Re: Ferrites for GND
Hi Dan. Two ferrite manufacturers I use are Stewart and Fair-Rite. Both of them have catalogs containing great detail graphs of performance of their various materials. Some of the 43 and 44 ferrite materials have very good low frequency performance. I would suggest, because I have no further details, that you contact their respective engineers as to what materials, form factors, and other considerations would work best. Warren Birmingham Epsilon-Mu Consultants (510) 793-4806 email: war...@epsilon-mu.com website: http://www.epsilon-mu.com On Friday, Oct 11, 2002, at 12:01 US/Pacific, Dan Pierce wrote: I have always been reluctant to place ferrite beads in the ground path, but I see them frequently in reference designs for USB and Analog Audio. What kind material should this be and what characteristics would this type of ferrite have. I am assuming this ferrite would not have 600 Ohm impedance @ 100MHz Thanks in advance, Daniel J. Pierce Sr. Design Engineer OpenGlobe, Inc. (An Escient Technologies Affiliate) 6325 Digital Way Indianapolis, IN 46278 mailto:dpie...@openglobe.net P: (317) 616.6587 F: (317) 616.6587 --- 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: grounding schemes & EMI
David,
Telecom ("Bellcore") usage is to keep signal, surge and power currents off
chassis and safety grounds. This is understandable. It is due not only to
audio sensitivity, but to the need to protect equipment from substantial
peak (hundred of amps) surges at fairly high (thousands of volts) peak
voltage.
Practically speaking, if you isolate a ground, you must isolate all the
signal and return conductors referenced to it as well. It requires good
balance in signal and return conductors, and measures to sure that balance
is not disturbed. This takes meticulous design, and some expense in
manufacturing. I have seen this done with signals in the hundreds of MHz,
but care had to be taken in layout, connector and cable selection and
construction.
Surge protector current must be routed away from signal return current. If
the chassis of a device is connected to the surge return path, a surge on
metallic conductors will be present on the chassis of the protected device.
This may be of little consequence to the device, where all grounds and Vcc
rise to the surge potential at once. But if it connects to another
equipment whose chassis ground is different, a sizable potential can appear
between signal conductors from the surged device and client equipment not
sharing its ground. That is not a good thing!
At sufficiently high frequencies there is no "ground" at all, really, only
return paths of various shapes, lengths and impedance. We can then make the
argument that - as long as we don't have to deal with surge currents -- our
chassis and digital grounds be tied together. This simplifies shielding.
But we still have to deal with surge somehow, and now, I suggest, we can
say that the SURGE return should be isolated, not the digital ground.
Higher frequency ESD transients are more problematic. Grounding
circuit-pack faceplates only at the bottom is NOT helpful! Connecting them
to the board ground is BAD. Before being laid off, I was slowly converting
people to the idea that ESD currents need to be treated as UHF radio
energy, and shields constructed accordingly; faceplates with 360 degree
grounds to the chassis. In some cases, it is enough to provide paths to the
chassis before such currents can flow onto the board, but induced fields
are often troublesome. For sure, ESD must NOT be allowed into circuit pack
Vcc and ground. An ESD trace or guard band is often used, but this can be
unnecessary -- why parallel a metal panel with a trace? -- or insufficient;
a guard band NOT connected to chassis, as when a card is being inserted,
may actually couple an ESD event to places where it can do harm. Anyway,
when it IS inserted, you can't reach it, so why have it? And a trace
leading ESD to the backplane puts it exactly -- among all the nice clean
signals -- where you do NOT want it! (I've also seen an encircling trace
resonate and cause EMC problems.)
My approach is very simple: Where will current go, and what will it do?
If you use this approach, you will find others coming over to your point of
view, especially when you are once in a while spectacularly right.
Cortland
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Re: LED's and laser safety?
Gary, I was recently in conversation with UL about LEDs whereas I am now being told that UL has convinced the European counterparts that LEDs are no longer considered Class I Lasers and the requirements for them to be tested as such has been dropped. UL no longer treats them that way in their CB Reports. Warren Birmingham Epsilon-Mu Consultants (510) 793-4806 email: war...@epsilon-mu.com website: http://www.epsilon-mu.com On Thursday, Oct 10, 2002, at 08:53 US/Pacific, Gary McInturff wrote: IEC-825 has incorporated LED's into the safety standard but, from what I can tell, left a great deal of confusion. I typically deal with the 5 - 10 mcd devices and haven't been required to provide any IEC-825 conformity proof for the Western European test house. We may be jumping up to about 60 mcd and non-focused devices and I don't know where the standard starts to become concerned. I hate to buy the standard if it doesn't provide any clarity for these types of parts. Could you folks clue me in? Gary --- 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: grounding schemes & EMI
A good way to think about this, especially on a larger size board, is to imagine a transmission line resonator. Assume for the moment that the shielding enclosure and the board ground are tied together at one point. In this case, the board will go resonant when the length of the board ground measured from the tie point becomes 1/4 of a wavelenth. This is not that long of a distance at even a low order harmonics of 100 MHz. All kinds of nasty things happen with such a resonance, the worst being radiated/conducted emissions, though circuit operation of sensitive nodes can be affected as well. Don Borowski Schweitzer Engineering Labs Pullman, WA David Heald on 10/11/2002 12:53:27 PM Please respond to David Heald To: "'emc-p...@majordomo.ieee.org'" cc:(bcc: Don Borowski/SEL) Subject: grounding schemes & EMI All, I'm trying to convince a few people here that completely separating the digital and chassis grounding on our product is not always the best way to go. Unfortunately, a lot of the people I'm dealing with are ex Bellcore engineers who worked a lot with isolated grounds and are convinced that isolated grounds are the only way to go. Now we're dealing with optical interfaces and speeds well in excess of 100MHz, so I really want to see the grounds tied together as much as possible. While I know that combining the digital and chassis grounds is for the most part better once you get above a few hundred MHz, putting together concrete arguments is proving to be a bit elusive. I luckily have some high level backing that will let me push my views, but I am one person up against a team of industry vets. If anyone has been in this boat before and won, could you share some of the tactics or arguments that you used? I know this issue has been discussed in the past, but a fresh discussion of the relative benefits of isolating the D and Cgnds would probably be beneficial to the group as well. See below for my views on the issue. Thanks Dave My views for telecom equipment with a backplane and plug in circuit packs (and a good tight chassis around it all): (Note that Analog grounds are outside of the scope of this statement - I'm focusing on Digital grounds and Chassis ground) The benefits of separating Dgnd and Cgnd have to do with defining your signal impedances and SI in general. When you place this system inside a Cgnd "balloon", all should be well but maybe there is some extra noise due to RF being trapped within the balloon. However, if the Cgnd and Dgnd are tied together throughout the system, the effect should be similar to "heat shrinking" your conductive chassis Cgnd ballon onto your Dgnd. The single ended signal return currents should still follow their original paths and things should essentially remain unchanged. I could see some possibility (I'll avoid use of the word potential here :o) ) for RF currents on the circuit pack card grounds due to RF fields contained within the faraday cage, but I think these could be mitigated by clever bonding of the grounds on circuit packs. I think that isolating the faceplate from the Dgnd on the circuit packs but stitching the bottom edge (faceplate to backplane) Cgnd ESD guard band to Dgnd could alleviate stray currents on the cards and keep them relatively clean - all while still maintaining the bonding of the Cgnd and Dgnd on a system level. The idea (as my brain developed it) is to keep the stray currents at the periphery of the card by limiting the through connections on the circuit packs and forcing stray currents to flow near the edge of the card. The backplane should for the most part have Dgnd and Cgnd be one and the same. Does this raise any red flags for anyone? I'm expecting at least a few, but this is the best scheme that I can come up with right now. --- 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 e-mail may contain SEL confidential information. The opinions expressed are not necessarily those of SEL. Any unauthorized disclosure, distribution or other use is prohibited. If you received this e-mail in error, please notify the sender, permanently delete it, and destroy any printout. Thank you. --- This message is from the IEEE EMC Society Product Safe
RE: Twisting the LVD (was: RE: CE Mark vs. e-Mark)
Thanks everyone. We do indeed want to use the LVD anyway, and have adopted the interpretation for years that has now been made official by the guideline quoted below. Jim Eichner, P.Eng. Regulatory Compliance Manager Xantrex Technology Inc. e-mail: jim.eich...@xantrex.com web: www.xantrex.com Any opinions expressed are those of my invisible friend, who really exists. Honest. No really. Confidentiality Notice: This email message, including any attachments, is for the sole use of the intended recipient(s) and may contain confidential and privileged information. Any unauthorized review, use, disclosure or distribution is prohibited. If you are not the intended recipient, please contact the sender by reply e-mail and destroy all copies of the original message. -Original Message- From: John Allen [mailto:john.al...@era.co.uk] Sent: Wednesday, October 09, 2002 10:25 AM To: 'Peter L. Tarver'; emc-p...@majordomo.ieee.org Subject: RE: Twisting the LVD (was: RE: CE Mark vs. e-Mark) Peter I think that your question is answered quite clearly in the second paragraph that I quoted from the guidelines, where it states: 'Following discussions with Member States the Commission has taken the position that the term "designed for use with a voltage range" shall be understood at equipment having either a rated input voltage or a rated output voltage inside this voltage range.' Therefore the 12V to 120V (or 230V for Europe) device described in your example is quite clearly within the scope of the LVD - and, Yes, similar devices are available in Europe. For example, see the illustration of a similar device for sale on the RS Components Website in the UK at http://rswww.com/cgi-bin/bv/browse/Module.jsp?BV_SessionID=1646810601.10 34183756&BV_EngineID=ccchadcghdjlhhmcfngcfkmdgkldfhk.0&stockNo=597475&lo gText=uk520&logType=103&prmstocknum=597475&logText=uk520&logType=103 This has a UK BS1363 13A socket and carries a CE Mark - but under what Directive, or Directives, I do not know as I do not have the DoC. In fact it might well include the EMC Directive as it could be used outside of a vehicle and directly from a 12V automobile battery (a good way to run your central heating timer and boiler controls when there is a mains power cut!) The aim of the LVD is to ensure protection of persons (and domestic animals!), and the shock and fire hazards from such a device are just at least as high as a unit where the equipment is supplied at 230V and has a 230V convenience outlet - so application of the LVD (and possibly the EMCD) is entirely appropriate. Regards John Allen Technical Consultant Electromagnetics, Safety and Reliability Group ERA Technology Ltd Cleeve Rd Leatherhead Surrey KT22 7SA Tel:+44 (0) 1372-367025 (Direct) +44 (0) 1372-367000 (Switchboard) Fax:+44 (0) 1372-367102 (Fax) -Original Message- From: Peter L. Tarver [mailto:peter.tar...@sanmina-sci.com] Sent: 09 October 2002 15:50 To: emc-p...@majordomo.ieee.org Subject: Twisting the LVD (was: RE: CE Mark vs. e-Mark) John - The case of internal use of elevated voltages (as in a lap top computer screen backlight) is clearly addressed by the interpretation. To test the consistency of the interpretation, imagine a product with a supply voltage below the limits in the LVD, where the LVD would not apply to that product. That product then performs power transformation (or conversion) and, in turn, supplies other equipment (whether ancillary to the equipment performing the conversion or not) at voltages within the scope of the LVD, making the LVD applicable to the latter product. Does the term "supply" in reference to the aforementioned interpretation apply only to the energy sinking port of equipment or to all equipment ports, whether sinking or sourcing electrical energy? Example: A product available in the US (and possibly in Europe) is a power inverter that can supply household appliances using an automobile battery as its source. Handy for weekend campers that prefer to bring a few conveniences along with them. Regards, Peter L. Tarver, PE Product Safety Manager Sanmina-SCI Homologation Services San Jose, CA peter.tar...@sanmina-sci.com > -Original Message- > From: John Woodgate > Sent: Wednesday, October 09, 2002 12:37 AM > To: emc-p...@majordomo.ieee.org > Subject: Re: CE Mark vs. e-Mark > > Although the wording of the LVD implies that > the voltage limits > apply to internally-generated voltages, there is > now an official > 'interpretation' that they apply only to supply voltages. > -- > Regards, John Woodgate --- 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
grounding schemes & EMI
All, I'm trying to convince a few people here that completely separating the digital and chassis grounding on our product is not always the best way to go. Unfortunately, a lot of the people I'm dealing with are ex Bellcore engineers who worked a lot with isolated grounds and are convinced that isolated grounds are the only way to go. Now we're dealing with optical interfaces and speeds well in excess of 100MHz, so I really want to see the grounds tied together as much as possible. While I know that combining the digital and chassis grounds is for the most part better once you get above a few hundred MHz, putting together concrete arguments is proving to be a bit elusive. I luckily have some high level backing that will let me push my views, but I am one person up against a team of industry vets. If anyone has been in this boat before and won, could you share some of the tactics or arguments that you used? I know this issue has been discussed in the past, but a fresh discussion of the relative benefits of isolating the D and Cgnds would probably be beneficial to the group as well. See below for my views on the issue. Thanks Dave My views for telecom equipment with a backplane and plug in circuit packs (and a good tight chassis around it all): (Note that Analog grounds are outside of the scope of this statement - I'm focusing on Digital grounds and Chassis ground) The benefits of separating Dgnd and Cgnd have to do with defining your signal impedances and SI in general. When you place this system inside a Cgnd "balloon", all should be well but maybe there is some extra noise due to RF being trapped within the balloon. However, if the Cgnd and Dgnd are tied together throughout the system, the effect should be similar to "heat shrinking" your conductive chassis Cgnd ballon onto your Dgnd. The single ended signal return currents should still follow their original paths and things should essentially remain unchanged. I could see some possibility (I'll avoid use of the word potential here :o) ) for RF currents on the circuit pack card grounds due to RF fields contained within the faraday cage, but I think these could be mitigated by clever bonding of the grounds on circuit packs. I think that isolating the faceplate from the Dgnd on the circuit packs but stitching the bottom edge (faceplate to backplane) Cgnd ESD guard band to Dgnd could alleviate stray currents on the cards and keep them relatively clean - all while still maintaining the bonding of the Cgnd and Dgnd on a system level. The idea (as my brain developed it) is to keep the stray currents at the periphery of the card by limiting the through connections on the circuit packs and forcing stray currents to flow near the edge of the card. The backplane should for the most part have Dgnd and Cgnd be one and the same. Does this raise any red flags for anyone? I'm expecting at least a few, but this is the best scheme that I can come up with right now. --- 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"
Ferrites for GND
I have always been reluctant to place ferrite beads in the ground path, but I see them frequently in reference designs for USB and Analog Audio. What kind material should this be and what characteristics would this type of ferrite have. I am assuming this ferrite would not have 600 Ohm impedance @ 100MHz Thanks in advance, Daniel J. Pierce Sr. Design Engineer OpenGlobe, Inc. > (An Escient Technologies Affiliate) 6325 Digital Way Indianapolis, IN 46278 mailto:dpie...@openglobe.net P: (317) 616.6587 F: (317) 616.6587 <>
Ground potential differences
Greetings all, I have become involved in a discussion regarding potential ground voltage differences between opposite ends of long network lines in industrial locations. As I understand it these differences are the reason for some network types floating cable shields or connecting them through snubbing networks to chassis instead of connecting directly. In the past I have simply accepted this explanation however I am becoming less comfortable with just accepting it. Can someone provide me with or point me to where I can obtain information on this subject? I am interested to know what the actual magnitude of ground differences may be from one end of a plant to another as well as where the numbers come from. Have they been calculated or actually measured? If shields are connected directly to chassis at each node of a network will there be an effect of equalizing the ground levels through the network or will enough current flow to melt the shield of the cable? Thanks in advance for any replies. Jeff Bailey Compliance Engineering SST - A Division of Woodhead Canada Phone: (519) 725 5136 ext. 363 Fax: (519) 725 1515 email: jbai...@mysst.com Web: www.mysst.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: 160 Amp Triax
>-Original Message- >From: Ted Rook [mailto:t...@crestaudio.com] >Sent: Friday, October 11, 2002 7:04 AM >To: < >Subject: 160 Amp Triax > > > >maybe you could try the DOD, they probably have something like >this to feed the deep space antenna at Arecibo ;-) > >seriously now, I'm very curious to know the application, or >have we been missiled by a typo? > >Best Regards > >Ted Rook, Console Engineering, ext 4659 > >Please note our new location and phone numbers: > >Crest Audio Inc, 16-00 Pollitt Drive >Fair Lawn, NJ 07410 USA > >201 475 4600 telephone receptionist, 8.30 - 5 pm EST. >201 475 4659 direct line w/voice mail, 24 hrs. >201 475 4677 fax, 24 hrs. Ted: Having had a little chuckle about the implications of needing 160 Amp, 2000 V triax, I think we need to clarify the OP's requirements. I'm gonna stick out my neck a bit, but I don't think the OP was looking for an RF triax cable, where the usual application of putting DC power on the line (by using a bias tee and blocking capacitor) is to support a remote RF pre-amplifier. The humor for we RF guys is that the implied power being transferred is vastly higher than reasonable for a pre-amp. I think the OP meant that he was looking for a power cable that was built in a triaxial manner, and that the central core and the inner shield layer would have to carry the 160 Amps with a 2000 V potential. And, that the insulation between the inner shield and the outer shield also had to withstand 2000 V potential. He didn't say anything about the current capacity of the outer shield, nor anything about the quality of any external insulation. So what he wants is a power transmission line built in a specific manner, not an RF line that also will carry current. I don't think it's an off-the-shelf product, but it sure is possible to build. I wonder if twisted shielded pair would work just as well? Hmmm, two strands of # 1/0, with heavy insulation. That would end up maybe 2" OD. Ed Ed Price ed.pr...@cubic.com Electromagnetic Compatibility Lab Cubic Defense Systems San Diego, CA USA 858-505-2780 (Voice) 858-505-1583 (Fax) Military & Avionics EMC Is Our Specialty Shake-Bake-Shock - Metrology - Reliability Analysis --- 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: Newcomer to NEBS
Jim, Please check out www.nebs-faq.com for some basic information about NEBS. I created this site to answer some of the more common questions about NEBS. You can also check out an article I wrote for Evaluation Engineering "What Every Startup Needs to Know About NEBS" at http://www.evaluationengineering.com/archive/articles/0502emc.htm. Even if you're not a startup, this article provides some tips on getting through the process. Conformity magazine's October issue will feature an article I wrote "NEBS Certification - Design with the Customer in Mind" and should be out in the next week or so. I'd be more than happy to help you with any questions not addressed above, please call me at 512.695.5871 or email at d...@lorusso.com. Good luck and best regards, Dave Lorusso Lorusso Technologies, LLC "Your NEBS, Product Safety and EMC Solution" www.lorusso.com 512.695.5871 (phone) 512.233.2939 (fax) -Original Message- From: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of Jim Eichner Sent: Tuesday, October 08, 2002 7:46 PM To: 'EMC-PSTC - forum' Subject: Newcomer to NEBS I'm starting up the learning curve on NEBS compliance, and am looking for any web resources or articles that would have a management-level primer on the requirements. All I know is that it covers EMC, safety, and environmental, there are different levels (1, 2, and 3?), and different potential customers disagree on what level we need to have. We need to understand the basic differences between these levels, how much testing is involved for each level, and what the cost might be. Of course we are going to get our hands on the standard(s) and study them, but in the meantime a primer would be very useful. We would also consider seminars if there's something close by the Pacific northwest. Thanks, Jim Eichner, P.Eng. Regulatory Compliance Manager Xantrex Technology Inc. phone: (604) 422-2546 fax: (604) 420-1591 e-mail: jim.eich...@xantrex.com web: www.xantrex.com Confidentiality Notice: This email message, including any attachments, is for the sole use of the intended recipient(s) and may contain confidential and privileged information. Any unauthorized review, use, disclosure or distribution is prohibited. If you are not the intended recipient, please contact the sender by reply e-mail and destroy all copies of the original message. --- 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: David Sproul...UL creepage limits ;~)
Creepage distance has nothing to do with current within the context of the product safety standards. Creepage distance is the distance across the surface of an insulating material. The specific Creepage distance for any product safety application is based on: 1) Working Voltage, 2) Installation Category - defines where on the power grid the product gets power = this defines the maximum anticipated overvoltage that the product will be subjected from upstream switching surges and other transients that may. 3) Pollution degree - the amount of potentially conductive contaminants that could reduce the creepage distance. 4) The insulation material's resistance to tracking - designated by the CTI rating of the insulating material. Creepage distances are specified such that, if there is a breakdown due to a short term transient, we want the breakdown to occur through the clearance distance (air) rather than across the creepage distance (insulating surface). The rationale being that once the transient that caused the breakdown subsides, the clearance is replaced by new air = no permanent damage. However, if a breakdown occurs across a Creepage distance, it leaves a permanent carbon path which thereby reduces the voltage required for the next breakdown. And so on and so on until a fire hazard (heat in the carbon path) or shock hazard occurs (complete breakdown). This helps to explain why clearance distances are also based on Air Pressure (altitude) since it directly related to the insulating properties of air. Again, if there is a breakdown, we want the air (clearance) to break down before the insulation (creepage). I hope this helps. Bill Bisenius bi...@productsafet.com Educated Design & Development, Inc. (ED&D) 2200 Gateway Centre Blvd. Suite 215 Morrisville, NC 27560 919-469-9434 www.productsafet.com -Original Message- From: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org] On Behalf Of David Sproul Sent: Friday, October 11, 2002 8:06 AM To: Ted Rook Cc: EMC-PSTC Subject:RE: David Sproul...UL creepage limits ;~) Ted, thank you for your response. I do not claim to be an expert, but I cannot accept that creepage has anything to to with the current flowing in a circuit. Surely it is the voltage across the material and the CTI of that material which determines the likelihood of tracking across the material to take place. As for your car battery melting story, cars must be wired differently in the US than in the UK, because I have connected negative to negative and positive to positive on many occaisions, and never had anything anymore exciting happen than the second car starts. Best regards, David Sproul. -Original Message- From: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of Ted Rook Sent: 09 October 2002 15:28 To: < Subject: David Sproul...UL creepage limits ;~) This is because when you double the voltage the power is proportional to a quarter of the current squared. In America the 120V power is at lower voltage but the current is twice as much and so the creepage is twice as well. Very high voltage circuits hardly creep at all whereas low voltages creep the most. That is why you should never join the two negative terminals when you jump start a car, the car battery charging circuits have so much creepage they can melt the battery. I though everybody knew that... --- 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 li
RE: Creepage
David - These are not harmonized standards. UL 891 bases it's spacings on US electrical distribution standards, while EN60439-1 most likely relies on IEC60664. Regards, Peter L. Tarver, PE Product Safety Manager Sanmina-SCI Homologation Services San Jose, CA peter.tar...@sanmina-sci.com > -Original Message- > From: David Sproul > Sent: Friday, October 11, 2002 6:15 AM > > Sorry Brian, > I missed your response until now. The standards > I was using was EN 60439-1 > for Europe and UL 891 in America. These were the > standards recommended by > the customers association and UL. > > Best regards, > David Sproul. --- 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"
Relays in Over Temperature Protection Circuits
Greeting to all, Our company makes Laboratory Instrumentation which many employs a small furnace. In case the furnace control circuit fails, we have a secondary Over Temperature Protection Circuit (OTPC) which opens a double pole relay to shut power off to the heater coils. In a new design we are working on, the Relay in the OTPC only has an Open Contact dielectric strength rating of 1000VAC. Basic insulation according to EN61010-1 would be 1350VAC or 1900VDC. The relay does meet Reinforced insulation requirements between the contacts (primary mains 230VAC) and the Secondary Coil. Does this relay have to have an Open Contact dielectric rating that meets Basic Insulation requirements to be used in a OTPC circuit? Best regards, Brian Kunde LECO Corp. --- 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: ESD protection for test equipment
Doug, When I was developing network adapters at my previous company, we would use a long cable-- close to the maximum length specified-- between the equipment we were electrostatic discharge (ESD) testing and our support equipment. These long cables were wound on the reels that the cable came on, to give us some common-mode choke effect against ESD, electrical fast transient/burst (EFTB), and other surges during the immunity tests. (It also made it easier to haul them around.) We also reserved some hubs and host computers just for immunity testing, so that we wouldn't damage the good hosts/hubs we used for emissions testing. I usually reserved one of my prototypes for emissions testing, and a second for immunity tests. Now, testing products for clients, I usually get only one unit for the verification/certification tests. So I try to run emission tests first, followed by tests that have a low chance of damaging the product (harmonics, flicker, radiated immunity, conducted immunity, magnetic field immunity, voltage dips), and finish up with tests that have a high probability of damaging the product (EFT/B, surge, ESD). John Barnes KS4GL dBi Corporation http://www.dbicorporation.com/ mail2web - Check your email from the web at http://mail2web.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: requirement for surge and EFT
Hello George, EN 55024:1998, the title of Table 4 is "Immunity, input a.c. power ports (including equipment marketed with a separate a.c./d.c power converter)". The table includes surge and fast transients. Seems like this issue must have come up before. Hope this helps, Don Umbdenstock Tyco Safety Products -- Sensormatic > -- > From: George Stults[SMTP:george.stu...@watchguard.com] > Reply To: George Stults > Sent: Thursday, October 10, 2002 4:13 PM > To: 'emc-p...@ieee.org' > Subject: requirement for surge and EFT > > > Hello Group, > > I am talking with an offshore manufacturer who is suggesting that their CE > marked ITE gear does not have to pass Surge and EFT since it runs off > 12Vdc, > normally provided by an AC/DC power supply, which is supplied in the same > package. They suggest that the AC/DC power supply, but not the ITE, has > to > pass Surge, etc. I'm sure that the whole system has to pass, but I don't > know chapter and verse to quote. I suppose the scope should be spelled > out > in EN55024 but I don't have a copy of it, yet. > > Thanks in advance. > > George Stults > > --- > 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: requirement for surge and EFT
Regardless of what the standard says, and I believe it does apply to the equipment through the power supply, what are going to tell you customer when all you hard work in designing the product goes out the window after the supply allows the system to be brought down. Hey, it cost me $300 over the product line and its the power supply vendor's fault! Want to buy even more equipment from me that will fail? However, it is the manufacturer who has all of the financial responsibilities and if he determines, rightly or wrongly, that it doesn't apply. Warn him, skip the test and move on. Your test report will simply not reflect the test - without comment by the test house - and when push comes to shove he's swinging in the wind by himself. Gary -Original Message- From: Chris Maxwell [mailto:chris.maxw...@nettest.com] Sent: Friday, October 11, 2002 5:03 AM To: am...@westin-emission.no; emc-p...@ieee.org Subject: RE: requirement for surge and EFT Actually, I don't even know if you need to read a standard for this one...just think about it for a second and apply some common sense. So the power supply has passed EFT and Surge. That's great. What was the criteria for susceptability? Many standards allow Criterion B performance (upset during the test with self recovery after). So, if they tested to Criterion B performance, the power supply could put out 0 Volts during a Surge and then self recover after the Surge. When the power supply manufacturer performed their testing, did they test to performance Criterion A (performance within specified limits). If so, did they actually put an oscilloscope on thier output and measure how much of the Surge or EFT passes through as ripple? If not, then how can you predict how a product using this power supply will react? Using a compliant supply is a great first step toward compliance. However, it probably doesn't preclude from system testing unless the power supply manufacturer completely characterized their outputs during their testing. For example, if their test data states that they passed Surge and EFT while only passing on 30mV of ripple and no transients; and if you know that your inputs can withstand 30mV of ripple and no transients; then you could claim "due diligence" and not test. If the power supply manufacturer didn't test to Criterion A with detailed record keeping; then how could you trust the overall system without testing? 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 | > -Original Message- > From: am...@westin-emission.no [SMTP:am...@westin-emission.no] > Sent: Friday, October 11, 2002 3:49 AM > To: emc-p...@ieee.org > Subject: Re: requirement for surge and EFT > > > I do not have a copy of EN55024. > But from IEC 61000-6-1:1997 " Electromagnetic compatibility (EMC)> -> Part > 6-1: > Generic standards > -> Immunity for residential, > commercial and light-industrial environments", page 23 - Immunity DC input > /output power ports- Note 4 Burst / Surge, I quote: > "Not applicable to input ports intended for connection to a battery or a > rechargeable battery which must be removed or disconnected from the > apparatus for recharging. Apparatus with DC power input port intended for > use with an AC/DC power adaptor shall be tested on the AC power input of the > AC/DC power adaptor specified by the manufacturer or, where none is so > specified, using a typical AD/DC adaptor. The test is applicable to DC power > input ports intended to be connected permanently to cables longer than 10m". > > So, the complete system shall be burst & surge tested according to IEC > 61000-6-1:1997. > > Amund > > > > -Opprinnelig melding- > > Fra: owner-emc-p...@majordomo.ieee.org > > [mailto:owner-emc-p...@majordomo.ieee.org]På vegne av George Stults > > Sendt: 10. oktober 2002 22:13 > > Til: 'emc-p...@ieee.org' > > Emne: requirement for surge and EFT > > > > > > > > Hello Group, > > > > I am talking with an offshore manufacturer who is suggesting that their CE > > marked ITE gear does not have to pass Surge and EFT since it runs > > off 12Vdc, > > normally provided by an AC/DC power supply, which is supplied in the same > > package. They suggest that the AC/DC power supply, but not the > > ITE, has to > > pass Surge, etc. I'm sure that the whole system has to pass, but I don't > > know chapter and verse to quote. I suppose the scope should be > > spelled out > > in EN55024 but I don't have a copy of it, yet. > > > > Thanks in advance. > > > > George Stults > > > > --- > > 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
160 Amp Triax
maybe you could try the DOD, they probably have something like this to feed the deep space antenna at Arecibo ;-) seriously now, I'm very curious to know the application, or have we been missiled by a typo? Best Regards Ted Rook, Console Engineering, ext 4659 Please note our new location and phone numbers: Crest Audio Inc, 16-00 Pollitt Drive Fair Lawn, NJ 07410 USA 201 475 4600 telephone receptionist, 8.30 - 5 pm EST. 201 475 4659 direct line w/voice mail, 24 hrs. 201 475 4677 fax, 24 hrs. --- 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: Newcomer to NEBS
In addition to the new GR-63 that came out (and there are already clarifications supplied by Telcordia, based on industry queries - call Rich Kluge), Telcordia is now amending GR-1089 (November time frame) with some drastic changes: 1. Ferrites are being banned from cables leaving the test chamber during radiated emissions/immunity (filters allowed) 2. EFT added Read the standards (the conference was good as a primer), talk to a competent lab and prepare $$$: NEBS is not a cheap proposition. The photos shown by Verizon about the fate of 140 West St CO (that stood next to #7 WTC building) shows the importance of NEBS to such a disaster. Regards, Naftali Shani, Catena Networks (www.catena.com) 307 Legget Drive, Ottawa, Ontario, Canada K2K 3C8 613.599.6430/866.2CATENA (X.8277); C 295.7042; F 599.0445 E-mail: nsh...@catena.com -Original Message- From: Garry Hojan [mailto:gho...@regulatory-compliance.com] Sent: Wednesday, October 09, 2002 11:04 PM To: Gary McInturff; Jim Eichner; EMC-PSTC - forum Subject:RE: Newcomer to NEBS Hi Jim, In addition to looking for a competent test house, if you are going to be dealing with Verizon, make sure that the test house is approved by Verizon as an ITL. Their *Verizon's* requirements, from both a scrutiny and monetary standpoint, have unfortunately reduced the number of choices you will have. Also, it is always recommended to have the blessing of the test plans by the RBOCs prior to going through the entire process (it always amazes me that this is rarely done). This can and will reduce your post test headaches. Just another 2 cents. Best regards, Garry Hojan www.regulatory-compliance.com Watch for our soon to be released "NEW and IMPROVED" website. -Original Message- From: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of Gary McInturff Sent: Wednesday, October 09, 2002 7:36 AM To: Jim Eichner; EMC-PSTC - forum Subject: RE: Newcomer to NEBS Seems simple enough request but for every reference I'm going to give you someone will point out that some RBOC or other has different requirements, and they will be quite correct. In fact AT & T actually calls its documents NEDS not NEBS. The NEBS conference is going on this week and a new issue of GR-63 is coming out, but Verizon has already said they would reject it. This is typical of the process so be prepared to deal with it. The is a document SR-3580 Network Equipment-Building System (NEBS) Criteria Levels A Module of NEBSFR, FR-2063. That theoretically defines these requirements - but Verizon objects to them and places their own requirements on the different classifications for class 1 through 3. The other RBOCS have some heartburn with it as well, but it may at least be a starting point. Very basically there are really only two practical types for switch and routing equipment. Level 1 for co-locations inside RBOC facilities where the RBOCs are required to provide space and power to competitors. and level 3 for Central office locations - (the RBOCs themselves own the equipment). Next you have to worry about earthquake ratings etc, zones 1 through 4. No really much sense, in my opinion, of doing anything less than level 4. The RBOC's have pretty large areas of operation and they all have zone 4 areas. So unless you are planning on restricting where you equipment goes you'll need to go to level 4. You're going to have to sit down with the standards and a good test house to get this all straight Jim, and then you'll only be close. You have to deal with NEBS (Purchase the FR-2063 CD referenced about and it contains GR-63, GR-1089 the SR-3580 document and GR-78 - grab a beer a do some light reading, and then discuss deviations with a good test house. There are slight differences for SBC, AT &T, and Verizon just wonders around on their own. Verizon has it requirements on its website, as does AT&T 802-010-100 but you'll have to dig around on their web site as I don't have the URL's at the moment. Gary -Original Message- From: Jim Eichner [mailto:jim.eich...@xantrex.com] Sent: Tuesday, October 08, 2002 5:46 PM To: 'EMC-PSTC - forum' Subject: Newcomer to NEBS I'm starting up the learning curve on NEBS compliance, and am looking for any web resources or articles that would have a management-level primer on the requirements. All I know is that it covers EMC, safety, and environmental, there are different levels (1, 2, and 3?), and different potential customers disagree on what level we need to have. We need to understand the basic differences between these levels, how much testing is involved for each level, and what the cost might be. Of course we are going to get our hands on the standard(s) and study them, but in the meantime a primer would be very useful. We would also consider seminars if there's something close by the Pacific northwest. Thanks, Jim Eichner, P.Eng. Regu
RE: Creepage
Sorry Brian, I missed your response until now. The standards I was using was EN 60439-1 for Europe and UL 891 in America. These were the standards recommended by the customers association and UL. Best regards, David Sproul. -Original Message- From: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of Brian O'Connell Sent: 08 October 2002 17:57 To: emc-p...@majordomo.ieee.org Subject: RE: Creepage At least for UL60950 (3d ed) and Ul 3101-1/3111-1, the spacing tables are the same as EN60950:2k and EN 610101-1. What UL standards have spacing requirements that are different than the EN std w/equivalent scope? I would really appreciate this info. thanks, Brian -Original Message- From: David Sproul [mailto:david.spr...@alexanderlynn.co.uk] Sent: Tuesday, October 08, 2002 8:51 AM To: richwo...@tycoint.com Cc: EMC-PSTC Subject: RE: Creepage Can anyone give a rational reason why UL ask for around twice the creepage distances for 120V that EN standards ask for 230V. I realise this is a bit vague, but I can dig out some examples if any needs to be convinced. I have been asked this by customers on a number of occasions, and have always meant to find out so I would no longer have to apologise for not knowing. --- 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: requirement for surge and EFT
George, the product has to comply with the standards. In this particular case, the product consists of two parts that operate together, and must therefore be tested as a system. All of the power line tests apply when the when the complete system is powered and operating. Richard Woods Sensormatic Electronics Tyco International -Original Message- From: George Stults [mailto:george.stu...@watchguard.com] Sent: Thursday, October 10, 2002 4:13 PM To: 'emc-p...@ieee.org' Subject: requirement for surge and EFT Hello Group, I am talking with an offshore manufacturer who is suggesting that their CE marked ITE gear does not have to pass Surge and EFT since it runs off 12Vdc, normally provided by an AC/DC power supply, which is supplied in the same package. They suggest that the AC/DC power supply, but not the ITE, has to pass Surge, etc. I'm sure that the whole system has to pass, but I don't know chapter and verse to quote. I suppose the scope should be spelled out in EN55024 but I don't have a copy of it, yet. Thanks in advance. George Stults --- 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: David Sproul...UL creepage limits ;~)
Ted, thank you for your response. I do not claim to be an expert, but I cannot accept that creepage has anything to to with the current flowing in a circuit. Surely it is the voltage across the material and the CTI of that material which determines the likelihood of tracking across the material to take place. As for your car battery melting story, cars must be wired differently in the US than in the UK, because I have connected negative to negative and positive to positive on many occaisions, and never had anything anymore exciting happen than the second car starts. Best regards, David Sproul. -Original Message- From: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of Ted Rook Sent: 09 October 2002 15:28 To: < Subject: David Sproul...UL creepage limits ;~) This is because when you double the voltage the power is proportional to a quarter of the current squared. In America the 120V power is at lower voltage but the current is twice as much and so the creepage is twice as well. Very high voltage circuits hardly creep at all whereas low voltages creep the most. That is why you should never join the two negative terminals when you jump start a car, the car battery charging circuits have so much creepage they can melt the battery. I though everybody knew that... --- 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: requirement for surge and EFT
Actually, I don't even know if you need to read a standard for this one...just think about it for a second and apply some common sense. So the power supply has passed EFT and Surge. That's great. What was the criteria for susceptability? Many standards allow Criterion B performance (upset during the test with self recovery after). So, if they tested to Criterion B performance, the power supply could put out 0 Volts during a Surge and then self recover after the Surge. When the power supply manufacturer performed their testing, did they test to performance Criterion A (performance within specified limits). If so, did they actually put an oscilloscope on thier output and measure how much of the Surge or EFT passes through as ripple? If not, then how can you predict how a product using this power supply will react? Using a compliant supply is a great first step toward compliance. However, it probably doesn't preclude from system testing unless the power supply manufacturer completely characterized their outputs during their testing. For example, if their test data states that they passed Surge and EFT while only passing on 30mV of ripple and no transients; and if you know that your inputs can withstand 30mV of ripple and no transients; then you could claim "due diligence" and not test. If the power supply manufacturer didn't test to Criterion A with detailed record keeping; then how could you trust the overall system without testing? 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 | > -Original Message- > From: am...@westin-emission.no [SMTP:am...@westin-emission.no] > Sent: Friday, October 11, 2002 3:49 AM > To: emc-p...@ieee.org > Subject: Re: requirement for surge and EFT > > > I do not have a copy of EN55024. > But from IEC 61000-6-1:1997 " Electromagnetic compatibility (EMC)> -> Part > 6-1: > Generic standards > -> Immunity for residential, > commercial and light-industrial environments", page 23 - Immunity DC input > /output power ports- Note 4 Burst / Surge, I quote: > "Not applicable to input ports intended for connection to a battery or a > rechargeable battery which must be removed or disconnected from the > apparatus for recharging. Apparatus with DC power input port intended for > use with an AC/DC power adaptor shall be tested on the AC power input of the > AC/DC power adaptor specified by the manufacturer or, where none is so > specified, using a typical AD/DC adaptor. The test is applicable to DC power > input ports intended to be connected permanently to cables longer than 10m". > > So, the complete system shall be burst & surge tested according to IEC > 61000-6-1:1997. > > Amund > > > > -Opprinnelig melding- > > Fra: owner-emc-p...@majordomo.ieee.org > > [mailto:owner-emc-p...@majordomo.ieee.org]På vegne av George Stults > > Sendt: 10. oktober 2002 22:13 > > Til: 'emc-p...@ieee.org' > > Emne: requirement for surge and EFT > > > > > > > > Hello Group, > > > > I am talking with an offshore manufacturer who is suggesting that their CE > > marked ITE gear does not have to pass Surge and EFT since it runs > > off 12Vdc, > > normally provided by an AC/DC power supply, which is supplied in the same > > package. They suggest that the AC/DC power supply, but not the > > ITE, has to > > pass Surge, etc. I'm sure that the whole system has to pass, but I don't > > know chapter and verse to quote. I suppose the scope should be > > spelled out > > in EN55024 but I don't have a copy of it, yet. > > > > Thanks in advance. > > > > George Stults > > > > --- > > 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
RE: Record retention
Hi Folks Also take into consideration the requirements of the Product Liability Directive which can effectively increase the 10 yr figure to a practical number of around 13 yrs, and the US product liability legislation which can be effectively unlimited in many cases. Regards John Allen Technical Consultant Electromagnetics, Safety and Reliability Group ERA Technology Ltd Cleeve Rd Leatherhead Surrey KT22 7SA Tel:+44 (0) 1372-367025 (Direct) +44 (0) 1372-367000 (Switchboard) Fax:+44 (0) 1372-367102 (Fax) -Original Message- From: Neil Helsby [mailto:nei...@solid-state-logic.com] Sent: 11 October 2002 08:30 To: emc-p...@majordomo.ieee.org Subject: Record retention For EU, the requirement is specified in the various Directives. The period is 10 years but it is not only the DoC that must be retained but also the technical files. >From the LVD Annex IV section 2: "The manufacturer must establish the technical documentation .. must keep it in the Community territory at the disposal of the relevant national authorities for inspection purposes for a period ending at least 10 years after the last product has been manufactured." Note that the Directive goes on to say: "Where neither the manufacturer nor his authorized representative is established within the Community, this obligation is the responsibility of the person who places the electrical equipment on the Community market." Regards, Neil Helsby ** This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error please notify the system manager. This footnote also confirms that this email message has been swept by MIMEsweeper for the presence of computer viruses. www.mimesweeper.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 e-mail has been scanned for viruses by the WorldCom Internet Managed Scanning Service - powered by MessageLabs. For further information visit http://www.worldcom.com * Copyright ERA Technology Ltd. 2002. (www.era.co.uk). All rights reserved. The information supplied in this Commercial Communication should be treated in confidence. No liability whatsoever is accepted for any loss or damage suffered as a result of accessing this message or any attachments. _ This e-mail has been scanned for viruses by the WorldCom Internet Managed Scanning Service - powered by MessageLabs. For further information visit http://www.worldcom.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: requirement for surge and EFT
Something else to remember is that if the product has lines over 30m long or (for some product standards) which pass outside buildings, then these must also be surge tested. Burst testing on I/O leads is required if they are over 3m long. These tests may apply to the system as a whole. Thanks Ian Gordon -Original Message- From: am...@westin-emission.no [mailto:am...@westin-emission.no] Sent: 11 October 2002 08:49 To: emc-p...@ieee.org Subject: Re: requirement for surge and EFT I do not have a copy of EN55024. But from IEC 61000-6-1:1997 " Electromagnetic compatibility (EMC)-Part 6-1: Generic standards -Immunity for residential, commercial and light-industrial environments", page 23 - Immunity DC input /output power ports- Note 4 Burst / Surge, I quote: "Not applicable to input ports intended for connection to a battery or a rechargeable battery which must be removed or disconnected from the apparatus for recharging. Apparatus with DC power input port intended for use with an AC/DC power adaptor shall be tested on the AC power input of the AC/DC power adaptor specified by the manufacturer or, where none is so specified, using a typical AD/DC adaptor. The test is applicable to DC power input ports intended to be connected permanently to cables longer than 10m". So, the complete system shall be burst & surge tested according to IEC 61000-6-1:1997. Amund > -Opprinnelig melding- > Fra: owner-emc-p...@majordomo.ieee.org > [mailto:owner-emc-p...@majordomo.ieee.org]På vegne av George Stults > Sendt: 10. oktober 2002 22:13 > Til: 'emc-p...@ieee.org' > Emne: requirement for surge and EFT > > > > Hello Group, > > I am talking with an offshore manufacturer who is suggesting that their CE > marked ITE gear does not have to pass Surge and EFT since it runs > off 12Vdc, > normally provided by an AC/DC power supply, which is supplied in the same > package. They suggest that the AC/DC power supply, but not the > ITE, has to > pass Surge, etc. I'm sure that the whole system has to pass, but I don't > know chapter and verse to quote. I suppose the scope should be > spelled out > in EN55024 but I don't have a copy of it, yet. > > Thanks in advance. > > George Stults > > --- > 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" _ This e-mail has been scanned for viruses by the WorldCom Internet Managed Scanning Service - powered by MessageLabs. For further information visit http://www.worldcom.com _ This e-mail has been scanned for viruses by the WorldCom Internet Managed Scanning Service - powered by MessageLabs. For further information visit http://www.worldcom.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/
RE: requirement for surge and EFT
Hi George, I haven't got a copy of EN55024, but if it is anything like the format of EN61000-6-2, then the info you are looking for will appear as 'notes' under immunity testing of dc input and output ports will read ... "[EFTs & Surge] Not applicable to input ports intended for connection to a battery or a rechargeable battery which must be removed or disconnected from the apparatus for recharging. Apparatus with a d.c. power input port intended for use with an ac-dc power adaptor shall be tested on the a.c. power input of the ac-dc power adaptor specified by the manufacturer or, where none is specified, using a typical ac-dc power adaptor. The test is not applicable to d.c. power input ports intended to be permanently connected to cables less than 10m in length " This excerpt from BS EN 61000-6-2:1999 Table 3, Note 3. Not sure if EN55024 has similar statement. Regards - Chris Chileshe - Ultronics Ltd -Original Message- From: George Stults [SMTP:george.stu...@watchguard.com] Sent: Thursday, October 10, 2002 9:13 PM To: 'emc-p...@ieee.org' Subject:requirement for surge and EFT Hello Group, I am talking with an offshore manufacturer who is suggesting that their CE marked ITE gear does not have to pass Surge and EFT since it runs off 12Vdc, normally provided by an AC/DC power supply, which is supplied in the same package. They suggest that the AC/DC power supply, but not the ITE, has to pass Surge, etc. I'm sure that the whole system has to pass, but I don't know chapter and verse to quote. I suppose the scope should be spelled out in EN55024 but I don't have a copy of it, yet. Thanks in advance. George Stults --- 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 e-mail has been scanned for all viruses by Star Internet. The service is powered by MessageLabs. For more information on a proactive anti-virus service working around the clock, around the globe, visit: http://www.star.net.uk This e-mail has been scanned for all viruses by Star Internet. The service is powered by MessageLabs. For more information on a proactive anti-virus service working around the clock, around the globe, visit: http://www.star.net.uk --- 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: LED's and laser safety?
Folks, IEC 60825-1:2001 has an Annex G "Information to be provided by manufacturers of LEDs". This is an informative annex, the purpose for which is explained in the above title. I suggest that you start with asking your LED vendor to send you data in conformity with the above. If you're lucky you'll get some useful info. If you're unlucky you'll get "but IEC 60825-1 says it's for laser products" - tell such suppliers to go read the scope, which states "Throughout this part 1 light emitting diodes (LED) are included whenever the word "laser" is used." If enough users of LEDs ask their LED suppliers for Annex G data then eventually those suppliers will twig that this is an important marketing requirement so they had better start providing the info. Before anyone complains, yes it is known that the latest version of EN 60950-1 only cross-refers to the older version of 60825-1, but we're working to correct this in IEC TC108 (now responsible for IEC 60950-x). Reason? - difficulty of balancing revision dates within multiple standards - both revised documents were published the same year. It is therefore for users in this forum to satisfy themselves that an LED that is e.g. Class 1 per IEC 60825-1:2001 also meets the national implementations of IEC 60825-1 for the countries they wish to supply into. End of personal views... Regards, Richard Hughes -Original Message- From: Peter L. Tarver [mailto:peter.tar...@sanmina-sci.com] Sent: 10 October 2002 22:44 To: EMC-PSTC (E-mail) Subject: RE: LED's and laser safety? Gary - IEC60825-1 uses units of energy, energy/unit area, power and power/unit area (regardless of any "special" names associated with them) rather than candela or lumens, which are typical for simple LEDs. You'd need some formula to convert the units to those compatible with IEC60825-1. However, you might also want to look into IEC TS60825-6, Safety of Laser Products - Part 6: Safety of Products with Optical Sources, Exclusively Used for Visible Information Transmission to the Human Eye. A Technical Specification doesn't hold the same sway as a standard, but it is a useful reference for indicator LEDs. Regards, Peter L. Tarver, PE Product Safety Manager Sanmina-SCI Homologation Services San Jose, CA peter.tar...@sanmina-sci.com > -Original Message- > From: Gary McInturff > Sent: Thursday, October 10, 2002 8:53 AM > > IEC-825 has incorporated LED's into the > safety standard but, from what I can tell, left a > great deal of confusion. > I typically deal with the 5 - 10 mcd > devices and haven't been required to provide any > IEC-825 conformity proof for the Western European > test house. We may be jumping up to about 60 mcd > and non-focused devices and I don't know where > the standard starts to become concerned. I hate > to buy the standard if it doesn't provide any > clarity for these types of parts. > Could you folks clue me in? > Gary > --- 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: Testing for dry joints - Thank you
Thank you everyone for your very informed replies on the subject. 'Endurance' and 'use' does indeed involve vibration. The units are used on off-highway heavy duty vehicles and forklifts. The contacts are not gold-plated and I am glad I didn't make that clear because the info forthcoming (Thank you JW) is quite relevant to a second product I am working on. What is clear is that it is best to sort out the process. Saves one a lot of grief later on. Your replies have provided the much needed leverage to get process control to take responsibility. Best regards - Chris Chileshe - Ultronics Ltd This e-mail has been scanned for all viruses by Star Internet. The service is powered by MessageLabs. For more information on a proactive anti-virus service working around the clock, around the globe, visit: http://www.star.net.uk --- 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"
FW: Review of Telecommunications Customer Equipment Technical Reg ulat ion
A usefull document for those looking for some insight in regulatory approvals. Regards, Kris -Original Message- From: Antoniou, Christine [mailto:christine.anton...@aca.gov.au] Sent: vrijdag 11 oktober 2002 9:02 Subject: Review of Telecommunications Customer Equipment Technical Regulat ion Recognised Testing Authorities The ACA has released a discussion paper Review of Telecommunications Customer Equipment Technical Regulation. The ACA is seeking written submissions from members of the public, consumer groups, manufacturers, importers, test houses, retailers, carriers and service providers and other interested persons in response to the issues canvassed in the discussion paper. The ACA seeks your input to the attached paper. Also, feel free to forward this paper to others who may be interested in making comments. The closing date for submissions is 8 November 2002. If you have any questions about the issues discussed in the paper, please contact John Vardanega on (03) 9963 6915 or via email john.vardan...@aca.gov.au. The discussion paper is also available on the ACA website at www.aca.gov.au/labelling/telecom/techreview.htm. Regards Christine Antoniou Telecommunications Standards Team Australian Communications Authority Tel: (03) 9963 6814 Email: christine.anton...@aca.gov.au --- 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: requirement for surge and EFT
I do not have a copy of EN55024. But from IEC 61000-6-1:1997 " Electromagnetic compatibility (EMC)Part 6-1: Generic standards Immunity for residential, commercial and light-industrial environments", page 23 - Immunity DC input /output power ports- Note 4 Burst / Surge, I quote: "Not applicable to input ports intended for connection to a battery or a rechargeable battery which must be removed or disconnected from the apparatus for recharging. Apparatus with DC power input port intended for use with an AC/DC power adaptor shall be tested on the AC power input of the AC/DC power adaptor specified by the manufacturer or, where none is so specified, using a typical AD/DC adaptor. The test is applicable to DC power input ports intended to be connected permanently to cables longer than 10m". So, the complete system shall be burst & surge tested according to IEC 61000-6-1:1997. Amund > -Opprinnelig melding- > Fra: owner-emc-p...@majordomo.ieee.org > [mailto:owner-emc-p...@majordomo.ieee.org]På vegne av George Stults > Sendt: 10. oktober 2002 22:13 > Til: 'emc-p...@ieee.org' > Emne: requirement for surge and EFT > > > > Hello Group, > > I am talking with an offshore manufacturer who is suggesting that their CE > marked ITE gear does not have to pass Surge and EFT since it runs > off 12Vdc, > normally provided by an AC/DC power supply, which is supplied in the same > package. They suggest that the AC/DC power supply, but not the > ITE, has to > pass Surge, etc. I'm sure that the whole system has to pass, but I don't > know chapter and verse to quote. I suppose the scope should be > spelled out > in EN55024 but I don't have a copy of it, yet. > > Thanks in advance. > > George Stults > > --- > 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"
Record retention
For EU, the requirement is specified in the various Directives. The period is 10 years but it is not only the DoC that must be retained but also the technical files. >From the LVD Annex IV section 2: "The manufacturer must establish the technical documentation .. must keep it in the Community territory at the disposal of the relevant national authorities for inspection purposes for a period ending at least 10 years after the last product has been manufactured." Note that the Directive goes on to say: "Where neither the manufacturer nor his authorized representative is established within the Community, this obligation is the responsibility of the person who places the electrical equipment on the Community market." Regards, Neil Helsby ** This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error please notify the system manager. This footnote also confirms that this email message has been swept by MIMEsweeper for the presence of computer viruses. www.mimesweeper.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: Ethernet Radiated Emissions
> Pardon my naivety, but how does '100 Mbit' relate to frequencies of 30 and 60 kHz? Is this 100 Mbit per week? (;-) > -- > Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk First, a little background on auto negotiation. The IEEE 802.3u 100BaseTX auto negotiation specification uses a modified version of the link integrity test defined for 10BaseT devices. The link integrity test for 10BaseT devices uses the Normal Link Pulse (NLP), a burst pulse every 16 (+/- 8) microseconds. For 10/100 Mbps auto negotiation, a Fast Link Pulse (FLP) is used. The FLP includes the same NLP burst every 16 (+/- 8) msec for backward compatibility plus additional pulses every 62.5 (+/- 7) microseconds. The FLP burst generates code words that are used for compatibility exchanges (duplex settings) between link partners. If a device (such as an Ethernet switch) sends FLP, but only receives NLP from it's link partner (such as a server or workstation), it will stop sending FLP and enable standard 10BaseT operation. I suppose you can figure out that the frequency for 100 Mbps link pulses is 62.5 kHz. If not, calculate 1/16 us. Second, I recommend refraining from sarcastic comments in this forum, since that doesn't seem it was about naivety. I was actually trying to help. Best regards, Neven --- 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: High Voltage Equipment/Appliance Wire
>-Original Message- >From: John Woodgate [mailto:j...@jmwa.demon.co.uk] >Sent: Thursday, October 10, 2002 12:23 PM >To: emc-p...@majordomo.ieee.org >Subject: Re: High Voltage Equipment/Appliance Wire > > > >I read in !emc-pstc that POWELL, DOUG wrote (in >) about 'High Voltage >Equipment/Appliance Wire' on Thu, 10 Oct 2002: > >>I need to locate a resource for High Voltage Triax cable. It >should be >>rated to 2000V AC/DC on both the center conductor and the 1st >shield. The >>2nd shield will be grounded and then an overall jacket. In >addition it >>needs to be rated for 160 Amps continuous. > >This is for you esoteric hi-fi vinyl disc player tone arm? >-- >Regards, John Woodgate, OOO - Own Opinions Only. Yes; I believe he has an incredibly high-gain, liquid argon cooled, pick-up coil. Pressurized oil bearings are also giving him a problem. Ed Ed Price ed.pr...@cubic.com Electromagnetic Compatibility Lab Cubic Defense Systems San Diego, CA USA 858-505-2780 (Voice) 858-505-1583 (Fax) Military & Avionics EMC Is Our Specialty Shake-Bake-Shock - Metrology - Reliability Analysis --- 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"
