Hi Pete:
When considering how 62368-1 is applied to an Ethernet cable, it's necessary to look at how the Ethernet cable is used. Following is how I interpret some common examples: 1) Ethernet cable used entirely with a building: No transient test 2) PoE cable that goes outside the building to a floating PoE camera: No transient test 3) Ethernet cable that connects two separate buildings: Transient test (1500 V) applies, common-mode only My reasoning is based mostly on this note from Table 13 in the 3rd Edition: Keep in mind that if the Ethernet port complies with the isolation requirement in 803.3, it will have common mode isolation that is sufficient to withstand a 1500 V transient. Most manufacturers' designs meet the 802.3 isolation requirement, but some don't. If your application involves an Ethernet cable that has different ground references at each end, the 62368-1 isolation test is 1500 V, but experience has shown this is not always sufficient. I wrote an article on this topic in 2017: https://randolph-telecom.com/wp-content/uploads/2021/03/Designing-Ethernet-C able-Ports-to-Withstand-Lightning-Surges_IN-1300.pdf Joe Randolph Telecom Design Consultant Randolph Telecom, Inc. 781-721-2848 (USA) [email protected] http://www.randolph-telecom.com -----Original Message----- From: Peter Tarver [mailto:[email protected]] Sent: Friday, July 9, 2021 1:13 PM To: [email protected] Subject: [PSES] Surges on Ethernet ports under 62368-1 Good morning. 61368-1, Table 14 (2nd ed) or Table 13 (3rd ed) discusses transients to be applied to conductors considered external circuits. Whereas in 60950-1, these tests generally applied to conductors falling under Clauses 6 or 7, the scope of the applicability of the testing appears to have expanded to include simple IEEE 802.3 circuits that exit a building structure, which were excluded from such testing under 60950-1 (where ITIC had dictated to test houses, "thou shalt not place transients on mine network circuits"). As a relative newcomer to 62368-1, I am looking for confirmation that the above is accurate. Regards, Peter Tarver <mailto:[email protected]> [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 < <mailto:[email protected]> [email protected]> All emc-pstc postings are archived and searchable on the web at: <http://www.ieee-pses.org/emc-pstc.html> http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at <http://product-compliance.oc.ieee.org/> http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: <http://www.ieee-pses.org/> http://www.ieee-pses.org/ Instructions: <http://www.ieee-pses.org/list.html> http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: <http://www.ieee-pses.org/listrules.html> http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas < <mailto:[email protected]> [email protected]> Mike Cantwell < <mailto:[email protected]> [email protected]> For policy questions, send mail to: Jim Bacher: < <mailto:[email protected]> [email protected]> David Heald: < <mailto:[email protected]> [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.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) 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]>
