Re: Safety Critical etc - the future
Hi Peter: As I have already written, I feel that safety-critical component as well as safety-related component are terms that require more consideration than is necessary. Basically, as I understand what you have said, a safety- critical component is one where its failure creates a hazardous situation. A safety-related component is one where its failure does not create a hazardous situation, and a second component now provides protection. Rather, I prefer the term safeguard. A safeguard is a device or scheme that is specifically installed in a product to provide protection against a specific injury. Unless we know how the injury occurs, we cannot prevent the injury. If we know how the injury occurs, then we can install a safeguard to prevent injury. Those components that encapsulate into one single component the 2 safety layers that are normally used to isolate the operator (and others) from a hazard. I suggest that each of the two layers are safeguards. These safeguards cannot be encapsulated into a single component because each safeguard must be independent of the other such that it is not subject to the same failure mechanism. All components that -by there function- may create a hazardous situation when defective, direct or indirect. If we have a safeguard, then the product is safe as long as the safeguard is functional. The safeguard must be independent of equipment functional failure. So, I do not accept the thesis of safety-critical component and safety-related component. Both layers of a double insulation are in themselves not a safety critical component; once they are integrated into one part -called reinforced- they are. I disagree. Each insulation within a double-insulation scheme provides a safeguard function. Because it is a safeguard, I consider it safety-critical. The fact that most safety standards require protection in the event of a fault in Basic insulation does not denigrate Basic insulation to a non-safety-critical function. Double-insulation is distinctly different from reinforced insulation. Double insulation is a scheme employing two, independent insulations, Basic and Supplementary. Reinforced insulation is a single insulation whose performance is equivalent to double insulation. A supply transformer of a not grounded SELV is a safety critical component. A supply transformer of a grounded SELV is a safety related component. For me, whether or not the SELV output of a safety-isolating transformer is grounded is irrelevant. Two safeguards must be interposed between the mains and the SELV. In some situations, the grounding of the SELV output winding can serve as the required grounded barrier (a supplemental safeguard to the Basic insulation, the principal safeguard). The art of safety thinking is finding and recognizing these double protection layers in equipment, processes and concepts (or the lack thereof). I disagree. I especially disagree with characterizing safety thinking as an art. If it is an art, then only artists can know safety. Safety is a legitimate engineering discipline, although not yet developed to the point of being included in engineering curricula. Within HP, we think of safety in terms of the 3-block model: +---++--++---+ | hazardous || energy || body | | energy|---| transfer |---| susceptibilty | | source|| mechanism|| | +---++--++---+ A hazardous energy source is any energy source whose magnitude exceeds the body susceptibility to that energy. In engineering terms: hazardous energybody susceptibility non-hazardous energybody susceptibility The energy transfer mechanism is the way that energy is transferred to the body (usually by contact with the energy source). A safeguard is a device that replaces the energy transfer mechanism and prevents energy transfer. Usually, this is an energy attenuator. (Electrical insulation is an energy attenuator that prevents sufficient energy from being transferred to the body.) This is one way in which safety can be treated as an engineering discipline. Using this model, energy sources and transfer mechanisms can be quantified, and energy attenuators can be quantified. Safety in any given situation can be an engineering problem of interposing a safeguard between the hazardous energy source and the body. When we think of safeguards as being interposed between a hazardous energy source and the body, then we can easily identify the protection layers. This is a too-short and unfortunately incomplete overview of our view of product safety. Best regards, Rich Richard Nute Hewlett-Packard Company San Diego --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web
Re: 80/80 rule for euro compliance?
Hi All It is in CISPR 16-3 2000. Also in Goedbloed's EMC textbook (don't have bibliog. info handy), and Dvorak's 1981 IEEE EMC Symp paper. Subj:Re: 80/80 rule for euro compliance? List-Post: emc-pstc@listserv.ieee.org Date: 11/12/2001 5:29:24 PM Eastern Standard Time From: dan.ir...@sun.com (Dan Irish - Sun BOS Hardware) To: emc-p...@majordomo.ieee.org Dave, As I recall, this used to be in CISPR16 ...Radio Interference Measuring Apparatus and Methods, section 9. In later versions of CISPR16, this requirement was mysteriously deleted from CISPR16, and section 9 became Reserved for future use. I have the old version of CISPR16 buried in my paper files somewhere. For ITE, CISPR16 was obsoleted by CISPR22. The VCCI audit requirements per V-3/2000.04 were taken almost verbatim from this. Dan Date: Mon, 12 Nov 2001 15:58:32 -0500 From: David Heald davehe...@mediaone.net To: emc-p...@majordomo.ieee.org emc-p...@majordomo.ieee.org Subject: 80/80 rule for euro compliance? Greetings all, I remember hearing somewhere ( it seems that I found the answer somewhere but I can't remember) that there is a stipulation for European compliance that one should have 80% certainty that 80% of one's products are compliant. I have no idea where this idea originally came from or what standards it may apply to. Can anyone out there help me out? Dave --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: 80/80 rule for euro compliance?
Dave, As I recall, this used to be in CISPR16 ...Radio Interference Measuring Apparatus and Methods, section 9. In later versions of CISPR16, this requirement was mysteriously deleted from CISPR16, and section 9 became Reserved for future use. I have the old version of CISPR16 buried in my paper files somewhere. For ITE, CISPR16 was obsoleted by CISPR22. The VCCI audit requirements per V-3/2000.04 were taken almost verbatim from this. Dan Date: Mon, 12 Nov 2001 15:58:32 -0500 From: David Heald davehe...@mediaone.net X-Accept-Language: en MIME-Version: 1.0 To: emc-p...@majordomo.ieee.org emc-p...@majordomo.ieee.org Subject: 80/80 rule for euro compliance? Content-Transfer-Encoding: 7bit X-Resent-To: Multiple Recipients emc-p...@majordomo.ieee.org X-Listname: emc-pstc X-Info: Help requests to emc-pstc-requ...@majordomo.ieee.org X-Info: [Un]Subscribe requests to majord...@majordomo.ieee.org X-Moderator-Address: emc-pstc-appro...@majordomo.ieee.org Greetings all, I remember hearing somewhere ( it seems that I found the answer somewhere but I can't remember) that there is a stipulation for European compliance that one should have 80% certainty that 80% of one's products are compliant. I have no idea where this idea originally came from or what standards it may apply to. Can anyone out there help me out? Dave --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Job opening
We have a job opening for a qualified Product Safety Quality engineer. The offial job description and applicant contact information are in the attached document. Thank you for your time. Brodie Pedersen SW QA Engineer Nonin Medeical Inc. Plymouth MN 55447 USA jp qa engineer.doc Description: jp qa engineer.doc
Re: RF Immunity Testing to 50V
I assume that's 50 V/m. If you can do a CI type test on any attached cables up to 400 MHz that would reduce the required illumination spot size down to 40 cm and any test house which is capable of generating the usual RI levels will be able to achieve the higher level by moving the antenna closer. This is a purely technical, not specification-based response. -- From: Kevin Harris harr...@dscltd.com To: EMC-PSTC (E-mail) emc-p...@ieee.org Subject: RF Immunity Testing to 50V Date: Mon, Nov 12, 2001, 11:17 AM Hello Group, Does anybody know of a test lab being able to test small objects (less than 15cm in any axis) up to 50V (with 80% AM 1KHz tone) from 80MHz to 1GHz Best Regards, Kevin Harris Manager, Approval Services Digital Security Controls 3301 Langstaff Road Concord, Ontario CANADA L4K 4L2 Tel: +1 905 760 3000 Ext. 2378 Fax +1 905 760 3020 Email: harr...@dscltd.com mailto:harr...@dscltd.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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
German X-ray requirements for monitors
A monitor that is sold in Germany requires a RoV license number if the accelerating voltage exceeds 20 kV and the CRT is not intrinsically safe. A marking with the license number is required on the monitor and a copy of the license must be supplied with the product. If the product is private branded by the manufacturer owning the license, must the manufacturer file for a revision of the license to included the private branding information (e.g., brand and model number)? Is a new license required? Is any action required by the reseller who's brand name is on the product? Richard Woods Sensormatic Electronics Tyco International --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
80/80 rule for euro compliance?
Greetings all, I remember hearing somewhere ( it seems that I found the answer somewhere but I can't remember) that there is a stipulation for European compliance that one should have 80% certainty that 80% of one's products are compliant. I have no idea where this idea originally came from or what standards it may apply to. Can anyone out there help me out? Dave --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: Group:
Donald At the risk of pre-empting others with more time to give a comprehensive answer, within Europe this type of product would fall under the General Product Safety Directive 92/59/EEC http://europa.eu.int/eur-lex/en/lif/dat/1992/en_392L0059.html Currently this is rather vague on applicable standards, but I believe that it is in process of being amended to be harmonised standards-based directive like the LVD, RTTE Directives etc. This amendment may (already have been?)be passed this year to come into operation in 2003. As such, you would generally apply the same safety standard that would apply if the product were actually mains powered, e.g. EN60950 or EN60065. Obviously the requirements for the AC mains circuits would not apply but - in particular - the flammability requirements would be very applicable. In practice - and even if the new text is still vague - I have always thought that there was very little obvious alternative anyway - especially in countries like the UK where a due dilegence defence in law in necessary. Regards John Allen Thales Defence Communications Division Bracknell, UK -Original Message- From: Donald McElheran [mailto:don...@hq.rossvideo.com] Sent: 12 November 2001 15:41 To: emc-p...@ieee.org Subject: Group: Group: We are currently in the process of a new table top type product design which will be powered via an external internationally certified DC supply. I have been asked to determine what compliance standards will have to be applied to ensure that the product meets regulator compliance requirements. The appropriate EMC standards are quite straight forward but I am having more difficult nailing down product safety requirements. The product being supplied via an external low voltage ( 20V DC @ 6A ) appears to technically fall outside the scope of both the European LVD directive and North American NRTL certification requirements for products directly connected to the public mains. The product is similar to that of a laptop computer running from an wall mounted adapter. Questions have been raised regarding flammability of enclosure materials which will have a significant impact of the products cost. Could any member of the forum who may have had to address similar situation share there thoughts? At this point it would appear that provided we ensure the external power supply conforms to any applicable safety standards in which the equipment is to be marketed that their is no legislated (hate to use this term) requirements to safety certify the table top product. Comments? Donal McElheran Product Compliance Ross Video Ltd. --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RF Immunity Testing to 50V
Hello Group, Does anybody know of a test lab being able to test small objects (less than 15cm in any axis) up to 50V (with 80% AM 1KHz tone) from 80MHz to 1GHz Best Regards, Kevin Harris Manager, Approval Services Digital Security Controls 3301 Langstaff Road Concord, Ontario CANADA L4K 4L2 Tel: +1 905 760 3000 Ext. 2378 Fax +1 905 760 3020 Email: harr...@dscltd.com mailto:harr...@dscltd.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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: Varient Model on Fcc.
You are almost there. The FCC ID belongs to the original manufacture (or grantee) known as A in this example. However, if someone wnats to privite label the product, and sell under vendor B's name, he/she may simply replace the name, model, etc. with their own words, but keep the FCC ID the same. Obviously updating and necessary customer information and instructions. This does leave a trail open when a vendor (B) does not want the purchaser (Customer) to know where the product originated. The knowledge customer can simply to to the FCC web site and determine the original grantee. If the vendor (B) does not wish this trail, then he/she will have to re-certify the product with the FCC (actually the TCB now in most cases) and have a get a new Grantee (AKA - applicant's) code if one does not already exist. Vendor B, with the approval of Grantee A, would then apply for a new Grant of Equipment Authorization which authorized the new FCC ID to be used on the model sold by Vendor B without a paper trail back to Grantee A. Hopefully that clears up any confusion. John Shinn, P.E. Manager, Lab. Operations] Sanmina -Original Message- From: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of wo...@sensormatic.com Sent: Tuesday, November 06, 2001 9:58 AM To: emc-p...@majordomo.ieee.org Subject: RE: Varient Model on Fcc. It private branding of equipment A to become B is the issue, then there is no issue. The FCC ID belongs to the manufacturer of A and no change of the Grant is required. A new Grant would be required if the equipment were manufacturered by someone else. Richard Woods Sensormatic Electronics Tyco International -Original Message- From: John Juhasz [mailto:jjuh...@fiberoptions.com] Sent: Tuesday, November 06, 2001 12:35 PM To: 'Don Rhodes'; 'Jong Ho,Lee'; EMC-PSTC; EMC-PSTC Subject: RE: Varient Model on Fcc. I think what the question is here is not so much as 'Class' of emission levels I think he is refering to an OEM product. He is buying completed/fully-functional product A and will market it as product B. They are one in the same. His question is whether he can use (transfer) the FCC ID issued to product A on the marketed product B. I would like to know the same . . . John Juhasz Fiber Options Bohemia, NY -Original Message- From: Don Rhodes [mailto:don.rho...@infocus.com] Sent: Tuesday, November 06, 2001 11:23 AM To: 'Jong Ho,Lee'; EMC-PSTC; EMC-PSTC Subject: RE: Varient Model on Fcc. Tommy, I'm not exactly sure what you're asking. If you're asking if a Product which is labeled as Class A can be relabeled as a Class B product because they look the same, the answer is no. The product must be properly retested to assure its compliance with the Class B limits and then you must have a test report approved by the FCC. I have little doubt that if the two really were the same they would be labeled differently. Secondly, the FCC ID is a means of identifying the manufacturer. Therefore, unless your company is the holder of the FCC ID in question, I suggest you ask the printer manufacturer the question you're posing to the group. Respectfully, Don Rhodes EMC Engineering InFocus Corp. -Original Message- From: Jong Ho,Lee [mailto:upu...@samsung.com] Sent: Monday, November 05, 2001 8:50 PM To: EMC-PSTC; EMC-PSTC Subject: Varient Model on Fcc. Hi folk. A model has Fcc ID.It is Printer. Our buyer sale A model product to maket as B . There are not differnt between A and B. So I will use same Fcc ID on buyer model. Is it possible? If not,How can I do for get Fcc ID ? Best regards. Tommy --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute:
Re: Define Continuous DC Voltage
Chris, check out IEC 479-1 (Effects of current on human beings and livestock). Real interesting reading - it mainly analyzes human body impedances (measurements taken on living humans and corpses) and discusses physiological effects of AC in range of 15-100 Hz and DC. In their study, it appears that 10 mA (in this AC range) is the point above which harmful physiological effects can occur and around 25 mA for DC. Above these limits, time of exposure will determine the threat of permanent and harmful effects. They do indicate that the physiological effects experiments were conducted on animals and were adapted to human beings. Human corpses were used in gathering human body impedance measurements from 25V to 5000 V. Barbecue anyone? -Scott Lemon Chris Maxwell wrote: My GUESS is that someone (who loved to torture living organisms) must have performed tests to figure out how DC current affected people (or monkeys, or rats... something). They then must have performed tests with different AC frequencies. Perhaps they even plotted a graph of hazardous voltage/current versus frequency. I would imagine that this is the type of data used by the IEC or any other safety organizationn to set hazardous voltage levels. --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: Radio Module, full product re-test?
I read in !emc-pstc that Alex McNeil alex.mcn...@ingenicofortronic.com wrote (in 5685ADDE2285D511925200508BB9F5031EBD9F@FORT2) about 'Radio Module, full product re-test?', on Mon, 12 Nov 2001: I have an alternate Small Radio Device (SRD) Module, previous one obsoleted, in a product. This new alternate Radio Module has ETS 300 683 (EMC) and EN 300 220-1 (Radio) approvals and DoC supplied by the manufacturer. The product was already approved to these standards with the obsoleted module, plus EN55022 and EN55024. To Show Due Dilligence (CE Mark) What is the minimum I need to do for EMC re-verification, if any? Write a report for your technical file that explains why you consider you do not need to carry out a full re-verification. Then consider what *may* have changed as a result of changing the module. For example, if it is grounded differently from the old one, the antenna cable may now be carrying microprocessor (if there is one) clock signals at a higher amplitude than before. Carry out any tests you consider necessary to give confidence in your DOC for the modified end-product. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Eat mink and be dreary! --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Group:
Group: We are currently in the process of a new table top type product design which will be powered via an external internationally certified DC supply. I have been asked to determine what compliance standards will have to be applied to ensure that the product meets regulator compliance requirements. The appropriate EMC standards are quite straight forward but I am having more difficult nailing down product safety requirements. The product being supplied via an external low voltage ( 20V DC @ 6A ) appears to technically fall outside the scope of both the European LVD directive and North American NRTL certification requirements for products directly connected to the public mains. The product is similar to that of a laptop computer running from an wall mounted adapter. Questions have been raised regarding flammability of enclosure materials which will have a significant impact of the products cost. Could any member of the forum who may have had to address similar situation share there thoughts? At this point it would appear that provided we ensure the external power supply conforms to any applicable safety standards in which the equipment is to be marketed that their is no legislated (hate to use this term) requirements to safety certify the table top product. Comments? Donal McElheran Product Compliance Ross Video Ltd. --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Old LectroMagnetics shielded enclosure
Greetings, I have an old (circa 1986) LectroMagnetics shielded enclosure that I would like to modify. I'm looking for some parts and panels. It seems that LectroMagnetics (LMI inc.) are no longer around. Does anyone know if this product line (clamp together s.e.) has been taken over by another entity? I expect this is not of general interest to the list, so off-line replies appreciated. adTHANKS, Bob Sykes EMC Engineer Marconi Commerce Systems --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Radio Module, full product re-test?
Hi Group, Situation I have an alternate Small Radio Device (SRD) Module, previous one obsoleted, in a product. This new alternate Radio Module has ETS 300 683 (EMC) and EN 300 220-1 (Radio) approvals and DoC supplied by the manufacturer. The product was already approved to these standards with the obsoleted module, plus EN55022 and EN55024. To Show Due Dilligence (CE Mark) What is the minimum I need to do for EMC re-verification, if any? Kind Regards Alex McNeil Principal Engineer Tel: +44 (0)131 479 8375 Fax: +44 (0)131 479 8321 email: alex.mcn...@ingenicofortronic.com -Original Message- From: jim.hulb...@pb.com [mailto:jim.hulb...@pb.com] Sent: Friday, November 09, 2001 7:19 PM To: emc-p...@ieee.org Subject:CISPR 22:1997 The European Union has postponed mandatory compliance with CISPR 22:1997 (EN 55022:1998) until 1 August 2003. This version of the standard includes the new requirement for conducted emissions on cables connected to telecommunications ports. Have other countries that require compliance with CISPR 22 (or some variation thereof) also postponed implementation of the 1997 version? My immediate concern is Australia. Any information members of this group can share is greatly appreciated. Jim Hulbert Senior Engineer - EMC Pitney Bowes --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: Define Continuous DC Voltage
From my reading on the subject, EN 60950 has different Safety Extra-Low Voltage (SELV) limits for alternating current (AC) and direct current (DC) because the human body reacts to them differently. AC makes your muscles contract, so you tend to hang onto the source of the electric shock. DC makes you push away, removing contact, but you may fall or otherwise hurt yourself as you jerk away from the source of the shock. I have heard hams (amateur radio operators) tell of picking themselves off the floor, clear across the room, after accidently touching the plate supply of a tube radio. I found an article in Electronics magazine, published between 1940 and 1945 (I can't find the article right now), on a study that was done on let-go current. In this study the subjects (something like 100 young males) would grab a 1/4 wire with one hand, and put their other hand on a copper or brass plate. The experimenter would apply a voltage between the wire and the plate, giving the subject a shock. Then the subject would try to let go of the wire. If they couldn't, they could open the circuit just by lifting their hand from the plate. If the subject could let go of the wire, the experimenter would increase the voltage and they would try the experiment again. As I recall the experiments were done mainly at 50 and 60Hz, with some done at DC and low frequencies, and others up to 10kHz. The results of the study were that let-go current was lowest in the 40-100Hz range, and ranged from 15mA up to about 100mA. (I got the impression that some of the young men were trying to show how macho they were...) The let-go current increased as the frequency increased above 100Hz, or decreased below 40Hz. For DC the subjects had trouble trying to hold onto the wire, and instead of a shock they felt a heating effect. I have not seen any studies on how much AC superimposed on DC changes the let-go effect to a hang-on effect, and I don't plan to find out for myself if I don't have to... John Barnes Advisory Engineer Lexmark International --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: AW: Define Continuous DC Voltage
I read in !emc-pstc that Horst Haug innova...@t-online.de wrote (in nebbjgdeklhmddlcffinceancoaa.innova...@t-online.de) about 'AW: Define Continuous DC Voltage', on Sun, 11 Nov 2001: Enclosed are results of a SELV reliability test. The output inductance was shorted with no load and the ripple increased. In 1.2.13.4 (IEC60950) DC voltage is defined as a voltage with a peak to peak value less 10 % of the DC voltage. In the enclosed file you see the ripple with Peak 49,6 Vpmax and 42,4 Vpmin. The DC voltage is around 46 Vdc. 1. Now the argumentation could be: The voltage is not DC, because the ripple is above 10%. There is only AC or DC. Therefore, it has to be AC. The ripple is Vpeak max 49.6 V exceeding the defined max. peak of 42 V (2.2.2 of IEC60950). Therefore the output is not SELV any longer. This is a correct understanding of the definition of 'DC' used in several safety standards. 2. Another understanding is : The voltage is DC and AC. You have to split it into an AC part and a DC part. The DC part is 46 Vdc. This is a correct understanding of the *concept* of d.c. The AC part is 49,6 - 42,4 from peak to peak = 7,2 Vpeak to peak. Therefore it is SELV and pass. This is not a correct interpretation of the *safety standards*. It *is* a correct understanding of the *concept of a.c. This definition results in worse case into a 60 Vdc voltage overlayed with 42 V ripple resulting in Vpeak max of 81 V acceptable as SELV. If we agree with version 1, then it will be difficult to built up power supplies with nominal voltage of 48 Vdc. It is always easy to open a secondary cap or short a secondary inductance to increase the ripple above 10%. You are correct: 48 V is near enough to the upper limit of SELV to make preservation of conformity to the limit difficult under fault conditions. I have never been very keen on the concept of SELV, and I am glad to see that others are now recognizing the problems. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Eat mink and be dreary! --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
