Beware that not all ILECs will accept the waiver if the intrabuilding surge requirement if you use shielded cable. Per GR1089 the shielded cbale is exempt only if the sguield is grounded at both ends. Unfortunately, some do not allow grounding the shield at both ends, thus you can't apply the waiver.
Check Verizon's point of view at http://www.verizonnebs.com/technical.html Neven > > Jeffrey, > > In a previous life with a large multi-national manufacturer of base stations and > base station controllers, I went through the same issue. Using the grounded > cable shield (at both cable ends) to waiver the Intra-building surge > requirement. The product requirement was changed to meet intrabuilding for > ethernet, RS232 and then full 2nd level surge & AC power cross on T1. > Performing Intra-building surge on Ethernet, T1 and RS232 ports is problematic > and sometimes catastrophic. The cable shield made no difference to the test > results. > Applying the surge direct to the conductors as detailed in GR1089 with the surge > applied to a single conductor in turn and the remaining 3 conductors grounded > (for a 4 wire i/f) is severe and protection needs to be designed in at pcb level > to protect the port. > T1 ports are usually transformer coupled and the transformers are normally rated > for 1500V common mode protection. Differential surges will probably be the > issue. > The same applies to ethernet ports. Protection can be designed at pcb level to > protect the port and care must taken to select protection that does not load the > lines with too much capacitance or the port will not function. The ethernet port > is very sensitive to capacitive loading. > RS232 ports are not transformer coupled and fast TVS diode arrays can be used to > meet Intra-building surge. > Intra-building surge can be met for these type of ports, 2nd level surges & AC > power cross is also possible but careful designed in protection to match the > interface circuitry is reqd. > > Andy > > _____________________________ > Andy White > EMC Engineer > Nokia Mobile Phones > San Diego, CA > Tel 858 831 4534 > [email protected] > _____________________________ > > > -----Original Message----- > From: ext Collins, Jeffrey [mailto:[email protected]] > Sent: Friday, June 13, 2003 5:08 AM > To: [email protected] > Subject: GR1089 4.5.9 Intrabuilding Lightning Strike Telecom Ports > > > > All, > > We have taken the waiver to this requirement by using shielded cables that were > grounded on both ends. Since it is common for carriers to float > one end of their grounds we are planning to perform this test on our telecom > ports. Looking at the levels of the surge in table 4-4, I'm not confident that a > grounded shielded telcom cable would make the difference in passing this test. ( > Surges are at 800V and 1500V) > ( Ports / Cables are T1, E1, Ethernet, and RS232) > > My plan is to run this test with both unshielded ungrounded cables and shielded > grounded cables. > > Does anyone have any experience in passing this test where the shielded/grounded > cable made the difference? > Anyone have a theoretical opinion/prediction on this? > > Thanks in advance, > > Jeffrey Collins > Sr. HW Engineering Manager > EMC/ NEBS/ Reliability/ Safety > CIENA Corporation > 5965 Silver Creek Valley Rd. > San Jose, CA. 95138 > (408) 571-3002, Fax (408) 965-2705 > [email protected] > http://www.ciena.com > > > ------------------------------------------- > 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: > [email protected] > with the single line: > unsubscribe emc-pstc > > For help, send mail to the list administrators: > Ron Pickard: [email protected] > Dave Heald: [email protected] > > For policy questions, send mail to: > Richard Nute: [email protected] > Jim Bacher: [email protected] > > Archive is being moved, we will announce when it is back on-line. > All emc-pstc postings are archived and searchable on the web at: > http://www.ieeecommunities.org/emc-pstc > > > ------------------------------------------- > 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: > [email protected] > with the single line: > unsubscribe emc-pstc > > For help, send mail to the list administrators: > Ron Pickard: [email protected] > Dave Heald: [email protected] > > For policy questions, send mail to: > Richard Nute: [email protected] > Jim Bacher: [email protected] > > Archive is being moved, we will announce when it is back on-line. > All emc-pstc postings are archived and searchable on the web at: > http://www.ieeecommunities.org/emc-pstc 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: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: [email protected] Dave Heald: [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
