This question was posted on Interference Technology’s forums. The following replies are from some of our readers.
Reply #1 Reply to "what to do with spare cores?" Ground them to the chassis or system frame, both ends. Rationale: a floating core in a bundle does nothing good. Quite the contrary, it may aggravate capacitive crosstalk between different wire groups in the harness. By grounding the un-used wires both ends, you create both an electrostatic screen and a magnetic field cancelling loop, thus reducing both capacitive & magnetic Xtalk. Only caution: don't do this with equipments which are very far from each other, like in separate buildings, with maybe different ( not interconnected) earth rods or earth references. Reply #2 Michel's book, EMI Troubleshooting Techniques, is excellent and very practical. Thanks, Kate Savo Interference Technology Forums Editor www.interferencetechnology.com/ 484-688-0300 ext 26 [email protected] From: Mark Hone [mailto:[email protected]] Sent: Tuesday, March 24, 2009 10:21 AM To: [email protected] Subject: [PSES] Spare cores Gentlepeople* - Over the last forty years or so, I have seen two diametrically opposed general guides regarding what to do with spare cores in multicore cable. Sometimes the instructions are to "tie back and insulate, allowing sufficient length to allow connection if necessary", sometimes "connect all spare cores to earth". I need to have a debate with someone regarding spare cores and I'm wondering if anyone can help me any references from standards (military or commercial) that might provide definitive instruction. I have searched, but have not found anything. With thanks in anticipation, Regards, Mark * doesn't sound right, but I want to be PC -- Mark Hone, HESS Manager Wellman Defence Limited - 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]>
