On 25 Mar 2009 at 21:47, [email protected] wrote: > > Does it matter for the discussion that: > > 1) Power is not present at the output of the source unless > the other side of the cable connects to a PD (powered > device) which "signals" to the sourcing equipment it is a PD > and to turn it on. If you unplug the PD, the power goes off.
The requirements apply for all load modes of operation, including when the handshaking is completed and the PoE output supplies power to the PD. > 2) The power supply in the sourcing equipment are isolated > per IEEE 802.3 (1500Vrms). What if the power supply is Class 2 Equipment? Then the isolation requirements are somewhat larger than 1500 V. Also, doesn't the supplied power to the PD have to continue to be isolated from earth, as do the ethernet circuits? Peter Tarver [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]>
