Re: Ethernet connector shield decoupling capacitor
Jim, There is absolutely no reason why the 250V caps would be required between the connector shell and the PCB digital GND, and it is especially true since you are using UTP. I could foresee some trying to argue it in case of STP, which I do not support either, but I am not going there now. Lightning surge is of no concern here, because Ethernet is rated 1500Vrms (IEEE spec), and is guaranteed to hold any common mode surge up to 2121V pk. If you zap any Ethernet transformer with common mode surge up to that level, you will get very low-level transients through the transformer. Differential-moode surge test wold be different, as some folks who deal with GR1089 have learned, but that requirement is now gone away for Ethernet, with the latest revision of GR1089. If you zap a port above the isolation-level that is required/speciified, the cap is not going to help in any way, because the transformer that is in prallel to the cap may get punctured anyways - no guuarantee for anything above 2121V pk. Neven -- Original message -- From: "Jim Eichner" > We're being hit with a requirement that I don't understand. > > We are using a shielded Ethernet connector that contains the typical 2kV > cap from the common point of the 75 ohm resistors to the shield. This > is used on the output of an off-the-shelf Ethernet transceiver module, > and the mfr of that module is telling us we need to connect the > connector shield to their digital ground through a 1nF 250V Y-cap, not > directly. > > 1. Why not directly connect the shield to digital ground? > > 2. Why would a Y-cap be required? The cap would be joining two parts of > the same circuit, so it would not be across an isolation boundary. I > can't think of a reason to require either the 250V! rating or the Y > rating. > > Any thoughts anyone? > > Thanks, > > Jim Eichner, P.Eng. > Manager - Compliance Engineering > Xantrex Technology Inc. > e-mail: jim.eich...@xantrex.com > web: www.xantrex.com > > Confidentiality Notice: This email message, including any attachments, > is for the sole use of the intended recipient(s) and may contain > confidential and privileged information. Any unauthorized review, use, > disclosure or distribution is prohibited. If you are not the intended > recipient, please contact the sender by reply e-mail and destroy all > copies of the original message. > > - > > This message is from the IEEE Product Safety Engineering Society > emc-pstc discussion list. Website: http://www.ieee-pses.org/ > > To post a messag! e to th e list, send your e-mail to emc-p...@ieee.org > > Instructions: http://listserv.ieee.org/request/user-guide.html > > List rules: http://www.ieee-pses.org/listrules.html > > For help, send mail to the list administrators: > > Scott Douglas emcp...@ptcnh.net > Mike Cantwell mcantw...@ieee.org > > For policy questions, send mail to: > > Jim Bacher: j.bac...@ieee.org > David Heald: emc-p...@daveheald.com > > All emc-pstc postings are archived and searchable on the web at: > > http://www.ieeecommunities.org/emc-pstc __ This email has been scanned by the MessageLabs Email Security System. For more information please visit http://www.messagelabs.com/email __ - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to emc-p...@ieee.org Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: emc-p...@daveheald.com All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: EMC Directive - indicating restrictions of use
In message <201048ea81ba0745aca78e4cc8839001c8b...@desmdswms201.des.grplnk.net>, dated Thu, 8 Mar 2007, "Haynes, Tim (SELEX) (UK Capability Green)" writes: >My personal view is that the warning should be on the retail packaging >so it is seen before the item is purchased. That's what 'where appropriate' means, or at least one meaning. The warning wouldn't be necessary on OEM packaging. -- OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk There are benefits from being irrational - just ask the square root of 2. John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list.Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to emc-p...@ieee.org Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald:emc-p...@daveheald.com All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc __ This email has been scanned by the MessageLabs Email Security System. For more information please visit http://www.messagelabs.com/email __
Re: EMC Directive - indicating restrictions of use
In message , dated Thu, 8 Mar 2007, john.radom...@us.schneider-electric.com writes: >I believe that this information should be included in a printed user >manual. I would also include this warning on the outside of the >enclosure, for example: on the rating label. In how many languages? It's a case where a symbol is really necessary. -- OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk There are benefits from being irrational - just ask the square root of 2. John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list.Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to emc-p...@ieee.org Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald:emc-p...@daveheald.com All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc __ This email has been scanned by the MessageLabs Email Security System. For more information please visit http://www.messagelabs.com/email __
RE: EMC Directive - indicating restrictions of use
Brian, If I was buying a product for use at home and had to wait until I had put the CD in the computer before finding out it was NOT suitable - then I would be pretty hacked off. My personal view is that the warning should be on the retail packaging so it is seen before the item is purchased. Regards Tim 6239 desk A1S77 P Please consider the environment before printing this email. _ From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of brian_mcauli...@dell.com Sent: Thursday, March 08, 2007 12:53 PM To: emc-p...@ieee.org Subject: EMC Directive - indicating restrictions of use *** WARNING *** This mail has originated outside your organization, either from an external partner or the Global Internet. Keep this in mind if you answer this message. Article 9 para 4 in EMC Directive 2004/108/EC reads as follows ….. "Apparatus for which compliance with the protection requirements is not ensured in residential areas shall be accompanied by a clear indication of this restriction of use, where appropriate also on the packaging." One way of addressing this requirement is to include information on this restriction in the instructions for use that are part of the user guide on a CD shipped with the product (in this case a PC or PC accessory). The other extreme is a large printed warning on the outside of the shipping carton indicating not suitable for use in a residential environment, together with a hard copy warning notice included in the box. 1. What's the sensible and practical middle ground ? 2. What do they really mean by the words 'clear indication' and in particular ' where appropriate' ? Rgds Brian McAuliffe - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to emc-p...@ieee.org Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: emc-p...@daveheald.com All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc __ This email has been scanned by the MessageLabs Email Security System. For more information please visit http://www.messagelabs.com/email __ This email and any attachments are confidential to the intended recipient and may also be privileged. If you are not the intended recipient please delete it from your system and notify the sender. You should not copy it or use it for any purpose nor disclose or distribute its contents to any other person. - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to emc-p...@ieee.org Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: emc-p...@daveheald.com All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: EMC Directive - indicating restrictions of use
> 1. What's the sensible and practical middle ground ? I believe that this information should be included in a printed user manual. I would also include this warning on the outside of the enclosure, for example: on the rating label. My 2 cents. John Radomski To: Sent by: cc: emc-p...@ieee.orgSubject: EMC Directive - indicating restrictions of use 03/08/2007 07:53 AM Article 9 para 4 in EMC Directive 2004/108/EC reads as follows ….. "Apparatus for which compliance with the protection requirements is not ensured in residential areas shall be accompanied by a clear indication of this restriction of use, where appropriate also on the packaging." One way of addressing this requirement is to include information on this restriction in the instructions for use that are part of the user guide on a CD shipped with the product (in this case a PC or PC accessory). The other extreme is a large printed warning on the outside of the shipping carton indicating not suitable for use in a residential environment, together with a hard copy warning notice included in the box. 1. What's the sensible and practical middle ground ? 2. What do they really mean by the words 'clear indication' and in particular ' where appropriate' ? Rgds Brian McAuliffe This email has been scanned for SPAM content and Viruses by the MessageL abs Email Security System. - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to emc-p...@ieee.org Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: emc-p...@daveheald.com All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list.Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to emc-p...@ieee.org Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald:emc-p...@daveheald.com All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc __ This email has been scanned by the MessageLabs Email Security System. For more information please visit http://www.messagelabs.com/email __
EMC Directive - indicating restrictions of use
Article 9 para 4 in EMC Directive 2004/108/EC reads as follows ….. "Apparatus for which compliance with the protection requirements is not ensured in residential areas shall be accompanied by a clear indication of this restriction of use, where appropriate also on the packaging." One way of addressing this requirement is to include information on this restriction in the instructions for use that are part of the user guide on a CD shipped with the product (in this case a PC or PC accessory). The other extreme is a large printed warning on the outside of the shipping carton indicating not suitable for use in a residential environment, together with a hard copy warning notice included in the box. 1. What's the sensible and practical middle ground ? 2. What do they really mean by the words 'clear indication' and in particular ' where appropriate' ? Rgds Brian McAuliffe __ This email has been scanned by the MessageLabs Email Security System. For more information please visit http://www.messagelabs.com/email __ - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to emc-p...@ieee.org Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: emc-p...@daveheald.com All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
