Re: T3
Well, to be more clear, the difference between a "DS3" interface and a "T3" interface is simply that the T3 is intended to be used outside the building. For example, Cisco Systems here in Austin has a T3 line which connects us to the backbone provider at the telephone CO, about a mile away. Definitely an outside kind of thing. DS3, on the other hand, is "cross-connect" type connection which runs only between racks in the same building and does not require AC power fault and lightning testing. T3 is indeed a TNV interface. DS3 is SELV. Bellcore GR-1089 has tests for "broadband telecommunications interface" in section 4.6, and this would be applicable for T3. These are pretty hairy tests. There are different requirements depending on whether the equipment is intended to be used with an external protector, whether it's outdoor type equipment, etc. T3 line protection circuit will involve a transformer, a fuse and a gas-tube type surge protector. A "SidACTOR" type device has way too much capacitance to operate on a T3. The Overvoltage and lightning tests (plus all other TNV type tests) in UL 1950 are applicable if the flowchart does not get you out of it (fire enclosure, 100A^2/sec limiting, etc.). Good luck! -- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Josh Karnes Lead Safety Engineer Cisco Systems - Austin --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Re:RE: T3
forwarding for gsemin...@nuera.com Reply Separator Subject:RE: T3 Author: "Seminsky; George" List-Post: emc-pstc@listserv.ieee.org Date: 2/8/01 7:54 AM For whatever it is worth, I believe that T3 interfaces do not have to undergo NEBS GR-1089 Lightning and AC Power Fault testing whereas T1 interfaces do. The reason being that T3 interfaces are not connected to outside lines and therefore are not exposed to environmental nasties. George Seminsky Compliance Engineering Nuera Communications. Inc. 10445 Pacific Center Court San Diego, CA 92121 Ph 858 625 9220 X4410 Fx 858 625 2422 www.nuera.com -Original Message- From: David Gelfand [mailto:gelf...@memotec.com] Sent: Thursday, February 08, 2001 7:27 AM To: emc-p...@ieee.org Subject: T3 Has anyone had any experience with safety approvals to UL 1950 of T3 interfaces over coaxial cable - are power line cross tests required? Thanks in advance, David. David Gelfand Regulatory Approvals Memotec Communications Inc. Montreal Canada --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Re: T3
RE: T3The line interface unit manufacturer (TDK) also says that T3 lines remain in the building, so it would appear that it is considered SELV rather than TNV therefore no power cross. Can anyone else back this up? Thanks to all for your input! Best regards, David. - Original Message - From: Seminsky, George To: 'David Gelfand' ; emc-p...@ieee.org Sent: Thursday, February 08, 2001 10:54 AM Subject: RE: T3 For whatever it is worth, I believe that T3 interfaces do not have to undergo NEBS GR-1089 Lightning and AC Power Fault testing whereas T1 interfaces do. The reason being that T3 interfaces are not connected to outside lines and therefore are not exposed to environmental nasties. George Seminsky Compliance Engineering Nuera Communications. Inc. 10445 Pacific Center Court San Diego, CA 92121 Ph 858 625 9220 X4410 Fx 858 625 2422 www.nuera.com -Original Message- From: David Gelfand [mailto:gelf...@memotec.com] Sent: Thursday, February 08, 2001 7:27 AM To: emc-p...@ieee.org Subject: T3 Has anyone had any experience with safety approvals to UL 1950 of T3 interfaces over coaxial cable - are power line cross tests required? Thanks in advance, David. David Gelfand Regulatory Approvals Memotec Communications Inc. Montreal Canada --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
T3
Has anyone had any experience with safety approvals to UL 1950 of T3 interfaces over coaxial cable - are power line cross tests required? Thanks in advance, David. David Gelfand Regulatory Approvals Memotec Communications Inc. Montreal Canada --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org