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: randolph.j.iv...@us.ul.com David Spencer <dspencer@oresis. To: "'nebs@world.std.com'" com> <nebs@world.std.com> 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: lxwo...@msg.pacbell.com 925 823-4544 Have a Great Day! Dave Spencer Oresis Communications -----Original Message----- From: Scott Lemon [mailto:sle...@caspiannetworks.com] Sent: Wednesday, February 13, 2002 8:35 AM To: nebs@world.std.com 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: nsh...@catena.com > > -----Original Message----- > From: Scott Lemon [mailto:sle...@caspiannetworks.com] > 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 > sle...@caspiannetworks.com > www.caspiannetworks.com ********* Internet E-mail Confidentiality Disclaimer ********** This e-mail message may contain privileged or confidential information. If you are not the intended recipient, you may not disclose, use, disseminate, distribute, copy or rely upon this message or attachment in any way. If you received this e-mail message in error, please return by forwarding the message and its attachments to the sender. Underwriters Laboratories Inc. and its affiliates do not accept liability for any errors, omissions, corruption or virus in the contents of this message or any attachments that arise as a result of e-mail transmission. *****************************************************************