferred absolute zero of a material. Try asking a metallurgist? Regards Chris Colgan Compliance Engineer TAG McLaren Audio Ltd The Summit, Latham Road Huntingdon, Cambs, PE29 6ZU *Tel: +44 (0)1480 415 627 *Fax: +44 (0)1480 52159 * Mailto:chris.col...@tagmclaren.com * http://www.tagmclaren.com -Original Message- From: Robert Wilson [SMTP:robert_wil...@tirsys.com] Sent: Friday, May 10, 2002 7:00 PM To: emc-p...@majordomo.ieee.org; Ned Devine Subject: RE: Constant for Change of Resistance formula. What are the units? 234.5 ...what?? Looking at what the units are, will basically tell you exactly what the property is related to. Nonetheless, you cannot possibly directly determine what the temperature change of something as physically and geometrically complex as a connector, merely by factoring in what its resistance change is. Among other things, the solution is extremely non-linear and iterative. Changing resistance will generate more heat, which will increase temperature, which will generate even more heat and on and on! Add this to the fact the resistance coefficient with temperature is itself non-linear, and you can see how this complicates things further. The final temperature that the system stabilizes at, is reached when the logarithmically increasing (i.e. also very non-linear) heat transfer to the environment caused by increasing temperature, balances increased heat being generated. To reach a solution, you need to iterate your calculations, where the results of one calculation are plugged as variables
RE: Constant for Change of Resistance formula.
Hi Folks Further to the answer given, here is a little more data. The constant used is for the change of resistance with temperature. metals and alloys (conductors) all exhibit a different constant. This can be used for calculating temperature rise or resistance change. i.e. find the temp rise from a start and finish test measurement on a winding (for example) at the begining and end of a on load heat run or, find R for a given temp: using a table or the formula, resistance at various temperatures can be pre-determined from a measurement made at one particular temperature. A website with the formulae can be found at http://hyperphysics.phy-astr.gsu.edu/hbase/electric/restmp.html Where you have a transition from one metal type to another, you must measure each metal part individually. If you have only two metals in contact, you may be able to apply a combination of the temp coefficient methods and transposition of the measurement of change of junction voltage formulae i.e. Thermocouple laws. Hope this adds some value: Bill Ellingford -Original Message- From: Colgan, Chris [mailto:chris.col...@tagmclaren.com] Sent: 13 May 2002 10:28 To: emc-p...@majordomo.ieee.org Subject: RE: Constant for Change of Resistance formula. Ned is referring to the constant used in the temperature rise calculated by change in resistance formula ie ... Where dt is the temperature rise, R1 is start resistance, R2 is end resistance, T1 is start ambient and T2 is end ambient. 234.5 is the formula constant for copper. This formula is used extensively when heat testing transformers and coils. I'm afraid I don't know the constant for brass but I believe the figure may be related to the inferred absolute zero of a material. Try asking a metallurgist? Regards Chris Colgan Compliance Engineer TAG McLaren Audio Ltd The Summit, Latham Road Huntingdon, Cambs, PE29 6ZU *Tel: +44 (0)1480 415 627 *Fax: +44 (0)1480 52159 * Mailto:chris.col...@tagmclaren.com * http://www.tagmclaren.com -Original Message- From: Robert Wilson [SMTP:robert_wil...@tirsys.com] Sent: Friday, May 10, 2002 7:00 PM To: emc-p...@majordomo.ieee.org; Ned Devine Subject: RE: Constant for Change of Resistance formula. What are the units? 234.5 ...what?? Looking at what the units are, will basically tell you exactly what the property is related to. Nonetheless, you cannot possibly directly determine what the temperature change of something as physically and geometrically complex as a connector, merely by factoring in what its resistance change is. Among other things, the solution is extremely non-linear and iterative. Changing resistance will generate more heat, which will increase temperature, which will generate even more heat and on and on! Add this to the fact the resistance coefficient with temperature is itself non-linear, and you can see how this complicates things further. The final temperature that the system stabilizes at, is reached when the logarithmically increasing (i.e. also very non-linear) heat transfer to the environment caused by increasing temperature, balances increased heat being generated. To reach a solution, you need to iterate your calculations, where the results of one calculation are plugged as variables into the next iteration. Typically a thermal analysis program will require several hundred iteration before a converged solution results. Bob Wilson TIR Systems Ltd. Vancouver. -Original Message- From: Ned Devine [mailto:ndev...@entela.com] Sent: May 10, 2002 8:29 AM To: emc-p...@majordomo.ieee.org Subject: Constant for Change of Resistance formula. Hi, Does any one know how the constant for CoR formula was determined? I know the K is 234.5 for copper and 226 for aluminum, but what property is this related to? I am trying to determine the change in temperature of a connector, based on the change of resistance. The connector contacts are made of brass. Thanks Ned Ned Devine Program Manager Entela, Inc. 3033 Madison Ave. SE Grand Rapids, MI 49548 1 616 248 9671 Phone 1 616 574 9752 Fax ndev...@entela.com e-mail Entela, Inc. A Certified Woman Owned Business www.entela.com ** Please visit us at www.tagmclaren.com ** The contents of this E-mail are confidential and for the exclusive use of the intended recipient. If you receive this E-mail in error, please delete it from your system immediately and notify us either by E-mail, telephone or fax. You should not copy, forward or otherwise disclose the content of the E-mail. TAG McLaren Audio Ltd The Summit, 11 Latham Road Huntingdon, Cambs, PE29 6ZU Telephone : 01480 415600 (+44 1480 415600) Facsimile : 01480 52159 (+44 1480 52159
RE: RTTE Directive
Hi Group, John etc. The RTTE has provision Network Access essential requirements (for wired products) to be added if the commission find a need. Currently, there are no requirements except for those added to cover France Telecom. Parts of the French POTs network use old technology where certain transformers (possibly A type relays) become saturated and thus will not pass any audio if the line current drawn exceeds 60mA. For an interim period, the commission have included the Line feeding tests (60mA current limit) from TBR21 as an applicable, essential requirement for France. There is a withdrawal date for this requirement so it to will soon vanish. I agree with John, many sales chains are unhappy taking product with no network access test results, we therefore choose to voluntarily apply the TBR standards as a means of demonstrating compliance with the former, applied essential requirements to show to any interested parties. This testing can of course be of further benefit, as many reports can be used in other countries to support an overseas approval application. This is particulalry true of more modern technologies like ISDN BRI and PRI, ONP etc. A good example of this is TBR3 which is widely accepted as the Euro / CEPT ISDN test standard. Investigate the standards you apply as part of any One stop multi-country approvals strategy. I also agree that other, design standards may be applied. The directive calls for all PTOs to provide a list of interface specifications for the ports available on their networks. Many PTOs are quoting earlier national specification for this purpose (I see some BS specs on the BT site) and many refer to the NETs and TBRs from previous years. Do not forget that Wireless interfaces do still have connection requirements under the directive, where possible these are harmonised (ETSI) but due to deviation in frequency allocations and terrain, many remain based on National standards. This is only a brief answer, obviously there is a lot more content in the actual body of the directive. This should be essential (but not bed time) reading for this subject! the 99/5/EC directive can be downloaded from our favourite EUROPA server. Hope this helps. Best regards Bill Ellingford Approvals Conformance manager Motion Media Technology Ltd -Original Message- From: j...@aol.com [mailto:j...@aol.com] Sent: 08 May 2002 17:06 To: jjuh...@fiberoptions.com Cc: emc-p...@majordomo.ieee.org Subject: Re: RTTE Directive In a message dated 5/8/2002, John Juhasz writes: it appears that it is not required to test the interface itself to 'telecom specs' such as those in the CTR21. Hi John: Your interpretation is correct. For wireline POTS products/interfaces, the only requirements that apply under the RTTE directive are safety and EMC. There are no regulatory requirements whatsoever for the type of specifications called out in CTR 21. CTR 21 ceased to be a regulatory requirement when the RTTE directive came into force on April 8, 2000. That being said, many manufacturers are uncomfortable with having no regulatory requirements for telecom. One option is to continue voluntary testing to CTR 21. Another option is to obtain the individual reference standards that the RTTE directive requires each operator of a public network to publish. Most of the major operators have posted these on their web sites. A third option is to review CTR 21 and the relevant reference specifications, then use engineering judgment to design and test your interface. This is the preferred approach if you are seeking minimum cost and/or maximum compatibility with the various national networks. The bottom line is that the telecom aspects of your product performance are now a matter between you and your customer, rather than between you and the regulators. Joe Randolph Telecom Design Consultant Randolph Telecom, Inc. 781-721-2848 http://www.randolph-telecom.com *
Employment
Hi Guys I have been a member of these interest groups for some time and a once regular contributor to Treg. Please allow me to question job opportunities in the Bristol / S Wales area UK. I attach a brief resume. Please skip this message if this is outside your scope. Many thanks to anyone who can offer any leads, info, help etc. I am seeking employment opportunities in the ITT industry, preferably around the Bristol, South Wales borders region UK. I am currently working as Approvals and Conformance Manager with specialised knowledge in the Telecom domain. My work covers Safety, EMC and Network access as well as monitoring global change and EU directives. My role also touches on HS. I support the company and its distributors on approvals and certification exercises in most global regions but most often USA, Canada, EU, S Africa and Australasia. I project manage multiple submissions for a range of products and enhancements and advise at design stage on product construction. I also manage a database of Compliance Affecting Parts to assist submissions with UL. In addition to the compliance side, I also currently manage the company conformance test schedules, checking manufactured devices meet operational and functional specs. I also provide advice and test methodology for POT's, ISDN (BRI and PRI), X.21, X.25 E1, E2, E3 (and T1). In the past I have worked in the standards industry including participation in standards development, I have also worked as a consultant in standards and compliance engineering for many years before moving for a more settled role within industry. I have a young family, hence my preference to stay in the Glos / Bristol / Newport region. I would be very pleased to hear from anyone within the group with news on any possible openings / positions in this area. Bill Ellingford Approvals / Conformance Manager, Motion Media Technology Ltd company E-mail address valid until 17 May 02 * --- 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com 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://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
RE: A very nice game
URGENT Please be aware that the above E-mail to the EMC group contained a virus. Fortunately our system removed it from the message. Bill Ellingford -Original Message- From: jmw [mailto:j...@jmwa.demon.co.uk] Sent: 24 April 2002 22:59 To: emc-p...@ieee.org Subject: A very nice game -- Virus Warning Message (on gemini2) setup.exe is removed from here because it contains a virus. - * --- 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com 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://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
RE: product modifications by the end user
Hi Folks Safety compliance for an add-in card is not an impossibiity! You can follow EN 60950 and come up with a compliant product design which allows user access to internal SELV status parts. This is often the case with PC's. You may then design a card for installation within such a product which, together with the installation instructions, is deemed a compliant product. The same is true of certain games machines having SELV cartridge ports where a cover is removed allowing expansion memory etc. to be fitted. PCs designed in this way often require no tools to remove the access cover, some have knurled nuts or twist locks. I even beleive there is a UL scheme (although I haven't checked for a few months) to cover PCs designed in this way and also a scheme to cover a UL Listed Accessory card for use in these. This scheme includes the documentation in the listing. There may still be some EMC issues to address but safety compliance is not impossible! Bill Ellingford -Original Message- From: geor...@lexmark.com [mailto:geor...@lexmark.com] Sent: 19 March 2002 14:26 To: Colgan, Chris Cc: 'Emc-Pstc' (E-mail) Subject: Re: product modifications by the end user Chris, Every set of existing rules has an intent, to be achieved by following the letter of the rules. Personally, I always consider meeting the intent far superior to meeting the letter of rules. Example, the letter of the law says we must stop at stop signs before proceeding. The intent is to avoid accidents. We all know that sometimes we must exceed the rules, i.e. defensive driving, because the situation demands it. We also know that if the stop sign is in the middle of a desert, and we can see 5 miles in all directions, one would be meeting the intent of the law if no other cars could be seen, an we did not stop at the sign. The intent of IEC 60950 and like standards is to avoid personal injury and property damage. End users are generally considered operators under the standard. As such, they are to be reasonably prevented from access to hazards in the equipment. This does not mean that the equipment must be in a welded steel box, but that tools are required to enter hazardous areas, and the operator manual does not direct the operator to access such areas. The General Principles of 60950 (page 19) clearly states under Electric Shock : Prevent operator access to parts at hazardous voltage by fixed or locked covers, interlocks, etc. Page 17 indicates that operators are assumed to be oblivious to electrical hazards. When all else fails in such situations as yours, I get something in writing indicating that my team has explained the hazards and risks, and the the Product Manager (or other responsible party) understands and accepts these risks. This usually closes the issue. George Colgan, Chris chris.colgan%tagmclaren@interlock.lexmark.com on 03/19/2002 07:36:09 AM Please respond to Colgan, Chris chris.colgan%tagmclaren@interlock.lexmark.com To: 'Emc-Pstc' (E-mail) emc-pstc%majordomo.ieee@interlock.lexmark.com cc:(bcc: George Alspaugh/Lex/Lexmark) Subject: product modifications by the end user Hello good people Just say someone in your marketing department came up with the bright idea of selling upgrade kits to an unqualified, untrained end user that involved removing the top cover of a product. In the process not only would the victim be exposed to hazardous voltages (if the product was still connected to the mains) but he/she would also have to wire up mains connections. There would also be a possibility that critical insulation would be disturbed. Apart from telling them that they were mad and suggesting that someone could be killed or seriously injured, would there be any black and white legislation that you could use to help bin this idea? I can't find anything specific in EN60065 or the LVD. Thanks for any input Chris Colgan Compliance Engineer TAG McLaren Audio Ltd The Summit, Latham Road Huntingdon, Cambs, PE29 6ZU *Tel: +44 (0)1480 415 627 *Fax: +44 (0)1480 52159 * Mailto:chris.col...@tagmclaren.com * http://www.tagmclaren.com --- 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@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://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list * --- This message is from the IEEE EMC
RE: CE Mark on Product Packaging
Hi Guys My wording may have been put together in haste however, I think the important part of the directive is the word OR. The manufacturer OR his authorised representative, established within the community. I had always beleived this was interpreted as one or the other must be within the EEC (now EU). This does differ from the RTTE requirement and is the basis for the differing needs to CE mark packaging. I am of course interested in other views on this interpretation. Bill Ellingford -Original Message- From: Scott Lemon [mailto:sle...@caspiannetworks.com] Sent: 15 March 2002 14:43 To: emc-pstc Cc: Bill Ellingford; 'Russell' Subject: Re: CE Mark on Product Packaging Correct me if I am wrong, but I do not believe the statement below is entirely correct. It is my understanding (per EMC directive and published guidelines) that the Manufacturer or Authorized Representative is responsible for affixing the CE marking and drawing up the DoC and that only the Authorized Rep (if applicable) must be established within the community. In other words, the Manufacturer (who draws up the DoC and tech docs) does not have to be established in the community, but if an Authorized Rep is used, they must be. It is clear that when neither the Manufacturer or the Auth Rep are established within the community, the obligation to keep the DoC available is the responsibility of the party placing the product on the market (importer). Scott Lemon Caspian Networks Bill Ellingford wrote: Under the EMC directive, the person making a DOC and placing the goods on the market would be an EU resident. --- 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@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://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list * --- 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@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://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
RE: Voltage Spikes on Power Lines etc
One clear piece of evidence is that safety standards committees always specify much larger creepage and clearance distances for externaly supplied hazardous voltages than for those generated within a product. A good example are the two sets of tables in IEC or EN 60 950. This is to accomodate high voltage spikes and lightning induced voltages etc. Bill Ellingford -Original Message- From: George Stults [mailto:george.stu...@watchguard.com] Sent: 14 March 2002 17:17 To: emc-p...@majordomo.ieee.org Subject: Voltage Spikes on Power Lines etc Hi Folks, I am trying right now to convince some folks that power line voltage spike problems can be and usually are severe enough to degrade or kill ITE products that don't have adequate over-voltage protection. I found a link using Google that describes the problems [ http://www.kalglo.com/powrline.htm ] but I'm looking for additional links to specifics or summaries if any one knows of such. Thanks in advance. George S. --- 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@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://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list * --- 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@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://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
RE: CE Mark on Product Packaging
I beleive the change in stance is due to the change in requirement regarding a European presence. Under the EMC directive, the person making a DOC and placing the goods on the market would be an EU resident. The RTTE allows parties outside of the EU to make the DOC and hold the Technical file, it is the person placing product on the market who carries legal liability. This means that goods can be imported into the EU with the CE declaration so marking the packaging resolves customs issues in these circumstances. Bill Ellingford -Original Message- From: Russell [mailto:r@totalise.co.uk] Sent: 14 March 2002 15:39 To: emc-pstc Subject: CE Mark on Product Packaging Does anybody know why the placing of the CE mark on product packaging is compulsory under the RTTE Directive, yet optional under the EMC and LVD Directives? Or am I wrong? Only curious, Russell. --- 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@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://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list * --- 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@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://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
RE: RTTE and video out
Difficult one to call but this device may be subject to RTTE as, depends on how it is connected and used. It will probably have a 75 Ohm output which will match a TV antenna impedance and thus be capable of transmitting (albeit a short distance). Can you get around this with warnings in the User Guide? Bill Ellingford -Original Message- From: Kim Boll Jensen [mailto:kimb...@post7.tele.dk] Sent: 13 March 2002 10:49 To: EMC-PSTC; treg Subject: RTTE and video out Hi all I have an equipment which can convert audio and video (phono connector) signal from a PC to a normal HF antenna signal which can be transmitted though a normal antenna cable in the house to your radio and TV sets. The voltage of the HF signal is the same as normal received from an antenna. Does this product fall under the RTTE directive ? According to my interpretation the definitions in art. 2 c) and d) say that it has to be used for TX to be under this directive. What do you think ? Best regards, Kim Boll Jensen Bolls Raadgivning Denmark *
RE: ventilation holes
Hi Gregg I had a look at the safety test and beleive there are some incorrect Q A's regarding European mains voltages. One Q asks if the Euro mains is 220v. Another later question asks is the Euro mains 240v. Both of these are incorrect, a directive on harmonisation of mains supplies calls for most EU countries to adjust their mains volatge by increasing from 220 to 230 whilst UK and Eire are to adjust downward from 240 to 230. Have any of my UK colleagues stuck a DMM across their mains recently, both my Home and works supplies have been set at 230v now. Not sure how up to date the rest of EU are with these plans? Also, the question re: does UL listing for a product at 240v ensure Euro safety compliance? Yes, it can do now since the adoption of the latest IEC 60950 as UL 60950, providing you ask for EU deviations. Maybe the test needs updating or have I missed something by not requesting the answers??? Bill Ellingford -Original Message- From: Gregg Kervill [mailto:gkerv...@pgtv.net] Sent: 27 February 2002 02:06 To: 'George Stults'; emc-p...@majordomo.ieee.org Subject: RE: ventilation holes Please have a look at http://www.test4safety.com/html/elearning.htm for some of the free downloadable training aids. The one that you need is ES/2001/PHYSMECH/D 005 The Understanding Product Safety - series - Physical and Mechanical Considerations There is also a test on the home page for anyone brave enough! Best reagrds Gregg PLEASE NOTE: We are currently experiencing serious problems with our service provider PLEASE reply only to gr...@test4safety.com mailto:gr...@test4safety.com and ignore any reference to pgtv.net, Thank you. --Original Message- -From: owner-emc-p...@majordomo.ieee.org -[mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of George Stults -Sent: Tuesday, February 26, 2002 1:24 PM -To: 'emc-p...@majordomo.ieee.org' -Subject: ventilation holes - - - -Hi Folks, - -I have a safety question for the group. I have a small -(about 8 x 10 x 2 -inch) piece of ITE equipment, SELV, enclosed in a plastic -case, powered by -an external 12 volt brick from AC mains. - -The problem is, the device tends to run a little hotter than -desired. One -proposed solution is to cut some vent holes in the top. -These would be -roughly (1/2) inch long by (1/6) inch wide, spaced (1/4) inch apart, -running across the top near the front of the device. - -I haven't seen many (any?) devices with vent holes in the top, so I'm -wondering if there is a basic reason why not, such as the -cover must shed -water, etc. -My questions are, what considerations arise and what sections -of EN 60950 -apply to this, either to allow it or to exclude it. - -Thanks in advance - -George S. - - -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: - Ron Pickard: emc-p...@hypercom.com - Dave Heald: davehe...@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://ieeepstc.mindcruiser.com/ -Click on browse and then emc-pstc mailing list --- 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@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://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list * --- 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@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
RE: Different shades of UL
A very quick and basic summary: Very roughly speaking, the UL marks can be interpretted as follows. (OK there are pages and pages of jargon attached to each but the quick messy answers are): the UL, UL listed and CUL listed products are those that have been tested at a UL test facility and passed the relevant applicable product tests (safety) for such a device. The CUL denotes listing is acceptable to UL and harmonised Canadian standards. The list info and file will outline the standard applied (maybe UL1950 / UL60950) and models of the equipment covered. Such listed devices are manufactured at UL inspected factory facilities. The mirror image logo is applied to components and parts for which UL have a manufacturing scheme. This means parts marked with the logo have been tested using UL inspected methods and under a UL checked quality system. This could be on a cable such a a VW-1 rated cord or a PCB with V0 Rating etc. Adopting logo marked parts for use in a UL listed product makes for easier tracability of critical components. There is also a UL listed Accessory which is for devices intended to be installed in a host (like a card for a PC). This is like the UL, CUL mark but requires installation instructions as part of the assessment. Hope this helps: Bill Ellingford Approvals and Compliance manager Motion Media Technology -Original Message- From: Chris Maxwell [mailto:chris.maxw...@nettest.com] Sent: 22 February 2002 14:40 To: EMC-PSTC Internet Forum Subject: Different shades of UL Hi all, I know that this has been covered before. But please indulge my ignorance. There are many different forms of UL marks, each with subtle differences. There is the UL in a circle. There is also the mirror lettered RU. There are also some subscripts denoting approval for Canada as well. There may be some other variations that I can't remember. Anyone care to blow a few minutes on a Friday afternoon to explain which symbol means what? Thanks, Chris Maxwell | Design Engineer - Optical Division email chris.maxw...@nettest.com | dir +1 315 266 5128 | fax +1 315 797 8024 NetTest | 6 Rhoads Drive, Utica, NY 13502 | USA web www.nettest.com | tel +1 315 797 4449 | --- 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@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://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list * --- 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@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://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
RE: Packaging vs. Shipping Container
Hi Treg world Re CE mark, The mark allows the free movement of goods within the EU and EFTA nations. This is because it is indicating conformity against certain directives, which apply throughout the union. Therefore, if a product falls within the category of a directive, it requires the mark even if only sold in one member state. This legislation will become even more important under the new RTTE directive 99/5/EC. When CE marking a product, you are also declaring conformity against the applicable directives (interested parties may request a copy of this declaration). A product that does not meet any directives would not be CE marked. This could occurr for items that do not fall within the scope of current directives otherwise for products that do, the product would be non-conformant. Most things electrical will fall under either the EMC directive or the Low Voltage Directive and thus require CE marking to show conformity. SES and TTE fall under the SESTTE directive which is also linked to the harmonised use of the CE mark. Note also that when the RTTE comes into force, the LVD is to be changed such that electrical safety requirements apply to any RTTE product. The mark may be prominently displayed on packaging to assist European customs. It does not need to be placed on shipping containers as these are allowed to be opened and inspected under customs legislation. This is a slightly rushed response so I appologise if it is not well worded. The scope I believe to be accurate but I welcome others to join in on this one. Bill Ellingford. Approvals Manager Motion Media Technology Ltd -- From: colin_mcgeec...@hp-unitedkingdom-om4.om.hp.com[SMTP:colin_mcgeec...@hp-unitedkingdom-om4.om.hp.com] Sent: 23 June 1999 15:16 To: mschm...@xrite.com Cc: t...@world.std.com Subject:RE: Packaging vs. Shipping Container Richard, Mark, I have to disagree, the intention of the CE mark is to show compliance with European Directives (those applicable), it allows free movement of goods across the EU borders. It's intention is not to provide the consumer with information so that they can make an informed purchasing decision. I would suggest that a product can be designed, manufactured and sold within one European Country without having the CE mark applied. It may well be within the scope of some European Directive, but as long as it does not cross any National Border then the CE mark is not required, so long as it meets the local regulations. Why would Joe Public care if his pc printer had a CE mark as long as it gives good quality prints and doesn't interfere with his TV set. You're mixing customer needs with regulatory requirements. I'd say put the mark on any of the packaging you see fit, as long as you can back this up with some rational. If a customs inspector isn't satisfied with the markings on the shipping container, they'll keep peeling the layers until they find what they are after. Cheers, Colin. __ Reply Separator _ Subject: RE: Packaging vs. Shipping Container Author: Non-HP-MSchmidt (mschm...@xrite.com) at HP-UnitedKingdom,mimegw6 List-Post: emc-pstc@listserv.ieee.org Date:06/23/99 2:29 PM Richard, I agree. Your definitions are very rational. Regards, Mark Schmidt mschm...@xrite.com mailto:mschm...@xrite.com Phone: (616) 257-2469 X-Rite Incorporated 3100 44th Street, S. W. Grandville, Michigan 49418 USA Website - www.x-rite.com http://www.x-rite.com -Original Message- From: WOODS, RICHARD [SMTP:wo...@sensormatic.com] Sent: Wednesday, June 23, 1999 8:49 AM To: 'emc-pstc'; 'treg' Subject:Packaging vs. Shipping Container Various EU Directives require certain information to be placed on the packaging of a product. However, packaging is not defined. The intent of the requirements appears to be to provide the consumer with information so that they can make an informed purchasing decision. Please put on your lawyer's hat and tell me if the following definitions are reasonable to distinguish packaging from a shipping container for compliance marking purposes. Shipping Container: A protective container in which a product is placed for shipping purposes. The container is not intended for public display of the product such as in a retail store, nor is it intended to convey product information to the consumer; therefore, displayed product information may be limited. The product in the shipping container may or may not be enclosed in packaging. Products intended to be shipped direct to the end user may not include packaging. Packaging: A container in which the product is placed for public display purposes in retail shops and similar stores
RE: E M terminology . . . .
Hi Treg Barry! good to see you in text coming through the Ether. You said sorry, I was wrong but you have a definition Earth and Magneto. This is the same as my Earth and Make to Battery! I rest my case m'lord. I do believe Ear and Mouth are the most commonly used words but maybe not the correct ones. Bill Ellingford -- From: Barry C. Quinlan[SMTP:bsi_little...@csi.com] Sent: 16 June 1999 19:23 To: t...@world.std.com Subject:Re: E M terminology . . . . The definition in the 15th Edition of Newton's Telecom Dictionary is: Ear Mouth Earth and Magneto rEceive and transMit So it appears everyone is right except Bill. Sorry Bill. Best Regards Barry C. Quinlan Manager BSI Product Services (USA) Tel: 978 486 4666 x270 Fax: 978 486 8600 - Original Message - From: Bill Ellingford bill.ellingf...@motionmedia.co.uk To: t...@world.std.com Sent: Wednesday, June 16, 1999 1:32 PM Subject: RE: E M terminology . . . . Hi Treg In the back of my mind (probably where it should remain) something tells me that E M referred to the function i.e Earth Lead and Make Lead. Make being pulsed battery (positive or negative) and earth being the detector circuit to ground. I can confirm that it is used for PW CCT pulse signalling against international signalling sytems SSDC5 and SSDC10. Feasible? Bill Ellingford Motion Media Technology -- From: kkee...@host.igs.net[SMTP:kkee...@host.igs.net] Sent: 16 June 1999 11:57 To: t...@world.std.com Subject: RE: E M terminology . . . . Your Wrong! application/ms-tnef
