Re: Wiring under raised floors
ted.eck...@apcc.com wrote: Is it permissible to place electrical receptacles under the raised floor of a computer room? Can power cords pass through openings in the raised floor or do all power connections need to be in conduit? I have received two opinions; one stating that receptacles must be accessible above floor level and the other stating that receptacles can be placed below the floor. The United States National Electrical Code is a bit vague on the subject, although Article 645-5 (d) (2) seems to imply that conduit is only required up to the receptacle. I can find no references to raised floor installations in the Canadian Electrical Code or BS 7671, IEE Wiring Regulations. Ted, In order that your company NEVER have any problems with this issue ever, you will have to follow NEC 645-5 to the letter. Ultimately, it's up to the interpretation of the local inspector. Having been called on the rug about this very issue from just one customer within the past year, my *suggestion* is: Do NOT put ANY power cords under a raised floor no matter if it's a plenum issue or not and no matter how long or short that power cord may be - none. Unless of course you can procure the style power cord required by the standard. And good luck with that. - Regards, Doug McKean --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Re: compactPCI bus
Fleury, Bill wrote: Judging from the number of responses (0) I got to my question about EMI problems from compactPCI backplanes I am assumiong that either no one uses cPCI backplanes or I'm the only one that has experienced problems when testing in this environment. I didn't think that ever happened in this group. I'll repost this just in case some of you didn't get the last one. This is a question regarding systems which use CompactPCI bus architecture. On a cPCI backplane the PCI clock is routed to every slot on the backplane with up to 7 peripheral slots possible on a normal backplane. My question is this: With the cPCI specification calling out specific trace lengths for clock traces on both the backplane itself and on peripheral cards, have other people experienced any unique EMI problems in trying to meet the design constraints associated with this synchronous bus; especially where there are unpopulated slots on the backplane? Please feel free to respond privately if the question is unclear. I wasn't sure if it was worded properly. I didn't catch your former post. As the PCI bus is a reflective based bus, in my opinion, the PCI bus is one of the worst bus constructions ever imagined. I've had the pleasant experience of trying to cope with 132 MHz all over the damn place. For a 33 MHz based bus, yes, I'm talking 4th harmonics. Harmonics can abound above that was well. Remember that odd harmonics are only produced by a perfect square wave. Any asymmetry to a square wave starts including even harmonics. Add in some fast edge rates adding to a bandwidth out to approx (0.35/Tr) depending upon who you talk to and you've got a potential rats nest. Grounding the face plates of interface cards to the chassis is especially tricky. If your box is using regular style interface card sheet metal construction that you would find on the back of any regular PC, then you will have to make special care to inspect the vertical rails that are supposed to be in contact with the face plates. I know that's a mouthful, but I hope you understand what I'm trying to say. I've had to deal with a weird slot effect under some circumstances with such a construction. A voltage differential across the slot causes the slot effect to radiate onto the cable making the cable *appear* to be culprit. In my case, even though the cable was the *radiator*, it's not the source of the problem. By simply trying to add a ferrite AND discovering that the ferrite does little to solve the problem, therein lies the hint that this slot effect is, well, in effect and doing fine to make your life difficult. Anywhere from about 6 to 10 dB of attenuation can be had with a gasket. I can only reiterate and fully agree with Mr. Cortland's comment regarding the grounding provided by the chassis slot. Bottom line, make sure your signal integrity guys know what they're doing from an emi viewpoint before you even start and make sure to gain a close association with some unsung heroes in the mechanical department. You just may be needing them. There. That's a total of about $10,000 worth of advice, experience, theory, pain, and solution. I expect my check in the mail by tomorrow ... (just joking ...) Regards and have fun, Doug McKean --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Re: Component Qualification
Tony: I have sold these systems and also used them and they are good for graphing a profile of a scanned board and giving the field intensity vs postion over the board area. You can quickly find trouble spots using the computer interface. Ralph Cameron - Original Message - From: Tony J. O'Hara tonyoh...@compuserve.com To: Koh Nai Ghee koh...@cyberway.com.sg Cc: EMC-PSTC emc-p...@majordomo.ieee.org Sent: Wednesday, September 20, 2000 4:42 PM Subject: Re: Component Qualification You may want to look at using a PCB Electromagnetic Scanning System! One of the advertised uses for these test devices is for quickly comparing EMC performance when component changes are made etc.! I believe there are 4 different manufacturers who make these devices. The one that I'm just starting to learn about is made by EMSCAN in Canada. Their web is www.emscan.com Maybe someone who has uses one of these scanners can provide an experienced viewpoint? Regards Tony Colorado --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Data on Power Lines
Dear All, For a unit that transmits and/or recieves data over mains power lines, is UL1950/IEC950 the correct standard? Peter Merguerian Managing Director Product Testing Division I.T.L. (Product Testing) Ltd. Hacharoshet 26, POB 211 Or Yehuda 60251, Israel Tel: 972-3-5339022 Fax: 972-3-5339019 e-mail: pmerguer...@itl.co.il website: http://www.itl.co.il TO LEARN ABOUT AUSTRALIAN AND NEW ZEALAND REQUIREMENTS, CONTACT ME AT THE EARLIEST STAGES OF YOUR DESIGN; REQUIREMENTS CAN BE TRICKY! --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Data on Power Lines
Peter, The Scope (1.1) of IEC 60950 is for mains or battery powered ITE. If the product is mains/battery powered, then IEC 60950 could apply, regardless of how it performs it's ITE function. However, there may also be other applicable standards. George -- Forwarded by George Alspaugh/Lex/Lexmark on 09/21/2000 07:34 AM --- pmerguerian%itl.co...@interlock.lexmark.com on 09/21/2000 06:52:43 AM Please respond to pmerguerian%itl.co...@interlock.lexmark.com To: emc-pstc%majordomo.ieee@interlock.lexmark.com cc:(bcc: George Alspaugh/Lex/Lexmark) Subject: Data on Power Lines Dear All, For a unit that transmits and/or recieves data over mains power lines, is UL1950/IEC950 the correct standard? Peter Merguerian Managing Director Product Testing Division I.T.L. (Product Testing) Ltd. Hacharoshet 26, POB 211 Or Yehuda 60251, Israel Tel: 972-3-5339022 Fax: 972-3-5339019 e-mail: pmerguer...@itl.co.il website: http://www.itl.co.il --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: DSSS document on FCC website?
Hi Paul, Try FCC 97-114 Appendix C. It is entitled Guidance on Measurements for Direct Sequence Spread Spectrum Systems. I think this is what you're after. Good Luck! ~ Sam Wismer RF Approvals Engineer LXE, Inc. (770) 447-4224 Ext. 3654 Visit Our Website at: http://www.lxe.com -Original Message- From: Paul Slavens [mailto:paul_slav...@hotmail.com] Sent: Wednesday, September 20, 2000 5:22 PM To: emc-p...@ieee.org Subject: DSSS document on FCC website? Dear Group, I was able find DA 00-705 - Filing and Measurement Guidelines for Frequency Hopping Spread Spectrum Systems on the FCC web site. I am pretty sure a comparable document exists for Direct Sequence Spread Spectrum Systems, however, I was unable to find it. I sure would appreciate it if any of you fine persons could point me in the right direction. Regards Paul G. Slavens Acme Testing _ Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com. Share information about yourself, create your own public profile at http://profiles.msn.com. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: Component Qualification
Wait a minute! Buying a board scanning system to evaluate different vendors for ferrites and oscillators? My company doesn't have that kind of money to throw around. These systems can cost 10's of thousands of dollars. Ferrite beads cost about a dime for a dump truck load. If it costs $10,000 to evaluate a second source for ferrites, I 'll stick with the ferrites I have. I'd like to offer a lower cost alternative. Koh Nai asked about what specifications were important for qualifying alternate sources for ferrites and oscillators. When it comes to ferrites, I look at three things: I look at the PCB footprint (it won't work if it won't fit). I look at the impedance curve and the current capacity. If all three of these specifications are equal or better than what I need, I accept them. I don't even consider re-testing for emissions if I have checked these three specifications. Alternate sources for ferrites can be qualified for the cost of reading a spec sheet. Oscillators are a different story. When one of my digital design colleagues wants to change oscillators. They consider its PCB footprint, the output frequency, its ambient stability, its temperature stability and its load driving capability. If it meets their needs; then I take a circuitboard with the existing oscillator and run a near field probe over it near the oscillator until if find a location of maximum near field emissions. (If you really are strapped for cash, you can make your own near field probe.) I write down the exact position and orientation of the near field probe and I either print out or write down the spectrum analyzer readings. I then put the new oscillator on the exact same board and repeat the experiment. If the measurements are close (within a dB or two) I don't worry. If the measurements are more than 4 dB higher, then I look further. Then I consider: testing the whole unit with the new oscillator with my antenna set up 1 meter away in-house, or re-testing the unit for emissions at an OATS, or not using the new oscillator. ONE WARNING: if the new oscillator is at a different frequency, then the method above WILL NOT yield any useful results. One thing that we have done with new designs is to put a 1206 surface mount PCB footprint in line with the oscillator output. We start our testing with a 0 ohm resistor. If we run into problems, we can put either a ferrite bead or higher value resistor in this position to cool off the oscillator. This has worked well with oscillators under 100MHz. I don't know if it will work for faster oscillator. I know that there are problems with using near field probes to make such correlations, however using a board scanning device would cost much more than a near field probe and still only be measuring near fields. Even so, if I had the budget, I'd love to try one out. To me, the real method of doing this starts with the initial testing of your product. I try to get more than a 5dB margin during the initial testing. With these margins, I don't need to worry so much about component differences. I know that this is sometimes not possible. I have sacrificed margins in order to get a product's testing done and released (I don't get paid if we don't ship.) The problem is, without margins, I need to worry more about component differences. Another point to remember is that EN 55022 and other emissions standards go by the 80 % rule. A product passes if we are confident that 80% of the units that we ship meet the emissions requirements. Anybody who wants to dispute whether your units pass or not is REQUIRED to test up to 7 samples in order to get enough data to use statistical methods to compute the confidence factor. One failing unit does not equal a guilty verdict. (Of course, if one unit is failing by 20dB, that's a problem.) The people at CISPR put this slack into the limits to allow for slight component differences and measurement uncertainty. They allowed us the slack, but it is our responsibility to use it with common sense. These are my two cents worth and definitely don't reflect the opinions of my employer. (Why would they need me if I thought the same way they do?) Have a great day! Chris Maxwell, Design Engineer GN Nettest Optical Division 6 Rhoads Drive, Building 4 Utica, NY 13502 PH: 315-797-4449 FAX: 315-797-8024 EMAIL: chr...@gnlp.com -Original Message- From: Ralph Cameron [SMTP:ral...@igs.net] Sent: Wednesday, September 20, 2000 11:16 PM To: Tony J. O'Hara; Koh Nai Ghee Cc: EMC-PSTC Subject: Re: Component Qualification Tony: I have sold these systems and also used them and they are good for graphing a profile of a scanned board and giving the field intensity vs postion over the board area. You can quickly find trouble spots using the computer interface. Ralph Cameron - Original Message - From: Tony J. O'Hara tonyoh...@compuserve.com To: Koh Nai Ghee koh...@cyberway.com.sg Cc:
Re:Protection or Control?
Luiz, The applicable standards would depend on the product, e.g. whether it is a laser printer (ITE) with the necessary fuser, or a hair dryer, or a coffee maker. However, it is my understanding that most products involving heating devices would require two components, i.e. a temperature controlling device (thermostat) and a fail-safe device (thermal fuse). ITE standards require safety after any single fault. If the control device fails in a shorted mode, what prevents the heating element from melting the product and potentially starting an external fire? At least for ITE, a bimetal thermostat would not also serve as the protection device unless there is no possible way to fail in the shorted mode. George Forwarded by George Alspaugh/Lex/Lexmark on 09/21/2000 08:45 AM --- jim_bacher%mail.monarch@interlock.lexmark.com on 09/21/2000 10:46:00 AM Please respond to jim_bacher%mail.monarch@interlock.lexmark.com To: luizbonilla%ig.com...@interlock.lexmark.com, emc-pstc%majordomo.ieee@interlock.lexmark.com cc:(bcc: George Alspaugh/Lex/Lexmark) Subject: Re:Protection or Control? forwarding for luizboni...@ig.com.br Reply Separator Subject:Protection or Control? Author: Luiz Claudio luizboni...@ig.com.br List-Post: emc-pstc@listserv.ieee.org Date: 9/20/00 9:59 PM I have a question to those who are familiar with the safety requirements established electrical appliance standards. A bimetal thermostat is usuallly used to control the temperature of a certain ambient within certain limits. Can it also be considered as a protection device? I'm not going to give my oppinion to avoid any possibility of biased answers. But, please, give your oppinion. If you have a reference publication which I could use as a reference for a work to be presented, please include it in your answer. If not, no problem. Just give your oppinion. Please answer this message to my personal email address: luizboni...@ig.com.br Thanks a lot, Luiz --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: DSSS document on FCC website?
Paul, the DSSS version of the document was published as Appendix C to the original final rule-making in FCC ET Docket 96-8. EdB -Original Message- From: Paul Slavens [mailto:paul_slav...@hotmail.com] Sent: Wednesday, September 20, 2000 4:22 PM To: emc-p...@ieee.org Subject: DSSS document on FCC website? Dear Group, I was able find DA 00-705 - Filing and Measurement Guidelines for Frequency Hopping Spread Spectrum Systems on the FCC web site. I am pretty sure a comparable document exists for Direct Sequence Spread Spectrum Systems, however, I was unable to find it. I sure would appreciate it if any of you fine persons could point me in the right direction. Regards Paul G. Slavens Acme Testing _ Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com. Share information about yourself, create your own public profile at http://profiles.msn.com. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: Protection or Control?
Depends. If the thermal cut out fails, can the product reach unsafe temperatures? If yes then it is a protective device, if no then it isn't. A standard that covers thermal cut outs is IEC60730. Thermal links are covered by IEC60691. Regards Chris Colgan EMC Safety TAG McLaren Audio Ltd mailto:chris.col...@tagmclarenaudio.com -Original Message- From: jim_bac...@mail.monarch.com [SMTP:jim_bac...@mail.monarch.com] Sent: 21 September 2000 15:46 To: Luiz Claudio; 'emc-pstc' Subject: Re:Protection or Control? forwarding for luizboni...@ig.com.br Reply Separator Subject:Protection or Control? Author: Luiz Claudio luizboni...@ig.com.br Date: 9/20/00 9:59 PM I have a question to those who are familiar with the safety requirements established electrical appliance standards. A bimetal thermostat is usuallly used to control the temperature of a certain ambient within certain limits. Can it also be considered as a protection device? I'm not going to give my oppinion to avoid any possibility of biased answers. But, please, give your oppinion. If you have a reference publication which I could use as a reference for a work to be presented, please include it in your answer. If not, no problem. Just give your oppinion. Please answer this message to my personal email address: luizboni...@ig.com.br Thanks a lot, Luiz --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org = Authorised on 09/21/00 at 14:03:31; code 37f48bf3385FBE9E. ** Please visit us at www.tagmclarenaudio.com ** The contents of this E-mail are confidential and for the exclusive use of the intended recipient. If you receive this E-mail in error, please delete it from your system immediately and notify us either by E-mail, telephone or fax. You should not copy, forward or otherwise disclose the content of the E-mail. TAG McLaren Audio Ltd The Summit, 11 Latham Road Huntingdon, Cambs, PE29 6ZU Telephone : 01480 415600 (+44 1480 415600) Facsimile : 01480 52159 (+44 1480 52159) ** Please visit us at www.tagmclarenaudio.com ** --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Re: Component Qualification
Chris, Don't get me wrong. I didn't read the full text of the application and merely supported the utility of the EMSCAN system. If you know of sources where you cn get ferrites, specifically ferrite toroids for a dime a dump truck, I'd be interested. In the past two years my costs for them have more than tripled as the mfr now uses dealers who have minu\imum quantities which are out of sight for the small vendor. With the heavier weights , shipping costs skyrocket. I like your methods of determining ferrite application and how to look for hpt spots. My opinions are my own since I work for me. regards Ralph Cameron EMC Consultant and Suppression of Consumer Elecronics (after sale). - Original Message - From: Maxwell, Chris chr...@gnlp.com To: 'Ralph Cameron' ral...@igs.net; Tony J. O'Hara tonyoh...@compuserve.com; Koh Nai Ghee koh...@cyberway.com.sg Cc: EMC-PSTC emc-p...@majordomo.ieee.org Sent: Thursday, September 21, 2000 7:58 AM Subject: RE: Component Qualification Wait a minute! Buying a board scanning system to evaluate different vendors for ferrites and oscillators? My company doesn't have that kind of money to throw around. These systems can cost 10's of thousands of dollars. Ferrite beads cost about a dime for a dump truck load. If it costs $10,000 to evaluate a second source for ferrites, I 'll stick with the ferrites I have. I'd like to offer a lower cost alternative. Koh Nai asked about what specifications were important for qualifying alternate sources for ferrites and oscillators. When it comes to ferrites, I look at three things: I look at the PCB footprint (it won't work if it won't fit). I look at the impedance curve and the current capacity. If all three of these specifications are equal or better than what I need, I accept them. I don't even consider re-testing for emissions if I have checked these three specifications. Alternate sources for ferrites can be qualified for the cost of reading a spec sheet. Oscillators are a different story. When one of my digital design colleagues wants to change oscillators. They consider its PCB footprint, the output frequency, its ambient stability, its temperature stability and its load driving capability. If it meets their needs; then I take a circuitboard with the existing oscillator and run a near field probe over it near the oscillator until if find a location of maximum near field emissions. (If you really are strapped for cash, you can make your own near field probe.) I write down the exact position and orientation of the near field probe and I either print out or write down the spectrum analyzer readings. I then put the new oscillator on the exact same board and repeat the experiment. If the measurements are close (within a dB or two) I don't worry. If the measurements are more than 4 dB higher, then I look further. Then I consider: testing the whole unit with the new oscillator with my antenna set up 1 meter away in-house, or re-testing the unit for emissions at an OATS, or not using the new oscillator. ONE WARNING: if the new oscillator is at a different frequency, then the method above WILL NOT yield any useful results. One thing that we have done with new designs is to put a 1206 surface mount PCB footprint in line with the oscillator output. We start our testing with a 0 ohm resistor. If we run into problems, we can put either a ferrite bead or higher value resistor in this position to cool off the oscillator. This has worked well with oscillators under 100MHz. I don't know if it will work for faster oscillator. I know that there are problems with using near field probes to make such correlations, however using a board scanning device would cost much more than a near field probe and still only be measuring near fields. Even so, if I had the budget, I'd love to try one out. To me, the real method of doing this starts with the initial testing of your product. I try to get more than a 5dB margin during the initial testing. With these margins, I don't need to worry so much about component differences. I know that this is sometimes not possible. I have sacrificed margins in order to get a product's testing done and released (I don't get paid if we don't ship.) The problem is, without margins, I need to worry more about component differences. Another point to remember is that EN 55022 and other emissions standards go by the 80 % rule. A product passes if we are confident that 80% of the units that we ship meet the emissions requirements. Anybody who wants to dispute whether your units pass or not is REQUIRED to test up to 7 samples in order to get enough data to use statistical methods to compute the confidence factor. One failing unit does not equal a guilty verdict. (Of course, if one unit is failing by 20dB, that's a problem.) The people at CISPR put this slack into the limits to allow for slight component differences and
Sept. 15, 2000 Conformity-Update Now Available
Conformity-Update for the week ending Sept. 15, 2000 is now available at: http://www.conformity-update.com --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: Protection or Control?
Luiz - Bimetal switched are used as manual and automatic reset thermal protectors in electric motors, transformers. Very common and has been for many years. Regards, Peter L. Tarver, PE ptar...@nortelnetworks.com -Original Message- From: jim_bac...@mail.monarch.com [mailto:jim_bac...@mail.monarch.com] Sent: Thursday, September 21, 2000 3:46 PM To: Luiz Claudio; 'emc-pstc' Subject: Re:Protection or Control? forwarding for luizboni...@ig.com.br Reply Separator Subject:Protection or Control? Author: Luiz Claudio luizboni...@ig.com.br List-Post: emc-pstc@listserv.ieee.org Date: 9/20/00 9:59 PM I have a question to those who are familiar with the safety requirements established electrical appliance standards. A bimetal thermostat is usuallly used to control the temperature of a certain ambient within certain limits. Can it also be considered as a protection device? I'm not going to give my oppinion to avoid any possibility of biased answers. But, please, give your oppinion. If you have a reference publication which I could use as a reference for a work to be presented, please include it in your answer. If not, no problem. Just give your oppinion. Please answer this message to my personal email address: luizboni...@ig.com.br Thanks a lot, Luiz
Re:Protection or Control?
Many of the cheap thermal circuit breakers listed under UL 1077 (Supplementary Protectors For Use In Electronic Equipment) are nothing more than a bimetallic strip. Current is carried through the bimetallic strip itself. As the current increases, the strip heats up and eventually opens the contacts. The circuit breakers do have a spring loaded barrier that moves between the contacts after they open. This prevents the circuit breaker from resetting automatically and prevents arcing. For limiting current, a recognized circuit breaker should be used. In addition, UL 1950 section 1.7.13 refers to thermostats. The standard allows the thermostat to limit temperature, but they should not be used for other purposes. Ted Eckert Regulatory Compliance Engineer American Power Conversion Corporation ted.eck...@apcc.com The items contained in this e-mail reflect the personal opinions of the writer and are only provided for the assistance of the reader. The writer is not speaking in an official capacity for APC nor representing APC's official position on any matter. Jim_Bacher@mail.m onarch.com (Jim To: Luiz Claudio luizboni...@ig.com.br, 'emc-pstc' Bacher) emc-p...@majordomo.ieee.org Sent by: cc: owner-emc-pstc@ieSubject: Re:Protection or Control? ee.org 09/21/00 09:46 AM Please respond to Jim_Bacher forwarding for luizboni...@ig.com.br Reply Separator Subject:Protection or Control? Author: Luiz Claudio luizboni...@ig.com.br List-Post: emc-pstc@listserv.ieee.org Date: 9/20/00 9:59 PM I have a question to those who are familiar with the safety requirements established electrical appliance standards. A bimetal thermostat is usuallly used to control the temperature of a certain ambient within certain limits. Can it also be considered as a protection device? I'm not going to give my oppinion to avoid any possibility of biased answers. But, please, give your oppinion. If you have a reference publication which I could use as a reference for a work to be presented, please include it in your answer. If not, no problem. Just give your oppinion. Please answer this message to my personal email address: luizboni...@ig.com.br Thanks a lot, Luiz --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
ESD Opportunities
I am doing a graduate research project on the ESD opportunities that exist in the telecom market, specifically cell phones and laptops that have LCD's which are affected by ESD. Is this a market to look into, and what are the requirements and trends that you see going on? What materials or solutions are currently being used to address ESD problems in these systems, and are they they working? Lastly, is ESD a factor that is considered when designing EMI shielding solutions? I would appreciate any insight you may have. Thanks! kl _ Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com. Share information about yourself, create your own public profile at http://profiles.msn.com. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Re:Protection or Control?
forwarding for luizboni...@ig.com.br Reply Separator Subject:Protection or Control? Author: Luiz Claudio luizboni...@ig.com.br List-Post: emc-pstc@listserv.ieee.org Date: 9/20/00 9:59 PM I have a question to those who are familiar with the safety requirements established electrical appliance standards. A bimetal thermostat is usuallly used to control the temperature of a certain ambient within certain limits. Can it also be considered as a protection device? I'm not going to give my oppinion to avoid any possibility of biased answers. But, please, give your oppinion. If you have a reference publication which I could use as a reference for a work to be presented, please include it in your answer. If not, no problem. Just give your oppinion. Please answer this message to my personal email address: luizboni...@ig.com.br Thanks a lot, Luiz --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Re[2]:Protection or Control?
I know that most safety standards require the equipment to remain safe under single fault conditions. In this case the single fault I would consider would be that of failure of the thermostat (i.e short circuited) The first thing to consider would be, can the failure of this device allow the temperature to reach a hazardous level taking into account, touch temperatures, thermal limits on other components in the vicinity (electrical and mechanical) and possibility of ignition. If the answer is yes then this component is safety critical as its failure can lead to an unsafe condition. If this is so then a protection measure would have to be taken to ensure that the equipment remained 'safe' under single fault conditions. Now you have one component for control and one component for protection, the protective device only operating when the equipment is out of control. In a previous job I had to run a test on some equipment that included a heating element. as a result of fault testing the control circuit the element became so hot its metal fins melted and dripped into the bottom of the enclosure! The problem was resolved with a series thermal cutout mounted on the element body. Hope this is helpful... Regards. Reply Separator Subject:Re:Protection or Control? Author: jim_bac...@mail.monarch.com List-Post: emc-pstc@listserv.ieee.org Date: 21/09/00 15:46 forwarding for luizboni...@ig.com.br Reply Separator Subject:Protection or Control? Author: Luiz Claudio luizboni...@ig.com.br List-Post: emc-pstc@listserv.ieee.org Date: 9/20/00 9:59 PM I have a question to those who are familiar with the safety requirements established electrical appliance standards. A bimetal thermostat is usuallly used to control the temperature of a certain ambient within certain limits. Can it also be considered as a protection device? I'm not going to give my oppinion to avoid any possibility of biased answers. But, please, give your oppinion. If you have a reference publication which I could use as a reference for a work to be presented, please include it in your answer. If not, no problem. Just give your oppinion. Please answer this message to my personal email address: luizboni...@ig.com.br Thanks a lot, Luiz --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: Brazilian requirements
I recently completed a Brazilian compliance effort on a telecom device. It was handled via a consultant with expertise in South American regulatory requirements. I was required to supply copies of existing test reports ( Part 68, Part 15, applicable CTRs, and CB Scheme), electronic photos, and a description of the device and it's normal functionality. No test samples or testing was required. The information was reviewed and processed, and the end result was an ANATEL approval certificate. If you'd like contact information for the Consultant I used, feel free to e-mail me. At 05:04 PM 9/20/00 -0400, Clement Dave-LDC009 wrote: For Terminal Equipment the generic requirments are; Federal Official Gazette - Ordance No. 322 - Net No. 001/92 There is also a test procedure - No.225-540-514 Test Procedures for Data Communications Equipment for Transmission Nominal Speed Up yo 28800 Bits/sec These are published in Portuguese and you will need to have them translated. Make sure you get a technical translator. We had a requirement that got translated incorrectly that placed an out of band requirement on voice band signals. David Clement Motorola Inc. Global Homologation Engineering 20 Cabot Blvd. Mansfield, MA 02048 P: 508-261-4389 F: 508-261-4777 E: mailto:dave.clem...@motorola.com Pager: Numeric: 978-545-5452 Alpha: mailto:6178020099.0705...@pagenet.net -Original Message- From: jradom...@clare.com [mailto:jradom...@clare.com] Sent: Wednesday, September 20, 2000 1:43 PM To: emc-p...@ieee.org Subject: Brazilian requirements Group, Could you advise me on the Brazilian telecom requirements for interfaces to be connected to the analog PSTN? I was not able to find any information on this subject in English. Thank you in advance. John Radomski Product Compliance Engineer Clare Corp. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Linehan Hardware Engineer VGSBU Cisco Systems Inc. 300 Apollo Drive Chelmsford, MA. 01824 Phone: (978) 244-5716 Fax:(978) 244-5908 --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Protection or Control?
Ted's note said: In addition, UL 1950 section 1.7.13 refers to thermostats. The standard allows the thermostat to limit temperature, but they should not be used for other purposes. Actually, section 1.7.13 pertains only to marking and instructions related to adjustable thermostats. It does not address the use or testing of such devices. Annex K does address the test requirements for thermal controls. George --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Susceptibility of USP ports to Industrial Environment test levels.
Hello: RE:Susceptibility of USB ports to Industrial Environment test levels. Does anyone have experience to the susceptibility of commercially available PC's and mother boards at the industrial test levels? For example RS232 and USB ports with the 1000 V EFT, 10V/M RF radiated, and 10V RF conducted immunity tests. (EN 61000-4-4, -4-6 etc.) Do they fold under those levels? I always protect them when using them as support equipment. Am I over cautious? Regards, Terry Meck --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Re:FW: RE: Brazilian requirements
forwarding for ncc1...@nccrc.com Reply Separator Subject:FW: RE: Brazilian requirements Author: Net Connection Corp ncc1...@nccrc.com List-Post: emc-pstc@listserv.ieee.org Date: 9/21/00 9:19 AM TO: John Radomski Product Compliance Engineer Clare Corp. David Clement Motorola Inc. Global Homologation Engineering FROM: Richard L. Swarz Net Connection Corp Hi John and David, Jim was kind enough to forward these e-mails. We look forward to address any questions on Brazil and all other countries South of the US Border. David, the regulation that you site may be of interest, if you plan to test in Brazil. We have been successful in avoiding IN Country Testing by utilizing our Licensed engineers and Test Reports based primarily on European Standards. Brazil's Standards are currently from the former Telebras Until 1998 the only phone provider in Brazil. There are alternative Brazilian Standards that may work equally well in determining if the Product meets Brazil's regulations. Awaiting your e-mail / call. Best regards, Richard 310 821-0700 310 574-9540 FAX ncc1...@nccrc.com -Original Message- From: Net Connection Corp [mailto:ncc1...@nccrc.com] Sent: Thursday, September 21, 2000 9:07 AM To: 'James Linehan' Subject: RE: RE: Brazilian requirements Hi Jim, Many thanks, your kindness is greatly appreciated. Best regards, Richard 310 821-0700 310 574-9540 FAX ncc1...@nccrc.com -Original Message- From: James Linehan [mailto:jline...@cisco.com] Sent: Thursday, September 21, 2000 11:37 AM To: ncc1...@nccrc.com Subject: Fwd: RE: Brazilian requirements Richard, FYI There may be some business coming your way, I've forwarded your contact information to each of the gentlemen noted below. From: Dave Clark david.cl...@spikebroadband.net To: 'James Linehan' jline...@cisco.com Subject: RE: Brazilian requirements Date: Thu, 21 Sep 2000 11:18:30 -0400 X-Mailer: Internet Mail Service (5.5.2650.21) James, I am very interested in the consultant you used. Please forward me their contact info. Dave -Original Message- From: James Linehan [mailto:jline...@cisco.com] Sent: Thursday, September 21, 2000 12:36 PM To: Clement Dave-LDC009; 'jradom...@clare.com'; emc-p...@ieee.org Subject: RE: Brazilian requirements I recently completed a Brazilian compliance effort on a telecom device. It was handled via a consultant with expertise in South American regulatory requirements. I was required to supply copies of existing test reports ( Part 68, Part 15, applicable CTRs, and CB Scheme), electronic photos, and a description of the device and it's normal functionality. No test samples or testing was required. The information was reviewed and processed, and the end result was an ANATEL approval certificate. If you'd like contact information for the Consultant I used, feel free to e-mail me. At 05:04 PM 9/20/00 -0400, Clement Dave-LDC009 wrote: For Terminal Equipment the generic requirments are; Federal Official Gazette - Ordance No. 322 - Net No. 001/92 There is also a test procedure - No.225-540-514 Test Procedures for Data Communications Equipment for Transmission Nominal Speed Up yo 28800 Bits/sec These are published in Portuguese and you will need to have them translated. Make sure you get a technical translator. We had a requirement that got translated incorrectly that placed an out of band requirement on voice band signals. David Clement Motorola Inc. Global Homologation Engineering 20 Cabot Blvd. Mansfield, MA 02048 P: 508-261-4389 F: 508-261-4777 E: mailto:dave.clem...@motorola.com Pager: Numeric: 978-545-5452 Alpha: mailto:6178020099.0705...@pagenet.net -Original Message- From: jradom...@clare.com [mailto:jradom...@clare.com] Sent: Wednesday, September 20, 2000 1:43 PM To: emc-p...@ieee.org Subject: Brazilian requirements Group, Could you advise me on the Brazilian telecom requirements for interfaces to be connected to the analog PSTN? I was not able to find any information on this subject in English. Thank you in advance. John Radomski Product Compliance Engineer Clare Corp. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org
Argentina IRAM
Hello All.. Does anyone have a URL for the IRAM homepage .. in English ?? Thanks, George
Re: Argentina IRAM
Hi George, There is a link on the Safety Link (to IRAM). However, I expect there is no English language link. When you are in Argentina - speak Argentine ;-) An alternative: Try AltaVista's translator at: babelfish.altavista.com and point it at IRAM's URLs. The translation, although not perfect, will give you a good idea of what's up, down there. Regards, Art Michael Int'l Product Safety News A.E. Michael, Editor 166 Congdon St. East P.O. Box 1561 Middletown CT 06457 U.S.A. Phone : (860) 344-1651 Fax: (860) 346-9066 Email : i...@connix.com Website: http://www.safetylink.com ISSN : 1040-7529 -- On Thu, 21 Sep 2000, George Sparacino wrote: Hello All.. Does anyone have a URL for the IRAM homepage .. in English ?? Thanks, George --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: A14 to EN61000-3-2 Did it pass?
Yes prA14 did pass I have been reliably informed. It will be interesting to see when it is going to be published in the OJEC. John Cronin From: wo...@sensormatic.com Reply-To: wo...@sensormatic.com To: emc-p...@majordomo.ieee.org Subject: RE: A14 to EN61000-3-2 Did it pass? Date: Mon, 18 Sep 2000 14:57:11 -0400 A14 moves all equipment out of Class D except for personal computers and televisions, and the 75 lower limit remains. However, the dop is scheduled to be after 2001-01-01. Until then, our Notified Body (SEE) is accepting prA14 for use in a TCF. Richard Woods -- From: Jim Eichner [SMTP:jim.eich...@xantrex.com] Sent: Monday, September 18, 2000 2:30 PM To: 'EMC-PSTC - forum' Subject: RE: A14 to EN61000-3-2 Did it pass? Follow-on question: Just to be really sure I haven't missed anything, A14 is a clarification of requirements and test methods and does nothing to postpone the drop dead date for this standard, right? Thanks, Jim -Original Message- From: Tolbert, J. Joe x1105 [mailto:jtolb...@genicom.com] Sent: Monday, September 18, 2000 10:34 AM To: 'emc-p...@ieee.org' Subject: A14 to EN61000-3-2 Did it pass? Was Amendment 14 accepted? I understood that it was suppose to be voted on last Friday. Joe --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org _ Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com. Share information about yourself, create your own public profile at http://profiles.msn.com. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Re: Argentina IRAM
George, Their web site is : www.iram.com.ar Thanks Kevin --- George Sparacino george.sparac...@bostonacoustics.com wrote: Hello All.. Does anyone have a URL for the IRAM homepage .. in English ?? Thanks, George __ Do You Yahoo!? Send instant messages get email alerts with Yahoo! Messenger. http://im.yahoo.com/ --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
