NEBS questions
Hello Group: I am glad to see the recent NEBS related discussions. I find them interesting and relevant. So while I am thinking about NEBS, I thought I'd ask a couple of questions. I would like to understand more clearly the relationship between Central Offices and local building codes. I understand that the NEC basically exempts CO's. And that would mean that any local AHJ adopting the NEC unchanged would have the same exemption. But I am wondering how the CO's themselves view the local building codes. Maybe they just ignore them, but perhaps they voluntarily try to meet them ? Of course there's a lot of the actual requirements that are covered by the NEBS requirements, but it would seem like some things (mains service entrance ?) may not be covered. Also, where exactly is the line that divides the exempt CO area from where the local codes are applicable ? As I think about it now, I don't recall the specific wording of the NEC's exemption, but It would seem that it would include any requirement for using Listed equipment or components. Although GR1089 does seem to require Listing for AC mains connected equipment, do some companies require Listing for equipment connected to the CO DC supply ? The benefit of your experience and thoughtful comments will be appreciated. Thanks Richard Payne Tektronix, Inc. Product Safety Engineering Tel: 503 627-1820 Fax: 503 627-3838 email: richard.pa...@tektronix.com --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
Stumped
Forum, I have made some measurements and gotten results which are at odds with my intuition. I am wondering if someone out there can shed some light on this subject. I was interested in the losses associated with rf traveling on a twisted shielded pair cable. The scenario is that a length of this TSP cable is exposed to an rf environment (as in a test chamber during IEC 1000-4-3 testing) and then the cable penetrates a bulkhead using a grounded connector that provides excellent shield termination, and the cable continues on the other side in the pristine rf environment of a shielded control chamber, say for several meters. The question is, how much rf signal is at the final destination point vs. at the bulkhead. The concern is common mode, not differential mode. Meaning that the twisted pair can be looked at like coax, with an identical signal on both inner conductors relative to the shield. I expected losses that would be on the same order or lower than that associated with off-the-shelf coax types like RG-58. Instead my losses were dramatically higher. Following is my measurement technique. I measured the transmission line impedance of the TSP in the following way. I tied the center conductors together. I shorted the center conductors to the shield at one end, and measured the inductance, using an LCR meter. I opened the connection and measured the open circuit capacitance. The square root of the l/c ratio is the characteristic impedance. I built matching networks to get from 50 Ohms to the measured impedances which ranged from 15 - 25 Ohms for a variety of different cables. For each cable, I built two pairs of identical matching networks: 4 each: 50 to RC adapters I used an HP 4195A network analyzer, over a range of frequencies 0.1 - 500 MHz. The set up was as follows. There was 16 dB of pad coming out of the source (including the 6 dB splitter). There was 10 dB of pad at the reference and test ports. Results showed little evidence of vswr. Coming out of the source, there is the 6 dB splitter. Between one port of the splitter and the reference port, I inserted one pair of the matching networks: Splitter output connects to 50 Ohm to RC adapter connects to RC to 50 Ohm adapter connects to reference port. I connected the exact same sequence between the other splitter output and the test port. The network analyzer displayed the dB ratio of the test port signal relative to the reference signal. This would be the difference in loss between each pair of matching networks. If I had built them perfectly, the analyzer should have shown 0 dB difference. Actual differences were under 3 dB. Then I inserted the cable-under-test between the RC connections on the two matching networks in the test port side. The loss associated with cable-under-test (CUT) is the difference between the losses measured with the CUT in place and with the matching networks directly connected. The numbers I got were considerably higher than even a high loss coax such as RG-174. Because real coax uses a much thicker dielectric material than just the insulation around a TSP center conductor, my gut feel is that losses should be lower than for 50 Ohm coax. I expect that materials picked to be dielectrics for coax have low loss tangents relative to wire insulation, but I don't have a feel for whether the difference in loss tangents can make up for the extra thickness of the dielectric in real coax. Can any one tell me if either my test set up or my expectations are wrong, and why? Thank you. Ken Javor --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
RE: NEBS Level 3 Plus
Richard, Verizon does not recognize NEBS Level 3 as called out in Telcordia/Bellcore SR-3580. They had input into this document, but later regretted it. What Verizon does recognize is their own checklist at www.verizonnebs.com http://www.verizonnebs.com/ . The confusion comes from the fact that the SR-3580 requirements are scattered throughout Verizon s checklist. At the NEBS 2002 Conference last week, Verizon introduced their latest revision of their checklist. They are trying to incorporate all of the other RBOCs and ATT requirements into this document. I caution everyone to obtain the specific checklists/requirements from each or your potential customers and comply with them. NEBS Plus is mentioned in an article I wrote for Evaluation Engineering What Every Startup Needs to Know About NEBS: http://www.evaluationengineering.com/archive/articles/0502emc.htm The intent was to highlight that just meeting NEBS Level 3 was not enough to get equipment into your customers central offices. In summary, there is no NEBS Level 3 Plus requirement, there are only customer requirements. Best regards, Dave Lorusso Lorusso Technologies, LLC Your NEBS, Product Safety and EMC Solution www.lorusso.com http://www.lorusso.com/ www.nebs-faq.com http://www.nebs-faq.com/ 512.695.5871 (phone) 512.233.2939 (fax) -Original Message- From: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of Georgerian, Richard Sent: Monday, October 14, 2002 11:10 AM To: IEEE emc-pstc Subject: NEBS Level 3 Plus Greetings All, Does anyone know the specifics regarding Verizons NEBS Level 3 Plus requirement. I have checked the Verizon web pages, the archives of the emc-pstc, and the word search on the internet, with no luck. Otherwise, I believe this is just another name for the checklist document that Verizon uses and can be downloaded from their website. Thanks in-advance. Richard Georgerian Compliance Engineer Carrier Access Corporation 5395 Pearl Parkway Boulder, CO 80301 USA Tele: 303-218-5748 Fax: 303-218-5503 mailto:rgeorger...@carrieraccess.com * This e-mail transmission, and any documents, files, or previous e-mail messages attached to it may contain information that is confidential or legally privileged. If you are not the intended recipient, or a person responsible for delivering it to the intended recipient, you are hereby notified that you must not read this transmission and that any disclosure, copying, printing, distribution, or use of any of the information contained in or attached to this transmission is strictly prohibited. If you have received this transmission in error, please immediately notify the sender by telephone or return e-mail and delete the original transmission and its attachments without reading or saving them in any manner. Thank you. *
Re: Ground potential differences
The worst case of ground potential difference that I have heard of is a case where guy got a shock from the grounded metal reflector of his trouble light while working outside on his car. Turns out the pump in his neighbor's well (fed from the same transformer) had a short from from line to ground. The potential difference between the ground tied to line at the neighbor's and the ground tied to neutral at this guy's house caused a voltage gradient along ground between the properties high enough to cause a shock when enough distance was covered (by the cord of the trouble light). Don Borowski Schweitzer Engineering Labs Pullman, WA This e-mail may contain SEL confidential information. The opinions expressed are not necessarily those of SEL. Any unauthorized disclosure, distribution or other use is prohibited. If you received this e-mail in error, please notify the sender, permanently delete it, and destroy any printout. Thank you. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
RE: NEBS Level 3 Plus
About 6-7 years ago when I was getting ready to go through NEBS for the first time, I found it to be confusing and in some cases daunting. At that time, Bellcore (now Telcordia) put on a NEBS seminar with a NEBS rep from each of the operating companies. That seminar proved to be the key that put it all together for me and made the job easier. Further, the operating companies' representatives made themselves available to answer questions specific to your product. This alone was worth it's wait in gold. And if I had any further questions, I could contact them at their offices. If you can find a NEBS seminar that has reps from the operating companies, I suggest making the investment. I believe there are several choices other than Telcordia for these seminars. Check around. As the testing is so expensive, you want to do it right the first time. Just my opinion . . . John A. Juhasz GE Interlogix Fiber Options Div. Bohemia, NY Original Message- From: Georgerian, Richard [mailto:rgeorger...@carrieraccess.com] Sent: Monday, October 14, 2002 12:10 PM To: IEEE emc-pstc Subject: NEBS Level 3 Plus Greetings All, Does anyone know the specifics regarding Verizons NEBS Level 3 Plus requirement. I have checked the Verizon web pages, the archives of the emc-pstc, and the word search on the internet, with no luck. Otherwise, I believe this is just another name for the checklist document that Verizon uses and can be downloaded from their website. Thanks in-advance. Richard Georgerian Compliance Engineer Carrier Access Corporation 5395 Pearl Parkway Boulder, CO 80301 USA Tele: 303-218-5748 Fax: 303-218-5503 mailto:rgeorger...@carrieraccess.com * This e-mail transmission, and any documents, files, or previous e-mail messages attached to it may contain information that is confidential or legally privileged. If you are not the intended recipient, or a person responsible for delivering it to the intended recipient, you are hereby notified that you must not read this transmission and that any disclosure, copying, printing, distribution, or use of any of the information contained in or attached to this transmission is strictly prohibited. If you have received this transmission in error, please immediately notify the sender by telephone or return e-mail and delete the original transmission and its attachments without reading or saving them in any manner. Thank you. *
Re: Ground potential differences
I've no publications, but I did have personal experience with the more destructive results with ground potential differences. At another company, I witnessed the insulation of a coax cable melting after being connected between equipment in a lab where I worked. The problem being a difference in ground potential of 15vac. That in and of itself wasn't the problem. The amperage capacity through ground of the mains system was the culprit. Circa 1983 or so. Turned out that the building was supplied by two electrical substations at opposite ends of the building. And for some strange reason, the substations each shared about half the outlets in the lab. And the potential difference was caused by the electricians connecting to slightly different points on the transformers for ground. The electricians were told and were able to fix the problem. And as far as anything in the field showing a similar problem, I have only dealt with one such instance. And relating the substation transformer ground tap story fixed it for them. Regards, Doug McKean --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
NEBS Level 3 Plus
Greetings All, Does anyone know the specifics regarding Verizons NEBS Level 3 Plus requirement. I have checked the Verizon web pages, the archives of the emc-pstc, and the word search on the internet, with no luck. Otherwise, I believe this is just another name for the checklist document that Verizon uses and can be downloaded from their website. Thanks in-advance. Richard Georgerian Compliance Engineer Carrier Access Corporation 5395 Pearl Parkway Boulder, CO 80301 USA Tele: 303-218-5748 Fax: 303-218-5503 mailto:rgeorger...@carrieraccess.com * This e-mail transmission, and any documents, files, or previous e-mail messages attached to it may contain information that is confidential or legally privileged. If you are not the intended recipient, or a person responsible for delivering it to the intended recipient, you are hereby notified that you must not read this transmission and that any disclosure, copying, printing, distribution, or use of any of the information contained in or attached to this transmission is strictly prohibited. If you have received this transmission in error, please immediately notify the sender by telephone or return e-mail and delete the original transmission and its attachments without reading or saving them in any manner. Thank you. *
RE: Ground potential differences
Most earth potential differences come from load currents. Leakage currents don't usually add up to very much. Electrical installations should have one neutral to earth connection at the source of the system (at the transformer or service entry). However many electrical installations have branch panels with earth and neutral incorrectly connected together at the panel. This means the neutral and earth paths are parallel returns to the source. The IR drop generates potential differences between different building areas. These stray currents can amount to tens or hundreds of amps in big installations. Occasionally these same currents come from miswired plugs or receptacles with neutral and earth switched. To look for stray currents, put a clamp on ammeter around all mains conductors together (phases and neutral). Often they will show up even with the meter around the conduit. The resulting voltage differences in grounds typically amount to 2 to 5 volts. It depends on load currents, neutral resistance, ground resistance, current paths, etc. Transients and noise of course include all those present on the load currents. In residential applications where several services, each with their own ground, are fed from a single transformer (also with its neutral grounded). Several amps typically flow in the parallel earth connections between houses, but this is irrelevant. The important thing to achieve is an equipotential earth environment around the particular house involved. Bob Johnson ITE Safety -Original Message- From: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org] On Behalf Of John Woodgate Sent: Saturday, October 12, 2002 12:53 PM To: emc-p...@majordomo.ieee.org Subject: Re: Ground potential differences I read in !emc-pstc that Bailey, Jeff jbai...@mysst.com wrote (in B115DFA26896D511BAB600105AA3493275EA3F@SSTMAIL) about 'Ground potential differences' on Fri, 11 Oct 2002: I am interested to know what the actual magnitude of ground differences may be from one end of a plant to another as well as where the numbers come from. It depends on what sort of equipment is present. Some things have very high leakage current, putting a lot of amps in total into ground conductors. Then, in old plants, there may be bad ground wiring that doesn't show up as a fault. Have they been calculated or actually measured? Both. Usually after the problem has been discovered by chance. I've measured 9 V over a distance of 20 m, but there are reports of much higher voltages. If shields are connected directly to chassis at each node of a network will there be an effect of equalizing the ground levels through the network or will enough current flow to melt the shield of the cable? Both are possible. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list attachment: Robert Johnson.vcf
CPE Telecom Equipment in Manitoba, Canada
Dear All, Has anyone heard of Canadian Manitoba provincial exemption regarding CPE Telecom Equipment supplied by a Class 2 transformer or power supply? This e-mail message may contain privileged or confidential information. If you are not the intended recipient, you may not disclose, use, disseminate, distribute, copy or rely upon this message or attachment in any way. If you received this e-mail message in error, please return by forwarding the message and its attachments to the sender. PETER S. MERGUERIAN Technical Director I.T.L. (Product Testing) Ltd. 26 Hacharoshet St., POB 211 Or Yehuda 60251, Israel Tel: + 972-(0)3-5339022 Fax: + 972-(0)3-5339019 Mobile: + 972-(0)54-838175 http://www.itl.co.il http://www.i-spec.com --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
Re: LED's and laser safety?
I read in !emc-pstc that richwo...@tycoint.com wrote (in 846BF526A205F8 4BA2B6045BBF7E9A6A04675859@flbocexu05) about 'LED's and laser safety?' on Mon, 14 Oct 2002: I sure would love to hear that argument. Just get a time machine and go back to the meeting of the IEC TC85 working group on the subject. (;-) Maybe someone on the group will let you read the Minutes; they are not in the public domain. It's a very sensible decision, IMHO. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
creepage et seq/spoof
In the interests of my own credibility on the board (if I have any?) I should wave the white flag of surrender and own up to having posted a nonsense message on Oct 9th in response to the genuine request for information about creepage limits. For some inexplicable reason my 'funny bone' was tickled and I wrote and posted the stuff about creepage and car batteries, copied below. I offer my apologies to board members who have been inconvenienced by this piece of tom foolery. In future I'll make it much clearer when sending a spoof post. As it happens the responses have been interesting, a testament to the intelligence and good humor of the board. Thank You Ted Rook copy of the spoof post: This is because when you double the voltage the power is proportional to a quarter of the current squared. In America the 120V power is at lower voltage but the current is twice as much and so the creepage is twice as well. Very high voltage circuits hardly creep at all whereas low voltages creep the most. That is why you should never join the two negative terminals when you jump start a car, the car battery charging circuits have so much creepage they can melt the battery. I though everybody knew that... end of copy --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
RTTE - receive only equipment
As far as I understand the RTTED, the directive also applies to radio receive-only equipment. But are we required to notify it for each member state within EU, if it use non-harmonized frequency bands ? Best regards Amund Westin, Oslo / Norway --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
RE: LED's and laser safety?
I sure would love to hear that argument. Richard Woods Sensormatic Electronics Tyco International -Original Message- From: Warren Birmingham [mailto:war...@comfortjets.com] Sent: Friday, October 11, 2002 6:06 PM To: emc-p...@ieee.org Subject: Re: LED's and laser safety? Gary, I was recently in conversation with UL about LEDs whereas I am now being told that UL has convinced the European counterparts that LEDs are no longer considered Class I Lasers and the requirements for them to be tested as such has been dropped. UL no longer treats them that way in their CB Reports. Warren Birmingham Epsilon-Mu Consultants (510) 793-4806 email: war...@epsilon-mu.com website: http://www.epsilon-mu.com On Thursday, Oct 10, 2002, at 08:53 US/Pacific, Gary McInturff wrote: IEC-825 has incorporated LED's into the safety standard but, from what I can tell, left a great deal of confusion. I typically deal with the 5 - 10 mcd devices and haven't been required to provide any IEC-825 conformity proof for the Western European test house. We may be jumping up to about 60 mcd and non-focused devices and I don't know where the standard starts to become concerned. I hate to buy the standard if it doesn't provide any clarity for these types of parts. Could you folks clue me in? Gary --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
RE: Testing for dry joints - :)
Scott asks .. So I give up - just what exactly is a dry joint? Dry joint: Electrical context: - A solder joint in which the electrical connection between two conductors has been poorly formed by the solder material; a consequence of incomplete formation or surfaces not properly wetted by the soldering material. Testing for these - as this group has shown - can be quite difficult. For more information on this type of dry joint, visit http://www.circuitsassembly.com Glastonbury Context: - Crushed weed or herbs of various descriptions usually rolled up in light paper ( tabloid newspapers make excellent wrappers) and used exactly like cigarettes. Testing for a dry joint should be done in secrecy as there are legal connotations associated with their use. In the interest of keeping this forum blameless, the quest for more information on this type of joint will be left to the reader. Rastafarian context: - Sensemelia dat bringz I an' I guud vibes man! Jah be prezd! Tess-teeng nat necessary. U av' some', u gretful, U pass it round, U a good frend, but wen U pass it around, keep it an de left 'and side. Night club context: - A night club that has run out of liquor. Testing for these is visual. They will usually have no revelers. Butcher's context: - Leg of lamb of the Halal variety, dried or well done . Testing for these is essential as 'succulent' might be the preferred end result of the culinary process. Surgeon's context: - Quality and effectiveness of lubrication following hip replacement. Testing inevitable. Homeless context: - Welcome refuge on rainy nights. Best regards - Chris -Original Message- From: Scott Douglas [SMTP:dougl...@naradnetworks.com] Sent: Friday, October 11, 2002 8:34 PM To: Chris Chileshe; emc-p...@majordomo.ieee.org Subject:Re: Testing for dry joints Chris, So I give up - just what exactly is a dry joint? Scott At 09:55 AM 10/9/2002 +0100, Chris Chileshe wrote: Hi Group, Probably not the appropriate forum but here goes anyway. A colleague is finding numerous problems with subtle dry joints (partial) between connectors and PCBs and is wondering if there is a way - short of new procedures in process control - that dry joints can be tested for? The specific problem is that the joints appear to be electrically sound to start with, meaning the units are getting through function test, but once exposed to endurance (lengthy) tests or worse still, actual practical use, the gremlins begin to show. The fault analysis almost invariably leads to a connector dry joint. The connectors are rated for 6A DC continuous. Any ideas how these can be picked up early or what measures you have in production to eradicate these problems? Regards - Chris Chileshe - Ultronics Ltd This e-mail has been scanned for all viruses by Star Internet. The service is powered by MessageLabs. For more information on a proactive anti-virus service working around the clock, around the globe, visit: http://www.star.net.uk --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list This e-mail has been scanned for all viruses by Star Internet. The service is powered by MessageLabs. For more information on a proactive anti-virus service working around the clock, around the globe, visit: http://www.star.net.uk This e-mail has been scanned for all viruses by Star Internet. The service is powered by MessageLabs. For more information on a proactive anti-virus service working around the clock, around the globe, visit: http://www.star.net.uk --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line:
RE: Filtered D Types.
Many thanks for all your help. Best regards, David Sproul.
RE: Record Retention
Randall, As Fred Borda pointed out, for Australia (both C-Tick and A-Tick) is 5 years for all documentation held in the product Compliance Folder starting from the time the device is no longer supplied in Australia. NOTE This may be different to being considered obsolete. In addition, if there is any modification introduced, even after the device is no longer available for purchase such as a repair involving an ECO (Engineering Change Order) which may impact compliance, the 5 years would commence from the time of the repair which introduced the ECO'd modification. Best regards, Kevin Richardson Stanimore Pty Limited Compliance Advice Solutions for Technology (including Australian Agent Services) (Legislation/Regulations/Standards) Ph: 02-4329-4070 (Int'l: +61-2-4329-4070) Fax: 02-4328-5639 (Int'l: +61-2-4328-5639) Mobile: 04-1224-1620 (Int'l: +61-4-1224-1620) Email:kevin.richard...@ieee.org This material (this message and the information contained in all attachments to this message) is confidential and/or privileged information and is intended only for the addressee/s named above. Any unauthorised dissemination, copying, use of or reliance upon this material by persons or entities other than the addressee/s named above is prohibited. If you receive this material in error, please notify Stanimore Pty Limited and destroy all copies (electronic and hardcopy) of this message and all attachments immediately. -Original Message- From: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of Flinders, Randall Sent: Friday, 11 October 2002 2:04 AM To: Emc-Pstc (E-mail) Subject: Record Retention Can anyone give me the record retention requirements for FCC Part 15, CE-Mark, and C-Tick certifications? How long must we keep the test reports once the product has gone obsolete? I believe this to be 2 years from the last date of manufacture for FCC but can't seem to find the section in the regs. Not sure where to even look for this information within the EMC directive or C-Tick framework. Any suggestions on where this information is located would be helpful. Thanks! Randy Flinders Electromagnetic Compatibility Engineer Emulex Corporation - We Network Storage 3535 Harbor Blvd. Costa Mesa, Ca. 92626 Direct: (714) 513-8012 Fax: (714) 513-5408 Email: randall.flind...@emulex.com mailto:randall.flind...@emulex.com Web: http://www.emulex.com --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
Filtered D types and ground potential
1.Filtered D can be obtained from Cinch who also have filter blocks that can be added as a retro-fit. ITT Cannon also supply connectors under their D*JK series. Many years ago as an apprentice, I needed to use more test equipment than sockets on the bench permitted. Placing a piece of test equipment on the bench behind me, it drew a spark as the bnc connection was made. The engineer I worked with just laughed and found an extension block. I suspect that the benches in that lab were fed from different phases from the mains input to the building. Regards, Neil Helsby ** This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error please notify the system manager. This footnote also confirms that this email message has been swept by MIMEsweeper for the presence of computer viruses. www.mimesweeper.com ** --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
RE: coax grounding of E3/DS3 in the EU
Look on the last version of ITU-T G.703. IN this the clause to isolate the RX side was deleted. Bye Paolo _ Paolo Gemma Siemens Mobile Communications S.p.A. PG MW ST EMC Safety 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 _ -Original Message- From: pfitzgib...@attbi.com [mailto:pfitzgib...@attbi.com] Sent: Monday, September 23, 2002 8:00 PM To: emc-p...@majordomo.ieee.org Subject: coax grounding of E3/DS3 in the EU Greetings all, I have a general question about E3/DS-3 in the EU. I have heard that it is no longer necessary to isolate one of the two Tx/Rx coax ports but can't find a definite answer. I'd like to know if I can directly tie both the TX and RX ports to chassis for intrabuilding only CO lines. This would make EMI/EMC much easier to pass and would get rid of the special AC coupling that would otherwise be necessary. The only reason that I could ever understand for the DC isolation requirements that used to be in place was to prevent ground connections in IBN CO's or to eliminate current on the shields due to differences in earth potential between buildings. As neither of these really apply, I really don't see why it should still be necessary to provide the DC isolation (I have only intrabuilding lines and most CO's are now CBN installations). Does anyone know what the current status on this is? Thanks, Patrick --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
