RE: Regulatory Compliance stifles innovation?
Hi Oscar: While I agree with you regarding Product Safety engineers in the field today, there is a group of System Safety engineers that have always (since 1962 when the concept began) taken the risk assessment and mitigation approach. I did not mean to suggest or imply that product safety engineers must learn and use risk assessment and mitigation. If the objective is to prevent injury, then we must first identify (in a product) the potential causes for injury. If a product employs voltages greater than, say, 30 volts, then the product has a potential to cause an electric shock type injury. This is NOT a risk assessment. Risk assessment is very difficult to define. Wikipedia is about the only source with a reasonably complete definition. (My System Safety handbook doesn't define risk assessment.) The Wikipedia defines risk assessment in terms of magnitude of the loss and the probability that the loss will occur. These are NOT criteria for prevention of injury. Rather, risk assessment assumes an injury will occur and addresses the means to reduce the probability of occurrence. The re-invention of safety engineering requires the engineer to identify the potential causes for injury that exist in a product. Today, we just don't think this way. Best regards, Rich ps: I do agree that product safety engineers and system safety engineers could indeed reduce the re-invention of the wheel! - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list.Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to emc-p...@ieee.org Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald:emc-p...@daveheald.com All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc __ This email has been scanned by the MessageLabs Email Security System. For more information please visit http://www.messagelabs.com/email __
RE: 4 wire resistance measurement lead set
_ From: Ken Javor [mailto:ken.ja...@emccompliance.com] Sent: Thursday, November 30, 2006 2:31 PM To: emc-p...@ieee.org Subject: Re: 4 wire resistance measurement lead set The old HP 4328A (I think there is a 4328B modern digital version) used a 1 kHz ac waveform and averaged the readings to zero out any galvanic potentials. Also it used very small potentials and currents so that it would not punch through any dielectric build-up or corrosion within the bond being measured. The latter property is important if you are measuring the surface conduction properties of a complex material. For EMI, as opposed to lightning or safety ground measurements, I think it was the best milliohmmeter ever made. Also consider the Keithley 580 Digital Microohmmeter. It has low-power dissipation in the unknown, selective DC or 1 kHz test current, 2-wire or Kelvin 4-wire, has a range of 2000 Ohms to 10 microohms and yields very stable readings. It's available used, and is the best microohmmeter ever made. (No conflict Ken; notice I said micro. g) Ed Price mailto:ed.pr...@cubic.com ed.pr...@cubic.com NARTE Certified EMC Engineer Technician Electromagnetic Compatibility Lab Cubic Defense Applications San Diego, CA USA 858-505-2780 (Voice) 858-505-1583 (FAX) Military Avionics EMC Is Our Specialty __ This email has been scanned by the MessageLabs Email Security System. For more information please visit http://www.messagelabs.com/email __ - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to emc-p...@ieee.org Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: emc-p...@daveheald.com All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: Regulatory Compliance stifles innovation?
Rich, It's the contrary one again... The standard you are quoting as problematic is IEC 60950-1. Going back into history, this standard was a derivation of IEC 950 which itself was created by combining two existing standards, IEC 380 and IEC 435. IEC 435 was derived from UL 478 and took an approach which I shall paraphrase as you never know what may go wrong, so don't spend too much time looking at fault conditions, just ensure that the enclosed parts aren't too flammable and, to be on the safe side, make sure the enclosure can reasonably contain any fire that may nevertheless start. Of course this is something of an oversimplification, but I think it adequate for this discussion. IEC 435 covered electronic data processing equipment which in those days meant rooms crammed full of large machines containing lots of printed circuit boards. I always seemed to me that IEC 380 was a derivation of VDE 0730 inc. Part 2P, though I never checked this and it's now probably too late. Anyway, it took the approach that you should perform enough fault tests to ensure that fire could not start in the first place. It consequently had much less stringent flammability requirements than IEC 435. IEC 380 covered office machines, such as photocopiers. This dualistic approach was incorporated into IEC 950 and was maintained in IEC 60950. I agree that IEC 60950-1 has become biased towards the preselection of plastic parts and don't have the standard to hand right now to quote the clause number, but if you look hard you should find it. Regards, Richard Hughes __ This email has been scanned by the MessageLabs Email Security System. For more information please visit http://www.messagelabs.com/email __ - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to emc-p...@ieee.org Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: emc-p...@daveheald.com All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: Regulatory Compliance stifles innovation?
Hi Rich, Well, you know me, I'm not so easy to convince! Safety standards (well, at least IEC 60950-1) have various constructional requirements to ensure that not only is the connection good when it leaves the factory gate, but it has a good chance of staying that way throughout the life of the product. I do not recall any such requirement in CISPR 22 or the like. Take earthing as an example, since it is important for both safety and EMC... IEC 60950-1 has a requirement that when you screw through an insulating material which could shrink in use (such as a pcb substrate) then you need to use a resilient washer to maintain contact pressure if the contact is relied on for protective earthing. Perhaps this is more particular to safety because the fault currents can be very high, but if one or more EMC contacts are not made then the emissions are likely to increase and the immunity decrease. IEC 60950-1 has requirements to limit the electropotential when using dissimilar metals. This reduces the likelihood of corrosion occurring during the life of the product. IEC 60950-1 has various requirements regarding the type of screw and associated construction (e.g. number of engaged turns) that can be used for providing a protective earth connection. This ensures the resulting mechanical joint has a certain degree of robustness. Of course these constructions are in the standard because they have been found to work over the years. You could presumably replace the resilient washer requirement with some sort of thermal cycling and ageing test; perhaps the electropotential requirement could be replaced by a salt spray test; and the other constructional requirements replaced by a combination of thermal-humidity cycling and vibration test. In this way you would have replaced requirements that are easy and cheap to incorporate and inspect to by expensive and lengthy tests. But if you do not incorporate the performance tests then you have just diminished safety in the longer term, even if the unit happens to pass the earth bond test during type examination. Regards, Richard Hughes __ This email has been scanned by the MessageLabs Email Security System. For more information please visit http://www.messagelabs.com/email __ - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to emc-p...@ieee.org Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: emc-p...@daveheald.com All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
RE: GR-1089 Issue 4 and Surge on Ethernet
Joe, The reason we (GR-1089 TTF) added the caveat regarding secondary protection to ground had to do with the possibility of longitudinal to metallic conversions as a result of asymmetric firing that would be synonymous with the firing of a primary protector. Protectors on the chip side of an isolation transformer will not do this conversion, thus performing a metallic surge on an Ethernet port would result in current flow paths that would not exist in the real world. In the real world if a transient is induced into the cable, the voltage would be the same on all conductors and there would be no current flow through the windings of the Ethernet isolation transformer regardless of what paths to ground exist on the chip side. So basically the exemption was a practical way to eliminate a test that added no value. It also reduces cost to the industry by eliminating the need for an expensive and un-necessary component to protect an 10/100 baseT Ethernet port. There were also concerns with GigE interfaces and the ability to protect them from metallic surges with commercially available devices and still meet performance criteria. So we felt the exemption was a positive and reasonable way of addressing the issue. As far as 4.6.9.1.1, I received the exact same question from a test lab yesterday. Here is essentially the same text I sent the lab. Dear XYZ LAB, The two conditions you mention below only apply to Ethernet interfaces with regard to metallic surges. Longitudinal surges on Ethernet ports always apply, unless exempted by one of the 3 bullets at the beginning of 4.6.9. As far as protection to ground, components on the IC side of the transformer that connect to ground do not cause the metallic exemption to be lost as the transformer provides isolation from a longitudinal to metallic conversion. If the TVS components that are grounded are on the surged side of the transformer, the metallic surges are not exempt. 4.6.9.1.1 applies to all products with any kind of secondary voltage protection. However, as with the rest of section 4, the intent of secondary protection relates to those components on the exposed side of an isolation transformer, not the chip side. For example interfaces with 65, 140, 200 or 270V sidactors/thyristors or Semtech LC-03 devices that are grounded that are on the surged side of the transformer need to be tested per 4.6.9.1.1. Generally protection on the IC side is about 5V and even with ADSLx is usually less than 20V and they are clamping devices. As a result there isn't really much if any value in trying to remove these and doing a surge on the exposed side at 5-20V, the energy is simply too low and is a waste of time. The IC's get as much or more energy from the full surge. Hopefully this answers your question. Jim Jim Wiese NEBS Project Manager/Senior Compliance Engineer ADTRAN, Inc. 901 Explorer Blvd. Huntsville, AL 35806 256-963-8431 256-714-5882 (cell) 256-963-6218 (fax) jim.wi...@adtran.com From: Finlayson Joe-G3162C [mailto:joefinlay...@motorola.com] Sent: Thursday, November 30, 2006 2:16 PM To: JIM WIESE; Gelfand, David; emc-p...@ieee.org Subject: RE: GR-1089 Issue 4 and Surge on Ethernet Jim, I am not sure I understand your explanation of the location of the surge protection device with respect to the primary or secondary side of the transformer. The way I look at this requirement, the key is to *not* provide a path, direct or through a protection device, back to Ground (C.O. Ground, Shelf Ground, Frame Ground, Earth Ground, etc.). If there is surge protection on either side of the transformer and it is either not referenced to Ground at all or referenced to Logic Ground only, the exemption can be taken. While referencing Logic Ground on the line (surge) side of the transformer or Shelf Ground on the PHY side of the transformer makes no practical sense, it can still be done. Therefore, physical location of the surge protection device may not necessarily dictate the ability to take this exemption. Would you agree with that? Also, can you please clarify on the intent of Section 4.6.9.1.1? Referencing Section 4.6.9.1.1, Equipment Ports With Secondary Protection, was the intent to label this section, Equipment Ports With Secondary Protection Not Referenced to Ground and only apply that to the longitudinal surges if the following conditions are met? 1.) The port does not have any secondary voltage-limiting protection to ground 2.) The unused pins of the port are not grounded solidly. ...or does this section apply to the metallic surges as well? Thx, Joe ~~ Joe Finlayson Tel: (508) 357-8273 Fax: (508) 357-8289 Email: joefinlay...@motorola.com Motorola, Inc. Embedded Communications Computing 46 Lizotte Drive Marlborough, MA 01752 USA ~~ From: JIM WIESE [mailto:jim.wi...@adtran.com] Sent: Wednesday, November 29, 2006 3:16 PM To:
Re: 4 wire resistance measurement lead set
The old HP 4328A (I think there is a 4328B modern digital version) used a 1 kHz ac waveform and averaged the readings to zero out any galvanic potentials. Also it used very small potentials and currents so that it would not punch through any dielectric build-up or corrosion within the bond being measured. The latter property is important if you are measuring the surface conduction properties of a complex material. For EMI, as opposed to lightning or safety ground measurements, I think it was the best milliohmmeter ever made. From: Garnier, David S (GE Healthcare) david.garn...@med.ge.com List-Post: emc-pstc@listserv.ieee.org Date: Thu, 30 Nov 2006 15:11:06 -0500 To: emc-p...@ieee.org Subject: 4 wire resistance measurement lead set Hello, Problem: Would like to evaluate surface conductivity of different types of metals... 1) Can anyone suggest a commercial 4 wire lead set for conducting these measurements? 2) Or, commercially available product or test fixture for measuring surface conductivity of different metals or coatings there of? 3) How does one measure Galvanic action between two dissimilar metals? Thank you for your time. Regards, Dave Garnier David Garnier e GE Health Care ___ David S. Garnier Senior Technician Functional CT Engineering 3000 N. Grandview Ave - M/S W-1250 Waukesha, Wi. 53188 Tel: 262.312.7246 Cel: 414.899.7580 - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list.Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to emc-p...@ieee.org Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: emc-p...@daveheald.com All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc __ This email has been scanned by the MessageLabs Email Security System. For more information please visit http://www.messagelabs.com/email __ - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to emc-p...@ieee.org Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: emc-p...@daveheald.com All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
RE: was EN61326 - standards' effective date interp
On Thu, 30 Nov 2006 06:54:46 -0800, Brian O'Connell oconne...@tamuracorp.com wrote: Ok, so what is the correct interpretation of requirements when the DoP and/or DoW for a standard, as published on Cenelec.org, do not agree with what is published on the EU site; i.e., the OJ Still confused after all of these years... For directives such as EMCD, LVD, etc., we must see ``Date of cessation of presumption of conformity of the superseded standard'' as published in the OJ for the directive. If you are not sure, maybe you can find the explanation in CENELEC Guide 25. Regards, Tom Tomonori Sato vef00...@nifty.ne.jp URL: http://homepage3.nifty.com/tsato/ - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list.Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to emc-p...@ieee.org Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald:emc-p...@daveheald.com All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc __ This email has been scanned by the MessageLabs Email Security System. For more information please visit http://www.messagelabs.com/email __
RE: Regulatory Compliance stifles innovation?
Rich, You wrote Today, safety engineers don't think this way. So, an end-result safety standard would require a huge amount of re-invention of the safety engineer job! While I agree with you regarding Product Safety engineers in the field today, there is a group of System Safety engineers that have always (since 1962 when the concept began) taken the risk assessment and mitigation approach. Most of these operate in government systems or industries that are regulated (transportation, nuclear, etc.) It would serve the Product Safety community well to interface with the System Safety community so that there would be less reinvention of the wheel. One web link that might help is the International System Safety Society: http://www.system-safety.org/ The size and complexity of the systems may differ but the concepts are the same. Oscar Overton Product Safety Lexmark International, Inc. Confidentiality Notice: This email message, including any attachment(s), is for the sole use of the intended recipient(s) and may contain confidential information. Any unauthorized review, use, disclosure, or distribution is strictly prohibited. If you are not the intended recipient please contact the sender, by email, and destroy all copies of the original message. Richard Nute rn...@san.rr.comTo: 'Tyra, John' john_t...@bose.com, emc-p...@ieee.org cc: Sent by: Subject: RE: Regulatory Compliance stifles innovation? emc-p...@ieee.org 11/30/2006 01:28 PM Please respond to richn Hi John: Unfortunately it is difficult for a Safety standard to keep up with new technology and the fairly broad wording makes it open for many different interpretations... If a safety standard was written as is an EMC standard, we would not have these problems. An EMC standard specifies the end-result, namely emissions not exceeding a certain value. The standard does not specify what needs to be done to the equipment to achieve the end- result, although the EMC report does include a description of the various emission control mechanisms. Today's safety standards do not specify the end-result. Instead, the standards specify various constructions deemed to make the product safe -- without saying how such construction makes the product safe. The safety report describes the constructions, but does not describe how the constructions make the product safe. Consequently, such safety standards cannot keep up with new technology. What if a safety standard specified the end-result, namely that injury shall be prevented? This is not as difficult as it may seem. For example, to prevent electric shock injury, the end-result would be that accessible parts shall not exceed a certain value (30 volts, for example). In keeping with current requirements, this end-result would apply under both normal operating conditions and single fault conditions. As with EMC, the standard would not need to describe what needs to be done to the equipment to achieve the end-result. As with EMC, the report would describe the constructions that prevent accessible parts from exceeding the limit, both for normal operating conditions and single fault conditions. Today, safety engineers don't think this way. So, an end-result safety standard would require a huge amount of re-invention of the safety engineer job! Best regards, Rich Richard Nute Product
RE: GR-1089 Issue 4 and Surge on Ethernet
Jim, I am not sure I understand your explanation of the location of the surge protection device with respect to the primary or secondary side of the transformer. The way I look at this requirement, the key is to *not* provide a path, direct or through a protection device, back to Ground (C.O. Ground, Shelf Ground, Frame Ground, Earth Ground, etc.). If there is surge protection on either side of the transformer and it is either not referenced to Ground at all or referenced to Logic Ground only, the exemption can be taken. While referencing Logic Ground on the line (surge) side of the transformer or Shelf Ground on the PHY side of the transformer makes no practical sense, it can still be done. Therefore, physical location of the surge protection device may not necessarily dictate the ability to take this exemption. Would you agree with that? Also, can you please clarify on the intent of Section 4.6.9.1.1? Referencing Section 4.6.9.1.1, Equipment Ports With Secondary Protection, was the intent to label this section, Equipment Ports With Secondary Protection Not Referenced to Ground and only apply that to the longitudinal surges if the following conditions are met? 1.) The port does not have any secondary voltage-limiting protection to ground 2.) The unused pins of the port are not grounded solidly. ...or does this section apply to the metallic surges as well? Thx, Joe ~~ Joe Finlayson Tel: (508) 357-8273 Fax: (508) 357-8289 Email: joefinlay...@motorola.com Motorola, Inc. Embedded Communications Computing 46 Lizotte Drive Marlborough, MA 01752 USA ~~ From: JIM WIESE [mailto:jim.wi...@adtran.com] Sent: Wednesday, November 29, 2006 3:16 PM To: Finlayson Joe-G3162C; Gelfand, David; emc-p...@ieee.org Subject: RE: GR-1089 Issue 4 and Surge on Ethernet David is correct, it is secondary protection. However, it does not cause you to loose the exemption from the metallic test in your case. To loose the exemption, the secondary protection component to ground would have to be on the opposite side of the transformer than the IC (surged side). That is the only way the longitudinal surge could be converted into a metallic surge. In your case, the isolation transformer prevents the conversion from a longitudinal to metallic surge, and you maintain the test exemption. Also as a clarification, C.O. ground is only partially correct. It depends upon where the equipment is deployed. Many locations such as EEC's (OSP cabinets), OSP equipment, and customer premises do not have C.O. grounds. GR-1089 covers the entire network. What is really meant by ground is earth ground. In a C.O. this is the same as frame ground, or C.O. ground. In the OSP or the customer premises, it is the protective earthing connection on the equipment which is supposed to be connected to earth ground. One thing to remember is that virtually all network equipment has the return side of the battery voltage connected to ground, and thus secondary protection components tied to -48VR for instance are considered grounded. Jim Jim Wiese NEBS Project Manager/Senior Compliance Engineer ADTRAN, Inc. 901 Explorer Blvd. Huntsville, AL 35806 256-963-8431 256-714-5882 (cell) 256-963-6218 (fax) jim.wi...@adtran.com From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Finlayson Joe-G3162C Sent: Wednesday, November 29, 2006 12:00 PM To: Gelfand, David; emc-p...@ieee.org Subject: RE: GR-1089 Issue 4 and Surge on Ethernet David, As that represents a path to Ground, then I would say that the answer is *Yes*. Keep in mind that the term Ground means C.O. Ground when referencing this topic. Thx, Joe ~~ Joe Finlayson Tel: (508) 357-8273 Fax: (508) 357-8289 Email: joefinlay...@motorola.com Motorola, Inc. Embedded Communications Computing 46 Lizotte Drive Marlborough, MA 01752 USA ~~ From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Gelfand, David Sent: Wednesday, November 29, 2006 12:38 PM To: emc-p...@ieee.org Subject: RE: GR-1089 Issue 4 and Surge on Ethernet Is a diode to ground on lines between the IC and the transformer considered secondary protection? Thanks, David David Gelfand Conformity Specialist / Specialiste de conformité 616 Curé-Boivin Boisbriand, Qc, Canada J7G 2A7 tel: (450)437-4661x2449 Fax: (450)437-8053 david.gelf...@ca.kontron.com From: emc-p...@ieee.org [mailto:emc-p...@ieee.org]On Behalf Of Nagel Michael-amn029 Sent: Wednesday, November 29, 2006 3:55 AM To: emc-p...@ieee.org Subject: GR-1089 Issue 4 and Surge on Ethernet Dear All, The Issue 4 of GR-1089 contains now (from my understanding) an exemption for Ethernet from the surge test 1 in Table 4-5 or 4-6 (metallic surge). Am I right with this interpretation? Is there any more information available on the history of the metallic surge test
4 wire resistance measurement lead set
Hello, Problem: Would like to evaluate surface conductivity of different types of metals... 1) Can anyone suggest a commercial 4 wire lead set for conducting these measurements? 2) Or, commercially available product or test fixture for measuring surface conductivity of different metals or coatings there of? 3) How does one measure Galvanic action between two dissimilar metals? Thank you for your time. Regards, Dave Garnier David Garnier e GE Health Care ___ David S. Garnier Senior Technician Functional CT Engineering 3000 N. Grandview Ave - M/S W-1250 Waukesha, Wi. 53188 Tel: 262.312.7246 Cel: 414.899.7580 __ This email has been scanned by the MessageLabs Email Security System. For more information please visit http://www.messagelabs.com/email __ - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to emc-p...@ieee.org Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: emc-p...@daveheald.com All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
RE: Regulatory Compliance stifles innovation?
Hello Rich, I agree with 100%!! Hopefully all the development work being done on the Hazard Based Safety Standards should get us closer to your EMC example by defining the end result as opposed to specific construction requirements. This would allow for innovative designs to be used as long as they could be proven to be safe. This would require us, as safety engineers, to perform Fault tree analysis on every product to identify the possible safety hazards but this should be done in any case for every product as the current safety standards try to identify specific safety concerns and as such can't possibly address every type of product design and hazard the product may present. It would be great if we could simplify the standards to level of the EMC standards as this would reduce grey areas and variations in interpretations between Agencies but may be more difficult then it seems With regard to your example regarding shock hazard it sounds like a good approach but I can see getting consensus on this from the various regulatory bodies as a challenge with regards to what type of isolation is required between hazardous voltage, i.e. mains, and the accessible voltage. Wouldn't it bring us back to the restrictions of the current standards of having to define insulation and spacing requirements for proper isolation?? In any case I do agree with you and would love to see the Safety standards move in this direction. Best regards, John From: Richard Nute [mailto:rn...@san.rr.com] Sent: Thursday, November 30, 2006 1:29 PM To: Tyra, John; emc-p...@ieee.org Subject: RE: Regulatory Compliance stifles innovation? Hi John: Unfortunately it is difficult for a Safety standard to keep up with new technology and the fairly broad wording makes it open for many different interpretations... If a safety standard was written as is an EMC standard, we would not have these problems. An EMC standard specifies the end-result, namely emissions not exceeding a certain value. The standard does not specify what needs to be done to the equipment to achieve the end- result, although the EMC report does include a description of the various emission control mechanisms. Today's safety standards do not specify the end-result. Instead, the standards specify various constructions deemed to make the product safe -- without saying how such construction makes the product safe. The safety report describes the constructions, but does not describe how the constructions make the product safe. Consequently, such safety standards cannot keep up with new technology. What if a safety standard specified the end-result, namely that injury shall be prevented? This is not as difficult as it may seem. For example, to prevent electric shock injury, the end-result would be that accessible parts shall not exceed a certain value (30 volts, for example). In keeping with current requirements, this end-result would apply under both normal operating conditions and single fault conditions. As with EMC, the standard would not need to describe what needs to be done to the equipment to achieve the end-result. As with EMC, the report would describe the constructions that prevent accessible parts from exceeding the limit, both for normal operating conditions and single fault conditions. Today, safety engineers don't think this way. So, an end-result safety standard would require a huge amount of re-invention of the safety engineer job! Best regards, Rich Richard Nute Product Safety Consultant San Diego Tel/FAX: +1-858-592-2620 Mobile: +1-858-776-1618 e-mail: ri...@ieee.org ri...@alumni.calpoly.edu - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list.Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to emc-p...@ieee.org Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald:emc-p...@daveheald.com All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc __ This email has been scanned by the MessageLabs Email Security System. For more information please visit http://www.messagelabs.com/email __
RE: Regulatory Compliance stifles innovation?
Hi John: Unfortunately it is difficult for a Safety standard to keep up with new technology and the fairly broad wording makes it open for many different interpretations... If a safety standard was written as is an EMC standard, we would not have these problems. An EMC standard specifies the end-result, namely emissions not exceeding a certain value. The standard does not specify what needs to be done to the equipment to achieve the end- result, although the EMC report does include a description of the various emission control mechanisms. Today's safety standards do not specify the end-result. Instead, the standards specify various constructions deemed to make the product safe -- without saying how such construction makes the product safe. The safety report describes the constructions, but does not describe how the constructions make the product safe. Consequently, such safety standards cannot keep up with new technology. What if a safety standard specified the end-result, namely that injury shall be prevented? This is not as difficult as it may seem. For example, to prevent electric shock injury, the end-result would be that accessible parts shall not exceed a certain value (30 volts, for example). In keeping with current requirements, this end-result would apply under both normal operating conditions and single fault conditions. As with EMC, the standard would not need to describe what needs to be done to the equipment to achieve the end-result. As with EMC, the report would describe the constructions that prevent accessible parts from exceeding the limit, both for normal operating conditions and single fault conditions. Today, safety engineers don't think this way. So, an end-result safety standard would require a huge amount of re-invention of the safety engineer job! Best regards, Rich Richard Nute Product Safety Consultant San Diego Tel/FAX: +1-858-592-2620 Mobile: +1-858-776-1618 e-mail: ri...@ieee.org ri...@alumni.calpoly.edu - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list.Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to emc-p...@ieee.org Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald:emc-p...@daveheald.com All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc __ This email has been scanned by the MessageLabs Email Security System. For more information please visit http://www.messagelabs.com/email __
RE: Regulatory Compliance stifles innovation?
Hi Greg: I have been trying to think of an example where the standard (IEC 60950-1:2001) requires a flame retarded material where no possibility of flame exists and cannot come up with one. I had a product where the main PWB was vertical and against one side of the product. The other side of the product was about 15 inches away from the board. (This type of construction is quite common in ink-jet printers!) There was no question the plastic side next to the board was required to be flame-retardant material. However, the other side, 15 inches away from the PWB, had no chance of ignition from any failure on the PWB, but the standard requires the side to be flame-retardant material. The power supplied to the PWB was not LPS, but was not much more than 100 watts. If you can imagine a 100-watt light bulb 15 inches away (in a horizontal line) from a vertically-oriented plastic material, I believe you can easily conclude that the radiated thermal energy at 15 inches is not likely to ignite the plastic material. In another case, the product was large and therefore the enclosure was required to be 5V. No problem. However, the mains switch was mounted on a small V0 part that was in turn attached to the 5V part. To comply, the small part had to be changed to 5V. Not quite to the point of your request, but these examples show that constructional standards do not allow for innovative design alternatives. Best regards, Rich - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list.Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to emc-p...@ieee.org Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald:emc-p...@daveheald.com All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc __ This email has been scanned by the MessageLabs Email Security System. For more information please visit http://www.messagelabs.com/email __
RE: was EN61326 - standards' effective date interp
Ok, so what is the correct interpretation of requirements when the DoP and/or DoW for a standard, as published on Cenelec.org, do not agree with what is published on the EU site; i.e., the OJ Still confused after all of these years... thanks, Brian -Original Message- From: emc-p...@ieee.org [mailto:emc-p...@ieee.org]On Behalf Of Jon Larkin Sent: Thursday, November 30, 2006 4:33 AM To: emc-p...@ieee.org Subject: Fw: EN61326 - recent changes and date product must comply Hey Chris, I think that you should buy the standard. Have a look at the Date Of Withdrawal (DOW) for when your product should comply with that standard, although this can be found on the CENELEC website (www.cenelec.org, and then put the standard number in the box in the top right). Jon - Original Message - From: Chris Wells cdwe...@adelphia.net To: IEEE Forum (E-mail) emc-p...@ieee.org Sent: Thursday, November 30, 2006 12:04 PM Subject: EN61326 - recent changes and date product must comply I did some googling on EN61326 this AM trying to find a summary of all the changes in EN61326 and didn't find any detail. Are there other changes to consider besides the higher RF range? Anyone have a web url to share? Date of compliance? I have a product that already is tested to EN61326 - then how long before I must comply to the new version? Isn't there a grace period? Thanks Chris Wells - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list.Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to emc-p...@ieee.org Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald:emc-p...@daveheald.com All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc __ This email has been scanned by the MessageLabs Email Security System. For more information please visit http://www.messagelabs.com/email __
RE: EN61326 - recent changes and date product must comply
I haven't done a line by line comparison, so cannot comment on the changes. However, you have until 1st Frebruary 2009 to comply, after which the conflicting standard will be withdrawn. Best regards Neil R. Barker CEng MIET FSEE MIEEE Manager Quality Engineering e2v technologies (uk) ltd 106 Waterhouse Lane Chelmsford Essex CM1 2QU UK Tel: (+44) 1245 453616 Fax: (+44) 1245 453571 Mob: (+44) 7801 723735 From: Chris Wells [mailto:cdwe...@adelphia.net] Sent: 30 November 2006 12:04 To: IEEE Forum (E-mail) Subject: EN61326 - recent changes and date product must comply I did some googling on EN61326 this AM trying to find a summary of all the changes in EN61326 and didn't find any detail. Are there other changes to consider besides the higher RF range? Anyone have a web url to share? Date of compliance? I have a product that already is tested to EN61326 - then how long before I must comply to the new version? Isn't there a grace period? Thanks Chris Wells Ian Yes - the 2006 edition of EN61326-1 goes up to 2.7GHz in 3 field strength bands. This is along with other requirements such as voltage sag testing. Ian Gordon Forum members With EN61000-6-2 : 2005 having moved the Radiated Immunity limit to 2.7GHz and having been informed through these listings that the IEC version of EN61326 is moving in the same direction could anyone inform me : If the EN version is moving that way and when. If the IEC version calling for this new upper limit is published. Thanks for your help in advance Ian White - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list.Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to emc-p...@ieee.org Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald:emc-p...@daveheald.com All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc __ This email has been scanned by the MessageLabs Email Security System. For more information please visit http://www.messagelabs.com/email __
EN61326 - recent changes and date product must comply
I did some googling on EN61326 this AM trying to find a summary of all the changes in EN61326 and didn't find any detail. Are there other changes to consider besides the higher RF range? Anyone have a web url to share? Date of compliance? I have a product that already is tested to EN61326 - then how long before I must comply to the new version? Isn't there a grace period? Thanks Chris Wells Ian Yes - the 2006 edition of EN61326-1 goes up to 2.7GHz in 3 field strength bands. This is along with other requirements such as voltage sag testing. Ian Gordon Forum members With EN61000-6-2 : 2005 having moved the Radiated Immunity limit to 2.7GHz and having been informed through these listings that the IEC version of EN61326 is moving in the same direction could anyone inform me : If the EN version is moving that way and when. If the IEC version calling for this new upper limit is published. Thanks for your help in advance Ian White - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list.Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to emc-p...@ieee.org Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald:emc-p...@daveheald.com All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc __ This email has been scanned by the MessageLabs Email Security System. For more information please visit http://www.messagelabs.com/email __
Antenna Pre-amps
Thanks for the many replies that I received. Bob Heller 3M EMC Laboratory, 76-1-01 St. Paul, MN 55107-1208 Tel: 651- 778-6336 Fax: 651-778-6252 = - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list.Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to emc-p...@ieee.org Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald:emc-p...@daveheald.com All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc __ This email has been scanned by the MessageLabs Email Security System. For more information please visit http://www.messagelabs.com/email __
