Thanks to all for some great input on this subject! -- Regards, Scott
Joe Finlayson wrote: > Be careful when choosing your "Seismic Rated Rack". I had the > misfortune of purchasing such a rack for a test and had the thing come apart > at the seams. My product held up great, but watching this thing increase in > displacement as we got further into the testing was a scary sight. I > eventually changed to another vendor as recommended by my lab and > experienced a world of difference. I sent photos of the results to the > vendor and they refunded my money, but that's a small portion of the costs > incurred. > > Thx, > > Joe > > -----Original Message----- > From: [email protected] [mailto:[email protected]] > Sent: Wednesday, February 13, 2002 1:32 PM > To: [email protected] > Subject: RE: GR-63 Seismic > > I agree with Dave. The test of a shelf level unit is only intended to be > representative of a typical installation. Unless you can test the actual > configuration of the entire rack there are too many variables, the rack > itself being only one of them. The weights used (flat plate, round,etc.), > the weight distribution (top to bottom, side to side and back to front) and > the weight mounting (stiff multipoint mounting of weight plates will > stiffen the whole rack while center point mounting of gym weights on a > shelf could add to the movement) all contribute a lot to the test > variations and rack movement during the test. Add to this the fact that the > weight distribution and the weight itself is unlikely to match the final > installation and you can see why the specific rack used is not so critical > as long as it is designed to withstand seismic forces itself (a "seismic > rated rack"). > > Here at UL we test shelf units in a seismic rated rack, weigh it down as > Dave describes and specify the test configuration in our NEBS reports. We > have never had a problem with the tests/test reports being accepted by the > RBOC community. > > Randy Ivans > Global Program Manager -Telecommunications > Underwriters Laboratories Inc. > 1285 Walt Whitman Rd. > Melville, NY 11747 > TEL: 631-271-6200; Ext. 22269 > Department FAX: 631-439-6096 > Direct FAX: 631-439-6131 > email: [email protected] > > > > David Spencer > > <dspencer@oresis. To: "'[email protected]'" > > com> <[email protected]> > > Sent by: cc: > > nebs-approval@wor Subject: RE: GR-63 Seismic > > ld.std.com > > > > > > 02/13/02 12:38 PM > > Please respond to > > nebs > > > > > > Hi Scott, > It is not necessary to quantify the use data for self-level equipment. The > racks on hand in CO's are purchased because they meet the requirements of > that installation and the test data for those racks is reviewed just as > rigorously as the data on the equipment that goes into them. Your mandate > is to ensure that the tests your unit are subjected meet the test criteria. > > For your self-level unit, the intent of the test is to assertion the > operational performance under seismic stress in the worst possible > 'typical' > installation. Consequently, your unit should be placed at the top of an > unequal-flange seismic rack where the deflection is greatest. The rack, > per > GR63 section 5.4.1.3, should be fully loaded with dummy weights to ensure > it > duplicates the mass and stiffness of a fully loaded rack. Additional > weights are place on top of the rack to simulate cable weight. > > The test plan should be approved by an RBOC SME, such as Larry Wong or one > of his designates at SBC, prior to running the test. CA has the biggest > threat and they know what "representative" means to them. The test report > will show that the unit has been tested with an approved zone 4 rack and > load configuration. > > If your test lab doesn't have test plans approved prior to testing, get > another lab. The going rate for repeating a seismic test is too high to > have to do it twice because someone didn't have a plan approved. > > The contact information I have for Larry Wong is a little dated, e.g. no > guarantees: > [email protected] > 925 823-4544 > > Have a Great Day! > Dave Spencer > Oresis Communications > > -----Original Message----- > From: Scott Lemon [mailto:[email protected]] > Sent: Wednesday, February 13, 2002 8:35 AM > To: [email protected] > Subject: Re: GR-63 Seismic > > This has been my experience too in talking with test labs. Maybe this is > the generally accepted way?.?.? Are you guys addressing this in any way in > your user/customer docs (e.g. only tested for compliance in Hendry, model > xyz, etc.)?? > > Naftali Shani wrote: > > > Sounds like the CE + CE = CE? > > > > In my limited experience with the 1 product tested so far NOT in its > > normally installed rack, the lab did just that (generic Hendry). > > > > Regards, > > Naftali Shani, Catena Networks (www.catena.com) > > 307 Legget Drive, Kanata, Ontario, Canada K2K 3C8 > > 613.599.6430/866.2CATENA (X.8277); C 295.7042; F 599.0445 > > E-mail: [email protected] > > > > -----Original Message----- > > From: Scott Lemon [mailto:[email protected]] > > Sent: Wednesday, February 13, 2002 10:19 AM > > To: Nebs (E-mail) > > Subject: GR-63 Seismic > > > > Greetings Nebs group, > > > > I am interested in the general consensus with respect to one aspect of > > seismic testing of rack mounted equipment.... > > > > If a shelf-based system, which is designed to be installed in any > > seismic approved rack assembly (e.g. 19"), is seismic tested in a > > particular rack (e.g. Newton), is the performance normally extrapolated > > to be representative of installation in any generally "seismic approved" > > 19" rack (e.g. Hendry, tested by rack manuf with dummy loads, etc.)?? > > In other words, is GR-63 seismic compliance for the shelf system linked > > only to the rack in which it was tested, or will any generally tested > > GR-63 "seismic approved" rack suffice? > > > > Any and all opinions welcome. > > > > Thanks, > > Scott > > > > -- > > Regards, > > > > Scott Lemon > > CASPIAN NETWORKS > > [email protected] > > www.caspiannetworks.com > > ********* Internet E-mail Confidentiality Disclaimer ********** > > This e-mail message may contain privileged or confidential > information. 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