15.32 goes on to say that under the test conditions of (a)(1), the emissions shall not exceed the limit by more than 6db. I guess the presumption is that a typical enclosure cover will provide at least 6dB of additional attenuation.
Jim Hulbert, Team Leader Compliance Engineering & Environmental Test Systems Integration & Test / New Product Development Test Tel: 203-924-3621 (442-3621) From: [email protected] [mailto:[email protected]] On Behalf Of John Barnes Sent: Friday, June 19, 2009 9:23 AM To: John M Woodgate; ce-test, qualified testing bv - Gert Gremmen Cc: [email protected] Subject: Re: EMC Directive Applicability to Mother Boards Gert, John, The (United States) Federal Communications Commission's (FCC's) approach to approvals of separately-sold personal computer (PC) motherboards is described in Sections 15.32 and 15.102 of FCC 47 CFR Part 15, at http://www.fcc.gov/oet/info/rules/part15/PART15_07-10-08.pdf Paragraph 15.32(a)(1) says: "Section 15.32 Test procedures for CPU boards and computer power supplies. Power supplies and CPU boards used with personal computers and for which separate authorizations are required to be obtained shall be tested as follows: (a) CPU boards shall be tested as follows: (1) Testing for radiated emissions shall be performed with the CPU board installed in a typical enclosure but with the enclosure's cover removed so that the internal circuitry is exposed at the top and on at least two sides. ..." The rest of this section goes into much more detail about the testing requirements, and an alternative test configuration. Paragraph 15.102(a) says: "Section 15.102 CPU boards and power supplies used in personal computers. (a) Authorized CPU boards and power supplies that are sold as separate components shall be supplied with complete installation instructions. These instructions shall specify all of the installation procedures that must be followed to ensure compliance with the standards, including, if necessary, the type of enclosure, e.g., a metal enclosure, proper grounding techniques, the use of shielded cables, the addition of any needed components, and any necessary modifications to additional components." John Barnes KS4GL, PE, NCE, NCT, ESDC Eng, ESDC Tech, PSE, SM IEEE dBi Corporation 216 Hillsboro Ave Lexington, KY 40511-2105 (859)253-1178 phone (859)252-6128 fax [email protected] http://www.dbicorporation.com/ - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <[email protected]> All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. Website: http://www.ieee-pses.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 <[email protected]> Mike Cantwell <[email protected]> For policy questions, send mail to: Jim Bacher: <[email protected]> David Heald: <[email protected]> - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <[email protected]> All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. Website: http://www.ieee-pses.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 <[email protected]> Mike Cantwell <[email protected]> For policy questions, send mail to: Jim Bacher: <[email protected]> David Heald: <[email protected]>
