Thanks Marko,
I think you are answering my questions. It is tricky to word these things sometimes. So it sounds like 4 wires (2 feeds) come to the cabinet and go to their respective feeds. And those same four wires will go to one DC source, so they are tied together, except for AT&T. I think we are finding that the test setup does not necessarily yeild the same results. We tested with Cabinet having the feeds jumpered and then go through one set of LISNs and to one DC source and are getting different results from having emissions measured on FEED A and a different DC source going to FEED B (we are load sharing). I am very curious then what most people do and how they test. We are finding if you do not test with Jumpers at the PDU and instead try and simulate "most" CO wiring schemes then the results are different and failing for us. We are about to test further scenarios, and so will have a better idea of what is going on. Maybe it is just our system. Wouldn't doubt it! thanks again, dereck -----Original Message----- From: Marko Radojicic [mailto:marko.radoji...@mapleoptical.com] Sent: Tuesday, September 24, 2002 3:05 PM To: 'Plante, Dereck Raymond (Dereck)'; emc-p...@majordomo.ieee.org Subject: RE: Central Office Wiring - Conducted Emissions Dereck, I'm not sure that I totally understand your question. CO powering is provided from a redundant A/B set of leads. In *most* COs, there is a single battery plant from which both sets of cables are breakered. There is then either a direct connection to your equipment or it goes through various distribution frames or panels prior to your equipment. In AT&T labs, they do things a little different. They actually have separate A and B battery rooms and run the cables from there. This improves their network reliability. In the end, for your piece of equipment, there is no difference. You can connect the A (or B) feeds through LISNs and measure the CE profile. Attaching LISNs to all four leads simultaneously is should have the same result. Cheers, Marko -----Original Message----- From: Plante, Dereck Raymond (Dereck) [mailto:drpla...@lucent.com] Sent: Tuesday, September 24, 2002 10:23 AM To: emc-p...@majordomo.ieee.org Subject: Central Office Wiring - Conducted Emissions Does a CO wire up to a redundant cabinet with 2 wires, so jumpered at the cabinet, or 4 wires (any theory on percentages)??? And if it is 4 wires, do the two Feeds go to two completely seperate sources, or are they jumpered sources (so in parallel)? How do people typically test there cabinet for Conducted Emissions??? We were testing with the cabinet jumpered and going throught the LISNs to one Source. We had a passing system with mods, and so we tried to only connect the LISN to one feed and power the other feed with a seperate DC source, then we got failing results with or without mods. Interesting..... We are thinking we are getting some crazy current loops. Does anyone have an opinion as to their best recommended test setup for conducted emissions that will best represent the true wiring in a central office? We are thinking, but have not yet tried, to test 4 wires coming out of the cabinet, going through 4 different LISNs and then going to one DC power source. Any comments??? Dereck R. Plante Compliance Engineer Lucent Technologies Switching Solutions Group, OPENet Solutions 255 Independence Drive Hyannis, MA 02601-1854 (508) 862-3302 ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on "browse" and then "emc-pstc mailing list" ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on "browse" and then "emc-pstc mailing list"
