Joe,
Thanks for the heads up on the higher power draft. Even though the summary of requirements indicate 15.4W, the math does not add up. 48V at 350mA provides a possible load of 16.8W. I have a PoE injector that is rated 48V, .420mA, again more than 15.4W. 60950 does not require a fire enclosure when LPS is specified with certain other conditions. 60065 does not require a fire enclosure when the source is less than 15W. Is 15.4W for PoE coincidence or aligned with 60065 fire enclosure requirements? Any thoughts on this? Best regards, Don Don Umbdenstock Manager Compliance Engineering Tyco Safety Products / Sensormatic 6600 Congress Avenue Boca Raton, FL 33487 USA Phone: 561.912.6440 [email protected] <mailto:[email protected]> ________________________________ From: Joe Randolph [mailto:[email protected]] Sent: Thursday, April 02, 2009 10:54 PM To: Umbdenstock, Don; [email protected] Subject: RE: PoE injector maximum power On 4/2/2009, Don Umbdenstock wrote: I am curious about the 15.4W PSE requirement. I have an idea; does anyone know the committee's rationale? Hi Don: I always assumed that the committee was simply worried about overheating the wires in the cable, and this was the limit they decided to use, based on some analysis. Maybe it's more complicated than that, but clearly they had to set some sort of limit. BTW, there is a committee working on a higher power version of POE that, as I recall, doubles the available power by using additional conductors in the cable. I have seen a draft of the standard, but I can't recall the details. Joe Randolph Telecom Design Consultant Randolph Telecom, Inc. 781-721-2848 (USA) [email protected] http://www.randolph-telecom.com <http://www.randolph-telecom.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]>
