RE: HiPot testing of DC mains powered products
Rich - While I can't speak for Chris, there are a few reasons to perform production line ESTs on 48V dc mains powered equipment. 1) in 48Vdc SMPSs, the voltages present on transformer insulation are typically in excess of ELV limits. If the power supply has had fault testing performed that clearly indicates hazardous voltages are not presented at the outputs, there may be reason to waive an input-to-output production line EST. 2) unless the design and documentation explicitly address electrical bonding of the chassis to the battery return terminal in the equipment (refer to CSA/UL60950, Annex NAB and related information in Annex NAA), demonstration of electrical separation of battery return and chassis (protective earthing) is necessary. 3) quality control issues 4) customer requirements Regards, Peter L. Tarver, PE Product Safety Manager Sanmina Homologation Services peter.tar...@sanmina.com From: Rich Nute Hi Chris: I wonder why you need to hi-pot test a SELV-powered product? (I presume your external 48-volt dc source is SELV.) We make products intended for connection to an external dc source (SELV). We have never been required to perform a hi-pot test on such products. The production-line hi-pot is a test that tests the insulation between the two input leads (in parallel) and the chassis (or accessible metal). The insulation provides protection against electric shock. Since no electric shock is possible from 48 V dc (according to the standards), then there is no requirement for the insulation to withstand the transient overvoltages (if any) on the dc mains. Indeed, if the insulation were to fail, there would be no electric shock. Best regards, Rich --- 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: HiPot testing of DC mains powered products
I agree with Rich. Appendix D of your UL report or procedure has Exceptions to the standard dielectric and ground continuity tests done by the manufacturer. In my case I have 4 products which do not require either of these tests. I'd take a quick glance in your procedure. Gary -Original Message- From: Rich Nute [mailto:ri...@sdd.hp.com] Sent: Monday, November 12, 2001 4:34 PM To: chris.maxw...@nettest.com Cc: emc-p...@majordomo.ieee.org Subject: Re: HiPot testing of DC mains powered products Hi Chris: I wonder why you need to hi-pot test a SELV-powered product? (I presume your external 48-volt dc source is SELV.) We make products intended for connection to an external dc source (SELV). We have never been required to perform a hi-pot test on such products. The production-line hi-pot is a test that tests the insulation between the two input leads (in parallel) and the chassis (or accessible metal). The insulation provides protection against electric shock. Since no electric shock is possible from 48 V dc (according to the standards), then there is no requirement for the insulation to withstand the transient overvoltages (if any) on the dc mains. Indeed, if the insulation were to fail, there would be no electric shock. Best regards, Rich --- 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
There was also a very good (but short) article by Tektronix in the 70's called The Lethal Current. It concluded that currents between 100 mA and 3 Amps were more lethal that currents of more than 3 Amps because those high currents tended to 'restart' the heart. I think I will try not the check that out. Gregg PLEASE NOTE NEW NUMBERS P.O. Box 310, Reedville, Virginia 22539 USA Phone: (804) 453-3141 Fax: (804) 453-9039 Web: www.test4safety.com -Original Message- From: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of jrbar...@lexmark.com Sent: Monday, November 12, 2001 8:16 AM To: 'EMC-PSTC Discussion Group' Subject: 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. --- 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?
I have seen this in Section 6 of EN 55011:1990 Section 8 of EN 55022:1995 I'm not sure if there are any plans to remove these references from newer versions of these standards. Best regards, Chris -Original Message- From: David Heald [SMTP:davehe...@mediaone.net] Sent: Monday, November 12, 2001 3:59 PM To: 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. --- 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.
CISPR 11 and CISPR 22
Hi all Could somebody please send me the basic requirements for CISPR 11 emission limits I need to compare with CISPR 22 for a non radio product under EN60601-2. Best regards, Kim Boll Jensen Bolls Raadgivning Consultancy in world wide approvals attachment: kimboll.vcf
Re: 80/80 rule for euro compliance?
I read in !emc-pstc that Dan Irish - Sun BOS Hardware dan.ir...@sun.com wrote (in 2000.RAA05232@st- ides.East.Sun.COM) about '80/80 rule for euro compliance?', on Mon, 12 Nov 2001: 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 Not mysteriously, but not everyone in the world was told about it; that didn't seem necessary. (;-) deleted from CISPR16, and section 9 became Reserved for future use. I have the old version of CISPR16 buried in my paper files somewhere. CISPR 16 is a Basic Standard, covering methods of measurement and other product-independent matters. It is now in three Parts, CISPR16-1, -2 and -3. The subject is now dealt with in much greater detail in CISPR16-3. For ITE, CISPR16 was obsoleted by CISPR22. Not at all. CISPR 22 is a Product Family Standard, that refers to CISPR16 Parts where necessary. -- 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.
Re: 80/80 rule for euro compliance?
I read in !emc-pstc that David Heald davehe...@mediaone.net wrote (in 3bf037f8.c93b8...@mediaone.net) about '80/80 rule for euro compliance?', on Mon, 12 Nov 2001: 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? It's not peculiar to Europe, it's in many CISPR *international* standards, and thus appears in the corresponding (but not necessarily identical) EN 550xx series of European standards. -- 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.
Re: [Fwd: User Warning Signal Words]
I read in !emc-pstc that Rich Nute ri...@sdd.hp.com wrote (in 20030122.raa03...@epgc196.sdd.hp.com) about '[Fwd: User Warning Signal Words]', on Mon, 12 Nov 2001: I feel the authors of these definitions neither consulted a dictionary nor the users of warnings. I'm sure that you are right, but what is the alternative to using existing words but with special definitions that make their meanings more precise? If you solve this one, you clear up a significant problem in standards-writing. -- 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.
Re: CLASS 11(DOUBLE INSULATED) 2/3-CORE CABLE
I read in !emc-pstc that Rich Nute ri...@sdd.hp.com wrote (in 20022357.paa03...@epgc196.sdd.hp.com) about 'CLASS 11(DOUBLE INSULATED) 2/3-CORE CABLE', on Mon, 12 Nov 2001: Hi John: No; France and Norway have 'IT' systems, in which grounding is only to prevent static charge build-up; the neutral is grounded through an impedance at the sub-station. AIUI, this is used in mountainous districts where ground paths are long and of low conductivity. There are significant differences between the French and Norwegian systems. Can you please explain what those differences are? I don't know at present, but I may be able to find out next week. The explanation I have seen was said by some people in EDF to be wrong, and they should know! -- 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.
Re: Safety Critical etc - the future
I read in !emc-pstc that Rich Nute ri...@sdd.hp.com wrote (in 20022339.paa03...@epgc196.sdd.hp.com) about 'Safety Critical etc - the future', on Mon, 12 Nov 2001: 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). This could be confusing. SELV is usually NOT permitted to be grounded. The term 'Protected Extra-Low Voltage' (PELV) is now used for a source which is grounded but meets all the other requirements of SELV. In many fault conditions, PELV is much safer than SELV! A fault on an SELV system can persist undetected for a very long time, until a second fault, or intervention with the system, *quite unrelated*, occurs, and a very hazardous situation then arises. The earthing of PELV ensures, in almost all cases, that the first fault is not undetected and does not persist. -- 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.
Re: [Fwd: User Warning Signal Words]
According to ANSI Z35.4 the following definitions are provided: DANGER - Indicates an imminently hazardous situation which, if not avoided will result in death or serious injury. This signal word is to be limited to the most extreme situations. WARNING - Indicates a potentially hazardous situation which, if not avoided may result in minor or moderate injury. It may also be used to alert against unsafe practices. CAUTION - Indicates a potentially hazardous situation which, if not avoided may result in minor or moderate injury. It may also be used to alert against unsafe practices. Note: DANGER or WARNING should not be considered for property damage accidents unless personal injury risk appropriate to these levels is also involved. CAUTION is permitted for property-damage-only accidents. I feel the authors of these definitions neither consulted a dictionary nor the users of warnings. According to my Webster's Collegiate Dictionary: warn (verb): 1a: to give notice to beforehand, especially of danger or evil; 1b: to give admonishing advice to; 1c: to call to one's attention; 2: to order to go or stay away: to give a warning. So, all of the ANSI definitions serve to warn. warning (noun): 1: the act of warning: the state of being warned; 2: something that warns or serves to warn, especially a notice or bulletin that alerts the public that a tornado has been reported in the immediate vicinity or that the approach of a severe storm is imminent. So, all of the ANSI definitions are warnings. danger (noun): 1: (archaic); 2: (obsolete); 3: exposure or liability to injury, pain, harm, or loss a place where children could play without danger; 4: a case or cause of danger the dangers of mining. So, the word danger refers to a thing. caution (noun): 1: warning, admonishment; 2: precaution; 3: prudent forethought to minimize risk; 4: one that astonishes or commands attention some shoes you see these days are a caution. So, the word caution is defined as a warning. The so-called signal words are fabrications unrelated to the definitions of the words. This is a shame because it dilutes the power of the words. In my experience, users do not understand the subtle differences intended by the signal words. 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 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: RF Immunity Testing to 50V
-Original Message- From: Kevin Harris [mailto:harr...@dscltd.com] Sent: Monday, November 12, 2001 9:18 AM To: EMC-PSTC (E-mail) Subject: 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 Kevin: CDS can easily test to your needs (we can do +200 V/M, any modulation, 10 kHz to 18 GHz). Email me with details I'll get you a quote. I'm desperate to not have to get a part-time job this year as a mall Santa. 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 Services 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: 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: HiPot testing of DC mains powered products
Hi Chris: I wonder why you need to hi-pot test a SELV-powered product? (I presume your external 48-volt dc source is SELV.) We make products intended for connection to an external dc source (SELV). We have never been required to perform a hi-pot test on such products. The production-line hi-pot is a test that tests the insulation between the two input leads (in parallel) and the chassis (or accessible metal). The insulation provides protection against electric shock. Since no electric shock is possible from 48 V dc (according to the standards), then there is no requirement for the insulation to withstand the transient overvoltages (if any) on the dc mains. Indeed, if the insulation were to fail, there would be no electric shock. Best regards, Rich --- 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?
It is implied by the statistical analysis of a sample population during formal conformity assessment. Reference EN 55022:1998 Clause 7 (7.2.3) Regards, JOHN E. STUCKEY EMC Engineer NCT EMC 002047 Micron Technology, Inc. Quality and Reliability Assurance EMC Group M/S 941 3176 S. Denver Way Boise, Idaho 83705 PH: (208) 363.5313 FX: (208) 333.7302 jestuc...@micron.com -Original Message- From: Dan Irish - Sun BOS Hardware [mailto:dan.ir...@sun.com] Sent: Monday, November 12, 2001 15:24 To: emc-p...@majordomo.ieee.org Subject: 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. --- 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: CLASS 11(DOUBLE INSULATED) 2/3-CORE CABLE
Hi John: No; France and Norway have 'IT' systems, in which grounding is only to prevent static charge build-up; the neutral is grounded through an impedance at the sub-station. AIUI, this is used in mountainous districts where ground paths are long and of low conductivity. There are significant differences between the French and Norwegian systems. Can you please explain what those differences are? Thanks, and 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 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:
I read in !emc-pstc that Donald McElheran don...@hq.rossvideo.com wrote (in 808E4747B94FD511BDB0005004A1DE7F0521E3@HQ-EXCHANGE) about 'Group:', on Mon, 12 Nov 2001: The product being supplied via an external low voltage ( 20V DC @ 6A ) Do you mean 'less than 20 V'? The symbols and are often confused. 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. It is likely that the LVD will be revised within the foreseeable future to have no lower limit of voltage, like the RTTE Directive. 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. The input power is up to 120 W, which is quite enough to cause a significant fire hazard. Also, are any voltages higher than 20 V generated inside the box? You would be well-advised to apply the appropriate safety standard (IEC/EN60950/UL1950?), even if according to the letter of the law you may not need to. -- 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.
Re: Radio Module, full product re-test?
Hi Alex If you integrate the new radio module without change anything on the radio module I suggest to make no test on the product. Ciao Paolo At 13:36 11/12/01 +, Alex McNeil wrote: 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. -- Paolo Gemma Siemens Information and Communication Network spa Microwave Networks MW RD NSA EMC SS Padana sup. KM 158 20060 Cassina de'Pecchi (MI) Italy phone +39 02 9526 6587fax +39 02 9526 6203 mobile +39 348 3690185 e-mail paolo.ge...@icn.siemens.it --
Re: Define Continuous DC Voltage
Hi Dan: Does anyone know what voltage is used in electric chairs? Just Curious. I'm sorry you asked. The electric chair is one of the more barbarous methods of execution. The voltage is a function of time, and varies with the execution authority. The voltage is in the range of 1000-2000 volts, sometimes more, sometimes less. For more than you would ever want to know, including the voltage specs, see: http://www.theelectricchair.com/ You will need to use search the site to find voltage and other details. Be sure to read biology of electrocution. Also check out the botched electrocutions. Here are other sites I found as the result of a web search. The descriptions and pictures are gruesome and are not recommended. http://www.geocities.com/CapitolHill/6142/chair.html http://www.albany.edu/~brandon/sparky.html http://hypertextbook.com/facts/NancyRyan.shtml http://hypertextbook.com/facts/AprilDunetz.shtml http://members.aol.com/karlkeys/chair.htm http://www.pdimages.com/X0029.html-ssi http://www.suburbanchicagonews.com/joliet/prisons/chair2.html http://noop.rotten.com/chair/ http://library.thinkquest.org/23685/data/chair.html http://www.capitalcentury.com/1907.html http://www.fcc.state.fl.us/fcc/reports/methods/emappa.html http://www.hatchoo.com/deathrow/ http://www.ariel.com/au/jokes/The_Electric_Chair.html http://northstargallery.com/pages/Electric01.htm This site has some body impedance data taken during several executions. The descriptions and arguments are explicit and gruesome. http://www.dc.state.fl.us/oth/deathrow/drorder.html Calculate the power (E x I) dissipated in the body. Regards, Rich --- 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
Whoops!!! I was thinking wheel chair and on second thought I realized what you were thinking of was a means of intentional electrocution and execution. My mistake! -- From: Dan Kinney (A) dan.kin...@heapg.com To: Rich Nute ri...@sdd.hp.com, gkerv...@eu-link.com Cc: jrbar...@lexmark.com, emc-p...@majordomo.ieee.org Subject: RE: Define Continuous DC Voltage Date: Tue, Nov 13, 2001, 3:56 PM Does anyone know what voltage is used in electric chairs? Just Curious. Dan Kinney Horner APG Indianapolis -Original Message- From: Rich Nute [SMTP:ri...@sdd.hp.com] Sent: Tuesday, November 13, 2001 2:08 PM To: gkerv...@eu-link.com Cc: jrbar...@lexmark.com; emc-p...@majordomo.ieee.org Subject: Re: Define Continuous DC Voltage Hi Gregg: There was also a very good (but short) article by Tektronix in the 70's called The Lethal Current. It concluded that currents between 100 mA and 3 Amps were more lethal that currents of more than 3 Amps because those high currents tended to 'restart' the heart. Hmm. Having been the manager of product safety at Tektronix in the '70's, I don't recall such an article. At least not by that name. Electric energy causes various injuries to the body depending on the magnitude of the energy. Only two of the injuries can lead to a fatality. The two injuries are fibrillation of the heart, and overheating of internal organs, especially the liver. Fibrillation is caused by ac current in the range of 50 mA to 500 mA (external connections) where the current pathway through the body includes the chest (and the heart). Above 500 mA, fibrillation is not a likely consequence. (And, I believe I am correct in asserting that dc cannot cause fibrillation.) Overheating of internal organs is a function of power dissipated in the body, where the body impedance can be taken as 1000 ohms. The power required depends on the time of contact. Electric utility linemen are subject to such injury. Consider 1 ampere through 1000 ohms is 1000 watts! (The electric chair kills by over-heating the internal organs, not by fibrillation.) So, Gregg's statement that there is both a lower and upper limit for fibrillation is correct (although I do not agree with Gregg's values). Best regards, Rich --- 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. --- 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
I know of at least one that runs off a 12 Volt battery. I think it is a gel-cell but I KNOW it charges off an ordinary 12 Volt charger and it is supposed to be trickled charged nightly, so it is like a lead-acid in that it likes to be constantly charged and doesn't have memory. -- From: Dan Kinney (A) dan.kin...@heapg.com To: Rich Nute ri...@sdd.hp.com, gkerv...@eu-link.com Cc: jrbar...@lexmark.com, emc-p...@majordomo.ieee.org Subject: RE: Define Continuous DC Voltage Date: Tue, Nov 13, 2001, 3:56 PM Does anyone know what voltage is used in electric chairs? Just Curious. Dan Kinney Horner APG Indianapolis -Original Message- From: Rich Nute [SMTP:ri...@sdd.hp.com] Sent: Tuesday, November 13, 2001 2:08 PM To: gkerv...@eu-link.com Cc: jrbar...@lexmark.com; emc-p...@majordomo.ieee.org Subject: Re: Define Continuous DC Voltage Hi Gregg: There was also a very good (but short) article by Tektronix in the 70's called The Lethal Current. It concluded that currents between 100 mA and 3 Amps were more lethal that currents of more than 3 Amps because those high currents tended to 'restart' the heart. Hmm. Having been the manager of product safety at Tektronix in the '70's, I don't recall such an article. At least not by that name. Electric energy causes various injuries to the body depending on the magnitude of the energy. Only two of the injuries can lead to a fatality. The two injuries are fibrillation of the heart, and overheating of internal organs, especially the liver. Fibrillation is caused by ac current in the range of 50 mA to 500 mA (external connections) where the current pathway through the body includes the chest (and the heart). Above 500 mA, fibrillation is not a likely consequence. (And, I believe I am correct in asserting that dc cannot cause fibrillation.) Overheating of internal organs is a function of power dissipated in the body, where the body impedance can be taken as 1000 ohms. The power required depends on the time of contact. Electric utility linemen are subject to such injury. Consider 1 ampere through 1000 ohms is 1000 watts! (The electric chair kills by over-heating the internal organs, not by fibrillation.) So, Gregg's statement that there is both a lower and upper limit for fibrillation is correct (although I do not agree with Gregg's values). Best regards, Rich --- 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. --- 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.
Wiring - Single faults
As a military radar systems engineer I deal with various safety issues associated with aircraft radar systems. However, I have recently been looking at the safety of some associated benign environment test equipment comprising (at least in the context of safety) various simple 230v standard mains power commercial components. The connection mechanism for these internal components are, in some cases, tight push fit spade terminal type connections. The free terminal at the end of the connection wire is insulated with a recessed inner. The wire connection to this free spade connector is also covered with a heatshrink sleeve which provides additional insulation and containment for the wire. Thus if the wire joint somehow breaks, the wire remains insulated and held in place. This then provides adequate single fault containment as far as, say, wire breakage at the wire joint is concerned. Here is my very trivial question. What I can't get clear in my mind is this: If I wish, I can, of course, just completely pull the free connector off the component terminal. Is the complete disconnection of the spade terminal pair, with the free end now hanging loose, regarded as a single fault to be dealt with, or is this regarded as too gross to be considered a single fault? Any advice would be appreciated Regards Dave Palmer
RE: ULC vs. CUL
Perhaps they can reply if they are monitoring this forum, but I'll give it a shot... ULC is Underwriters Laboratories of Canada, and while they do product approvals, they generally in the past have not done the sort of product safety work that UL does. ULC has focussed more on building products for fire safety - things like fire doors, fire extinguishers, gas burning appliances, etc. Their approval mark looks much like the UL listing mark, but it's ULC, with the C inside the circle. The CUL mark has the C outside the circle, with the normal UL listing mark inside the circle, and maybe a US outside the circle as well. This mark is used by UL for product safety approvals where it needs to be made clear whether the requirements used were only US ones (read UL standards), only Canadian ones (CSA standards), or both. Normally where it is only the UL standards, they will just use the normal UL mark without either the C or the US. When CSA requirements are included, the C(UL)US mark is used to make it clear that both country's requirements were met. If they truly are approving only to the CSA requirements, the C(UL) mark would be used without the US. Regards, Jim Eichner, P.Eng. Manager, Engineering Services Xantrex Technology Inc. Mobile Power web: www.xantrex.com http://www.xantrex.com Any opinions expressed are those of my invisible friend, who really exists. Honest. Jim Eichner, P.Eng. Manager, Engineering Services Xantrex Technology Inc. Mobile Power phone: (604) 422-2546 fax: (604) 420-1591 e-mail: jim.eich...@xantrex.com web: www.xantrex.com -Original Message- From: geor...@lexmark.com [mailto:geor...@lexmark.com] Sent: Tuesday, November 13, 2001 12:47 PM To: emc-p...@ieee.org Subject: Re: ULC vs. CUL There is a UL mark acceptable for the U.S. There was a c-UL mark, acceptable to both Canada and the U.S. The more correct mark from UL for the c-UL mark is now the c-UL-us mark, i.e. circled UL with small c outside lower left of circle and small us outside lower right of circle. I have never heard any of these referred to as a ULC mark. George Alspaugh burchj%andovercontrols@interlock.lexmark.com on 11/13/2001 03:18:12 PM Please respond to burchj%andovercontrols@interlock.lexmark.com To: emc-pstc%majordomo.ieee@interlock.lexmark.com cc:(bcc: George Alspaugh/Lex/Lexmark) Subject: ULC vs. CUL Someone from our UK office is asking if ULC is the same as CUL. Does anyone know the difference between these two marks? Your help is always appreciated. Thanks, Joe Josiah P. Burch Compliance Engineer II Andover Controls Corporation 300 Brickstone Square Andover,Ma 01810 (978)-470-0555 x335 (978)-470-3615 Fax --- 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: ULC vs. CUL
ULC is Underwriters Laboratories of Canada CUL is a Listing or classification mark from Underwriters Laboratories Inc. Note: I have only seen ULC come up in approvals of FIre Detection and Suppression Equipment. e.g. Fire Extinguishers etc. bur...@andovercontrols.com on 11/13/2001 03:18:12 PM Please respond to bur...@andovercontrols.com To: emc-p...@majordomo.ieee.org cc:(bcc: John Merrill/Aut/Schneider) Subject: ULC vs. CUL Someone from our UK office is asking if ULC is the same as CUL. Does anyone know the difference between these two marks? Your help is always appreciated. Thanks, Joe Josiah P. Burch Compliance Engineer II Andover Controls Corporation 300 Brickstone Square Andover,Ma 01810 (978)-470-0555 x335 (978)-470-3615 Fax Title: ULC vs. CUL Someone from our UK office is asking if ULC is the same as CUL. Does anyone know the difference between these two marks? Your help is always appreciated. Thanks, Joe Josiah P. Burch Compliance Engineer II Andover Controls Corporation 300 Brickstone Square Andover,Ma 01810 (978)-470-0555 x335 (978)-470-3615 Fax
AC, DC definitions and safety
my two cents worth About electric shock: I'm finding it hard to reconcile some of what I'm reading here with real world experience of electric shock, not saying anyone's wrong, just that evidence is open to interpretation. In particular the statement Dc does not cause either tetanus or fibrillation seems to be contrary to common experience, I'm using the meaning of 'tetanus' to be paralysis and 'fibrillation' as uncontrolled motion. The electrician's rule of thumb when working on domestic wiring was to always check the wire is dead, even though you isolated it, in case of bridging or faulty connection. The technique used was to brush the exposed conductor lightly with the back of the fingers. Any AC present will be noticeable as a tingle. DC would cause contraction of hand muscles which would cause the hand to withdraw from the conductor. The same teacher explained that this precaution saved lives. Should the hand be allowed to grasp a live conductor the paralyzing effect of DC would be more likely to cause injury, shock or death because the effect of the current on the hand muscles when grasping would increase the grip and prevent the hand being opened to break the circuit. In this case it is precisely tetanus of the body which is dangerous because it interferes with the ability to move away from the hazard. The effect of AC on the hand was not described at the time but the implication was that a similar amplitude AC shock would be less hazardous to health. The basic studies of the nervous system made long ago used crude voltaic cells (DC) across muscle tissue to demonstrate muscle action by electrical stimulation. Try it yourself and then see if you agree that DC causes neither tetanus nor fibrillation! Definition of DC for test purposes: I wonder if I've missed the point or not? Maybe the rules and instructions were written in good faith with the expectation that safety evaluation would include recognition of the intent of the designer and the purpose of the circuit. When the purpose of the circuit is to handle power (not information) then it doesn't matter what the power signal format is, AC or DC, low or high frequency, any mark-space ratio. Power is hazardous to health in all its forms. It would seem to be in bad faith to ask what the definition of DC is for safety purposes if the intent of the evaluation is to promote safety. Best Regards Ted Rook Crest Audio 201 909 8700 ext 213 --- 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: ULC vs. CUL
Joe, The ULC mark is describe at the following link. http://www.ulc.ca/marks.asp http://www.ulc.ca/marks.asp John Juhasz Fiber Options Bohemia, NY -Original Message- From: bur...@andovercontrols.com [mailto:bur...@andovercontrols.com] Sent: Tuesday, November 13, 2001 3:18 PM To: emc-p...@majordomo.ieee.org Subject: ULC vs. CUL Someone from our UK office is asking if ULC is the same as CUL. Does anyone know the difference between these two marks? Your help is always appreciated. Thanks, Joe Josiah P. Burch Compliance Engineer II Andover Controls Corporation 300 Brickstone Square Andover,Ma 01810 (978)-470-0555 x335 (978)-470-3615 Fax
Re: CISPR 11 and CISPR 22
I read in !emc-pstc that Kim Boll Jensen kimb...@post7.tele.dk wrote (in 3bf0ed95.d6886...@post7.tele.dk) about 'CISPR 11 and CISPR 22', on Tue, 13 Nov 2001: Could somebody please send me the basic requirements for CISPR 11 emission limits I need to compare with CISPR 22 for a non radio product under EN60601-2. This question is really ill-advised. You need to see the WHOLE of a standard, not just a small part of it. There are notes and cross- references etc. that can considerably alter the apparent meaning of any text taken out of context. You are also quite likely to be given information from an out-of-date issue of the standard. Pay up your USD75 or whatever, and have your very own copy to keep. NOTE ALSO that you need to look at EN55011 for Europe. While the EN550xx series are BASED ON the CISPRxx series, they are NOT identical. -- 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.
RE: ULC vs. CUL
Joe, Some info on the various marks is available at: http://www.ul.com/mark/index.html http://www.ulc.ca/marks.asp Regards, Kaz Gawrzyjal Dell Computer Corp. -Original Message- From: bur...@andovercontrols.com [mailto:bur...@andovercontrols.com] Sent: Tuesday, November 13, 2001 2:18 PM To: emc-p...@majordomo.ieee.org Subject: ULC vs. CUL Someone from our UK office is asking if ULC is the same as CUL. Does anyone know the difference between these two marks? Your help is always appreciated. Thanks, Joe Josiah P. Burch Compliance Engineer II Andover Controls Corporation 300 Brickstone Square Andover,Ma 01810 (978)-470-0555 x335 (978)-470-3615 Fax --- 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 Rich Nute ri...@sdd.hp.com wrote (in 20031830.kaa06...@epgc196.sdd.hp.com) about 'AW: Define Continuous DC Voltage', on Tue, 13 Nov 2001: Hi John: I have never been very keen on the concept of SELV, and I am glad to see that others are now recognizing the problems. Interesting statement. In contrast, I don't see how we can get along without SELV. My concept for SELV is that of ELV so protected from a higher voltage such that in the event of a fault, the SELV does not exceed the ELV limits. SELV can protect under single fault conditions. BUT, as I tried to explain, under some conditions, it can allow a single fault *to persist undetected*, until eventually a second, unrelated fault occurs which then results in a serious hazard. My concept for ELV is a voltage source that provides protection against electric shock by limitation of voltage. (ELV is not protected against an increase in voltage in the event of a fault.) Well, there is FELV (Functional ELV), which is protected by basic insulation only. ELV/SELV are important and extremely useful concepts because they allow access to low voltages such as those that become accessible during the interconnection of various units. As one example, consider the camcorder. SELV allows access to the battery charger terminals. Making these terminals inaccessible would increase the complexity and cost of a camcorder. For a single piece of equipment or a small collection very close together, SELV may be sufficient. But notice that if the double or reinforced insulation WERE to be faulty, the SELV would be S no longer. This is simply regarded as an event of acceptably low probability. Now consider the case of a video camera and recorder, connected via a cable carrying video on coax and power at SELV, some distance apart in a building. Contact between live mains and the video cable shield, due to an errant nail or screw, puts live mains on the shield, BUT the fault may remain undetected until someone tries to disconnect the cable or open one of the enclosures. With PELV, this does not happen: the grounding ensures that the protective device operates. I cannot imagine that you truly are not keen on the concept of SELV. I can imagine that you are not keen on the complexity of voltage limits for ELV/SELV. To this, I agree. Well, perhaps I have made it clearer now. My beef with SELV is the ban on grounding, whereas PELV which is grounded AND double/reinforced insulated is clearly safer for systems extended in space. -- 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.
Re: Define Continuous DC Voltage
I read in !emc-pstc that Rich Nute ri...@sdd.hp.com wrote (in 20031730.jaa05...@epgc196.sdd.hp.com) about 'Define Continuous DC Voltage', on Tue, 13 Nov 2001: Dc does not cause either tetanus or fibrillation. Tetanus is a disease caused by a bacillus. Muscles spasm is tetany. -- 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.
Re: [Fwd: User Warning Signal Words]
Hi John: I feel the authors of these definitions neither consulted a dictionary nor the users of warnings. I'm sure that you are right, but what is the alternative to using existing words but with special definitions that make their meanings more precise? If you solve this one, you clear up a significant problem in standards-writing. Well... I guess I didn't make my point. The ANSI standard defines three classes of signal words. My point is that the actual signal word is largely unimportant to warning (the verb) the user. The signal word calls attention to the warning. The classes of attention-getting simply are not recognized by users (and are not consistent with dictionary definitions of the words). One could just as well use any of the described signal words (and maybe some others as already suggested here) or various suitable symbols for any of the severity classes of warnings. The degree of detail in specifying classes for signal words is not warranted. Delete these specific requirements for signal words from the standards. (We are over-standardized in this case.) Instead, concentrate on effective content of the warning. Best regards, Rich --- 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: ULC vs. CUL
There is a UL mark acceptable for the U.S. There was a c-UL mark, acceptable to both Canada and the U.S. The more correct mark from UL for the c-UL mark is now the c-UL-us mark, i.e. circled UL with small c outside lower left of circle and small us outside lower right of circle. I have never heard any of these referred to as a ULC mark. George Alspaugh burchj%andovercontrols@interlock.lexmark.com on 11/13/2001 03:18:12 PM Please respond to burchj%andovercontrols@interlock.lexmark.com To: emc-pstc%majordomo.ieee@interlock.lexmark.com cc:(bcc: George Alspaugh/Lex/Lexmark) Subject: ULC vs. CUL Someone from our UK office is asking if ULC is the same as CUL. Does anyone know the difference between these two marks? Your help is always appreciated. Thanks, Joe Josiah P. Burch Compliance Engineer II Andover Controls Corporation 300 Brickstone Square Andover,Ma 01810 (978)-470-0555 x335 (978)-470-3615 Fax --- 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.
ULC vs. CUL
Someone from our UK office is asking if ULC is the same as CUL. Does anyone know the difference between these two marks? Your help is always appreciated. Thanks, Joe Josiah P. Burch Compliance Engineer II Andover Controls Corporation 300 Brickstone Square Andover,Ma 01810 (978)-470-0555 x335 (978)-470-3615 Fax
Re: Define Continuous DC Voltage
Hi Gregg: There was also a very good (but short) article by Tektronix in the 70's called The Lethal Current. It concluded that currents between 100 mA and 3 Amps were more lethal that currents of more than 3 Amps because those high currents tended to 'restart' the heart. Hmm. Having been the manager of product safety at Tektronix in the '70's, I don't recall such an article. At least not by that name. Electric energy causes various injuries to the body depending on the magnitude of the energy. Only two of the injuries can lead to a fatality. The two injuries are fibrillation of the heart, and overheating of internal organs, especially the liver. Fibrillation is caused by ac current in the range of 50 mA to 500 mA (external connections) where the current pathway through the body includes the chest (and the heart). Above 500 mA, fibrillation is not a likely consequence. (And, I believe I am correct in asserting that dc cannot cause fibrillation.) Overheating of internal organs is a function of power dissipated in the body, where the body impedance can be taken as 1000 ohms. The power required depends on the time of contact. Electric utility linemen are subject to such injury. Consider 1 ampere through 1000 ohms is 1000 watts! (The electric chair kills by over-heating the internal organs, not by fibrillation.) So, Gregg's statement that there is both a lower and upper limit for fibrillation is correct (although I do not agree with Gregg's values). Best regards, Rich --- 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: RF Immunity Testing to 50V
Hi Kevin, we too can achieve high fields, currently about 80 v/m is our limit. Again, you may want to talk more offline Best regards, Derek. --- 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
Hi Chris: I'll attempt to answer the question as to the effect of ac and dc current on the body (the hazard). The discussion is in regard to three waveforms: 1) ac sinusoidal -- 50-60 Hz. 2) dc 3) dc interrupted (equal on and off times) up to 200 Hz. Each has a different effect on the body. For each waveform, the magnitudes of voltage and current at which the effect takes place are different. The body is most sensitive to ac, where the current reverses through the body. Such currents can cause both tetanus of various muscles, and fibrillation of the heart. Dc does not cause either tetanus or fibrillation. Dc with ripple or superimposed ac is still dc because the current does not reverse direction. From my reading of research papers, there is no significant effect on the body due to ac riding on a dc bias provided the current does not change direction. Interrupted dc (50% duty cycle, 0 mA off, up to 200 Hz) is surmised to have similar effect to that of ac. I believe that UL modeled this, and came to the conclusion that such interruption could cause fibrillation. (I don't believe any tests on animals or people were actually performed.) Hence, the limitation on voltage for such waveforms. Most of the research on live humans (grad students) was performed by Charles Dalziel, UC Berkeley, during the late 40's and early 50's. Dalziel published numerous papers on his tests, most in IRE and AIEE journals. Dalziel gave us the tetanus values for ac, and determined there was no tetanus for dc. Dalziel also gave us the effect of frequency on humans. During the 30's, 40's and 50's, UL also did some measurements on live humans (UL employees) to determine body impedance. Most recently, Beigelmeier (Vienna) has measured himself. His research is the basis for much of the data in IEC 60479, effects of current on the human body. Almost all other research was either on live (anesthesized) animals or on cadavers. When discussing waveforms that are beyond the research, we must identify the injury we wish to prevent. If we are considering 40 V dc which has an on/off period of 1 second, then the person can disconnect himself from the source during the 0.5-second off period. So, this would be the same as a steady-state 40 V dc source which is deemed non-hazardous. Best regards, Rich ps: Charles Dalziel is the inventor of the GFCI. Subject: RE: Define Continuous DC Voltage Date: Fri, 9 Nov 2001 16:10:29 -0500 From: Chris Maxwell chris.maxw...@nettest.com To: Ken Javor ken.ja...@emccompliance.com, Tania Grant taniagr...@msn.com, Doug McKean dmck...@corp.auspex.com, EMC-PSTC Discussion Group emc-p...@majordomo.ieee.org Sadly, I can't give that frequency; but I think I know the reasoning behind Eric's question... AC signals under 200Hz are especially dangerous to humans because AC currents really screw up our nervous system and cause death by heart attack at very low currents. It only takes milliamps of 60Hz AC current to kill a human being. On the other hand, people can withstand far more current from a DC source because it doesn't have the same effect on our nervous system. (Come on, who hasn't put a 9V battery on their tongue to test it out?) I think that this is the reasoning that the referenced standard uses to give two limits for AC and DC. 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. Problem is...the standards don't give a graph or table of hazardous voltage vs. frequency, it just says DC and AC. Since we don't have access to the graph we really don't know what happens at ultra low frequencies. (Although I have a few rodents in my basement who are just asking to be test samples.) Of course, now there is the gray area of interpretation. (which keeps us all employed) For example, how would a safety engineer classify a 40V thermostat control signal (non current limited) with a five second hysteresis that prevents it from switching any faster than once every five seconds (0.2 Hz). Under normal conditions, this signal would switch once every couple of hours (0.00014Hz). Is this hazardous AC (after all it is 40V, and it does vary with time)? Or is it non-hazardous DC. Anybody want to tackle that question? It may help us to figure out Eric's initial problem. Remember to show your work...partial credit will be given :-) Just to show that I'm game... I'll take a stab. My opinion
