RE: TNV Test Currents
Pete Tarver pointed out that: >>>The primary protector at a building entrance limits the voltages available to do harm to 600Vrms (assumed sinusoidal). There might also be secondary protection on telecommunication lines that include supplemental overvoltage protection that limits the voltage downstream to even lesser levels. Another concern is that in the event of a lightning strike or power cross, an overvoltage device on the equipment side rated lower than 600 V will fire before the 600V outside protector, shunting all follow-current through the unprotected premesis wiring and through the equipment itself. Greg Galluccio www.productapprovals.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...@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: TNV Test Currents
Greg - It is important to note that secondary protectors, by definition in both North American and ITU-T specifications, are overcurrent protection devices. I did mentioned that the additional overvoltage protection was included, but not that it was the only protection in the secondary protector. Assuming the secondary protector is installed correctly, if the overvoltage protection in the secondary protector were to activate (spark over), the secondary protector's overcurrent protection would open the circuit (usually on the order of 350mA, further protecting the premises wiring and terminal equipment. Then the brunt of the power cross would be taken by the primary protector. Regards, Peter L. Tarver, PE Product Safety Manager Sanmina-SCI Homologation Services 2000 Ringwood Ave. San Jose, CA 95131-1749 V: 408-904-2081 F: 408-904-2095 M: 408-234-3529 peter.tar...@sanmina-sci.com > -Original Message- > From: Greg Galluccio > Sent: Friday, December 13, 2002 11:50 AM > > Pete Tarver pointed out that: > > >>>The primary protector at a building entrance > limits the voltages available > to do harm to 600Vrms (assumed sinusoidal). > There might also be > secondary protection on telecommunication lines > that include > supplemental overvoltage protection that limits > the voltage > downstream to even lesser levels. > > Another concern is that in the event of a > lightning strike or power cross, an > overvoltage device on the equipment side rated > lower than 600 V will fire > before the 600V outside protector, shunting all > follow-current through the > unprotected premesis wiring and through the > equipment itself. > > > Greg Galluccio > www.productapprovals.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...@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" --- 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: Location of CE DoCs - electronic copies
I read in !emc-pstc that Gregg Kervill wrote (in <004201c2a2cb$92934120$7100a8c0@MENHADEN>) about 'Location of CE DoCs - electronic copies' on Fri, 13 Dec 2002: >I think one of us may have missed or failed to see the point - John, you >seem to have disagreed with what I wrote and then agreed with what I thought >I said. > > > >What I am saying is that if the product changes SIGNIFICANTLY from the >original TYPE-TEST model, in safety (or EMC) terms, then re-testing WILL be >necessary. Misunderstandings happen. It seemed to me that discussing the dire consequences of 'changes' without describing the change-control procedure gave a very scary impression. I'm glad that we actually agree. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! --- 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"
HV Relay for you
Brian, Ross Engineering Corp. (http://www.rossengineeringcorp.com/) has relays that will satisfy your creepage distance requirements. Dave Cuthbert Signal Integrity/EMC/Analog Engineer Micron Technology -- Replies to this message may be posted in the following public forum: High Voltage Relay HELP!!! (http://ieeepstc.mindcruiser.com/direct/topic/a/ID544592)
RE: Location of CE DoCs - electronic copies
I think one of us may have missed or failed to see the point - John, you seem to have disagreed with what I wrote and then agreed with what I thought I said. What I am saying is that if the product changes SIGNIFICANTLY from the original TYPE-TEST model, in safety (or EMC) terms, then re-testing WILL be necessary. Obviously if there is a technical justification for a change to SAFETY Critical components then that becomes part of the CE Marking File. The methodology that I described you refer to (I think) as "Due Diligence" - as per the EU Directives. But that term has no 'strict' definition - therefore it does not (I believe) help those trying to understand what they NEED to do. What I have attempted was to outline a methodology that can be audited to provide a valid traceability of change, of technical reconciliation AND evidence that "Due Diligence" has taken place. Without a documentation trail then all that exists are mere words - and they will not hold any substance in Court. Doing this DOES NOT take a significant amount of time - in fact it reduces time spent in reviews because everyone knows what is being discussed and can make a TECHNICAL judgment. If this methodology (or something like it) is not followed then there will be endless discussion - no record of changes that affect how safety is put in place (leaving a hole into which some poor design engineer will later fall). Oh, and by the way - it may also destroy any defense that the Corporation might have wished to use in the future. I know that I keep quoting the UL/CSA model for manufacturing control - but it works exceeding well in products that have only are self certified and CE Marked. The Best reason of all for using this methodology is that it has been working for a great many years. I have used it for more than 10 years and I think that UL might have been using it a little longer :*} A formal methodology gives an easy (and obvious) method of change control - an easy method of modification and a record of what has been done. This is particularly important when a 'new' engineer needs to change Critical Components things that affect Safety or EMC - because without such a system in place someone WILL make an expensive mistake. And Finally - it is part of ISO9001 anyway! Best regards Gregg -Original Message- From: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of John Woodgate Sent: Friday, December 13, 2002 5:00 AM To: emc-p...@majordomo.ieee.org Subject: Re: Location of CE DoCs - electronic copies I read in !emc-pstc that Gregg Kervill wrote (in <004901c2a1ee$e45d66d0$7100a8c0@MENHADEN>) about 'Location of CE DoCs - electronic copies' on Thu, 12 Dec 2002: >There is a problem with "..the reader is guaranteed to get the latest >revision as stored in our Document Control system." > >The latest drawing has NO RELEVANCE WHATEVER to the CE Marking File. What we >are required to record is the "As Built Standard" of the product tested - in >terms of its Safety or EMC performance. > >It is for precisely this reason that UL/CSA/et al use specially written >Product Descriptions to allow manufacturing follow-up inspection. > >Evaluation for safety (and EMC) relates to ONE PRODUCT (the type-test model) >- if current production standard deviates significantly (in safety or emc >terms) from that original type-test model then re-evaluation is required to >limit potential corporate liability. This is an exceedingly stringent and impracticable interpretation. Of course, engineering changes are not prohibited, which is what seems to be implied. Due diligence can be demonstrated if each change is evaluated by a competent person to *determine* whether re-testing (which can be limited re-testing) is required or not. This is precisely the purpose of keeping the technical file, which should record all such evaluations -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! --- 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" --- This message is from the IEEE EMC Society Product Safe
RE: TNV Test Generator
Sam - Your post was no doubt sent before I replied to John Allen. FWIW, I'll try to add some clarity on the power cross testing. The power lines that are collocated with telecommunication lines are typically medium voltage. There are both induced voltages into and metallic power cross to the telecommunication lines. The primary protector at a building entrance limits the voltages available to do harm to 600Vrms (assumed sinusoidal). There might also be secondary protection on telecommunication lines that include supplemental overvoltage protection that limits the voltage downstream to even lesser levels. The 120V and 240V power cross tests are to simulate someone digging and tearing through both a branch circuit and a telecommunication line in a stroke. While much of the telecommunications infrastructure is buried, I hesitate to say "most" is. In most new construction since ~1970, perhaps earlier, it is. It certainly isn't in my parents' neighborhood; or probably most older neighborhoods and business districts, especially those that are less wealthy than others. Regards, Peter L. Tarver, PE Product Safety Manager Sanmina-SCI Homologation Services San Jose, CA peter.tar...@sanmina-sci.com > From: Sam Davis > Sent: Thursday, December 12, 2002 7:56 AM > > In the US, aren't overhead power lines in the 10 > kV range? > > Anyway, my point here is that the power line > cross at the overhead poles > won't just put 120V on the phone lines, but 10kV, > likely incinerating the > line. I'm not sure where the power line cross > test is simulating, but it's > not at the overhead poles. > > Besides that, most telephone wiring is buried. > > Just my 2C, > Sam > --- 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: AV terminations
I read in !emc-pstc that Colgan, Chris wrote (in ) about 'AV terminations' on Thu, 12 Dec 2002: >Correct for audio but video is usually 75ohms, input and output. Indeed; I didn't notice that the OP asked for video as well. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! --- 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: Location of CE DoCs - electronic copies
I read in !emc-pstc that Gregg Kervill wrote (in <004901c2a1ee$e45d66d0$7100a8c0@MENHADEN>) about 'Location of CE DoCs - electronic copies' on Thu, 12 Dec 2002: >There is a problem with "..the reader is guaranteed to get the latest >revision as stored in our Document Control system." > >The latest drawing has NO RELEVANCE WHATEVER to the CE Marking File. What we >are required to record is the "As Built Standard" of the product tested - in >terms of its Safety or EMC performance. > >It is for precisely this reason that UL/CSA/et al use specially written >Product Descriptions to allow manufacturing follow-up inspection. > >Evaluation for safety (and EMC) relates to ONE PRODUCT (the type-test model) >- if current production standard deviates significantly (in safety or emc >terms) from that original type-test model then re-evaluation is required to >limit potential corporate liability. This is an exceedingly stringent and impracticable interpretation. Of course, engineering changes are not prohibited, which is what seems to be implied. Due diligence can be demonstrated if each change is evaluated by a competent person to *determine* whether re-testing (which can be limited re-testing) is required or not. This is precisely the purpose of keeping the technical file, which should record all such evaluations -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! --- 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"
EMCD + RTTED - OJEC publication consolidated list of harmonised standards
Hello all, New lists of harmonised standard for EMC directive and R&TTE directive was published on 7th December, can be found at: http://europa.eu.int/eur-lex/en/oj/2002/c_30420021207en.html Best regards Helge Knudsen Test & Approval manager Niros Telecommunication Hirsemarken 5 DK-3520 Farum Denmark Tel +45 44 34 22 51 Fax +45 44 99 28 08 email h.knud...@niros.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...@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: TNV Test Generator
You're welcome, John. Yes, the test seems brutal. In North America, ringing is maximum 105Vrms, possibly riding on up to a -56.5Vdc wetted line (but not necessarily) and is limited to a few tens of mA. 120V/1200Ohms is still only 100mA, but that doesn't mean it won't cause grief at 3-5 times the US ringing current. However, the specification is for that source, IF there isn't one available to simulate the actual network. Sort of a poor man's networks simulator. Regards, Peter L. Tarver, PE Product Safety Manager Sanmina-SCI Homologation Services 2000 Ringwood Ave. San Jose, CA 95131-1749 V: 408-904-2081 F: 408-904-2095 M: 408-234-3529 peter.tar...@sanmina-sci.com > From: John Allen > Sent: Thursday, December 12, 2002 8:18 AM > > Peter > > Thanks for that - quite a different background to > how it seemed to read to > me! > > But in that case it does seem a bit of a "brutal" > test to apply to guard > against a hazard caused solely by a > telecomms-circuit source - surely a > relatively low power source would be appropriate? > > Any idea why they did not more closely specify > the equipment to be used? > > Regards > > Johh Allen > --- 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"
