Nothing I say represents the opinions or policy of my employer. I very much concur with Mr Eckert. NEBS for 'components' is seldom cost effective for anything other than very simple stuff, and may not be representative of the component's performance in the end-use installation.
My employer has had several requests for NEBS-certified power supplies, but only one customer was willing to pay the lab cost. In general, I know that that my power supplies will pass most (if not all) NEBS, if properly installed, because of the way I conduct EMC scans, safety Type Tests, and HALT. And there are several other power supply and transformer mfrs that do the same thing. Then there was the customer that mounted a power supply with two #2 screws (the mounting PEMs were for four #6 screws), then proceeded to complain that the unit could not handle shock/vibration tests. Stupidity should be very painful. luck, Brian From: emc-p...@ieee.org [mailto:emc-p...@ieee.org]On Behalf Of Ted Eckert Sent: Tuesday, August 12, 2008 9:20 AM To: emc-p...@ieee.org Subject: Re: NEBS Compliant Components There is so much involved in NEBS testing that it would be hard to qualify individual components. A hard disk or power supply might pass the temperature and vibration tests, but the final configuration will determine EMI performance. The fire testing is impossible to do on most of these components unless they are sealed in their own case. The high cost of even limited NEBS testing would discourage most component manufacturers from doing much of the work. I can't imagine somebody investing the money for the testing unless they have a likely customer lined up. Filters are one of the few exceptions. They can be tested to see if they will contain a fire within the enclosure and they don't need to do much else. (They may need to help provide part of the EMI screening, but that isn't too difficult to analyze.) Because of their simplicity, little testing is required. However, you need to find out what is covered by the "NEBS compliance" of the filter. How has the vendor tested it? Look closely at the chassis components; they need to contain a fire should it occur. That is one of the nastier tests. Choose components with a minimum of fuel for the fire. The method of assembling the components will determine a lot of the vibration and EMI performance. Ted Eckert The opinions expressed are my own and do not necessarily reflect those of my employer. --- On Mon, 8/11/08, Christine Rodham <chrisrod...@yahoo.com> wrote: From: Christine Rodham <chrisrod...@yahoo.com> Subject: NEBS Compliant Components To: emc-p...@ieee.org List-Post: emc-pstc@listserv.ieee.org List-Post: emc-pstc@listserv.ieee.org List-Post: emc-pstc@listserv.ieee.org Date: Monday, August 11, 2008, 12:07 PM Hi List Members, We are modifying an existing Networking Security product so it may reside in a NEBS environment. Does anyone know of a list of HW ( see below) that you can purchase off the shelf that is already NEBS compliant. ( Most of our HW is from off the shelf components) I know there is no guarantee the final product will meet NEBS by using NEBS components but we thought it would be a good idea to pick NEBS certified components from the start. For example we already found an air filter that is marked NEBS compliant. ( Universal Air Filter ) If anyone is interested I will compile a list of the NEBS certified components and send it out to the List Members. Mother-Boards Power Supplies HDD/RAID CPU / Memory Chassis Thank you! Christine Rodham - 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
