This is also common in UK where British Telecom for example, will request that your E3 interface be able to ground or float the bnc shield.
Don House wrote: > One rarely used but real application is where the DS3 coax is run between > two adjacent central offices across an alley. This was the case in Chicago > where the DS3 was a link between AT&T Long Lines and Illinois Bell. Because > of possible ground loops the coax was grounded only at one end. Normally > this would be a fiber link, but these things do happen occasionally. > > Don > > -----Original Message----- > From: Jon D. Curtis [mailto:[email protected]] > Sent: Tuesday, June 13, 2000 8:34 AM > To: [email protected] > Subject: Re: DS3 Lightning > > DS-3 is also exempt for other reasons. > > Section 4.5 specifies application of surge and overvoltage to "paired-cable > interfaces." Further the criteria of this section apply to "each > telecommunications port connecting to an outside plant pair" DS3 is not a > paired interface. > > They are discussed in section 4.6 which is entitled "Criteria for equipment > interfacing with coaxial cable ports." This section replaces section 4.5 > for > coaxial cables. It also states "these criteria are not intended for... > conventional telecommunications services, such as DS3." > > All this leaves DS3 without much of a home in section 4 of 1089. I would > assume > that the long duration of the deployment of DS3 has left the RBOCs with a > good > strategy of deployment of DS3 (adequate protection devices at the building > entry) such that they are not experiencing problems with DS3, thus no > additional > regulation is needed. Until we get additional guidance from the RBOCs or > Telcordia, it would seem the thing to do is to report when DS3 ports exist > in a > product so that future revisions of the product may be subject to > requirements > when, and if, they become necessary. > > I agree with Jim that if the DS3 stays within the building and the shield is > connected to ground at both ends that no testing would be required under 4.5 > (if > you consider that applicable at all). I do however believe that DS3 may > leave > the building and that there exist implementations which do not ground the > shield > at one end. > > -Jon Curtis > > JIM WIESE wrote: > > > If both ends are intended to be grounded and you state this it in your > > documentation, intra-building lightning is exempt on a DS-3. > > > > Jim > > > > Jim Wiese > > NEBS Project Manager/Compliance Engineer > > ADTRAN, INC. > > 901 Explorer Blvd. > > P.O. Box 140000 > > Huntsville, AL 35814-4000 > > 256-963-8431 > > 256-963-8250 fax > > [email protected] > > > > > ---------- > > > From: Joe Finlayson[SMTP:[email protected]] > > > Reply To: [email protected] > > > Sent: Monday, June 12, 2000 6:00 PM > > > To: 'NEBS Newsgroup' > > > Subject: DS3 Lightning > > > > > > > > > I am hearing mixed opinions of whether a DS3 Coax interface falls > > > under the scope of interfaces to be subjected to GR-1089 4.5.9 > > > Intrabuilding > > > Lightning Surge. The way I interpret the standard is that it does fall > > > under the scope as there is no clear definition, that I could find, for > > > "Telecommunications Port". I've seen verbiage citing examples, but no > > > clear > > > definition. This interface will not connect to outside plant and I do > > > wish > > > to claim shielded cables with grounds at both ends to avoid the testing. > > > The scope of Section 4.6 clearly eliminates DS3 as part of that section. > > > The program team is against testing it and I would not like to see a > > > prospective customer reject the report. Any and all feedback and > opinions > > > from the group (RBOC's especially) would be greatly appreciated. > > > > > > Thx, > > > > > > > > > Joe > > > > > > ********************************* > > > <<...>> > > > > > > Joe Finlayson > > > Manager, Compliance Engineering > > > Telica, Inc. > > > 734 Forest Street, Bldg. G, Suite 100 > > > Marlboro, MA 01752 > > > Tel: (508) 480-0909 x212 > > > Fax: (508) 480-0922 > > > Email: [email protected] > > > Web: www.telica.com > > > > > -- > Jon D. Curtis, P.E. > > Director of Engineering > Curtis-Straus LLC > > One Stop Laboratory for NEBS, EMC, > Product Safety, and Telecom Testing. > 527 Great Road > Littleton, MA 01460 USA > Voice 978-486-8880 Fax 978-486-8828 > email: [email protected] > WWW.CURTIS-STRAUS.COM
