From: JIM WIESE <[email protected]> Subject: RE: Bellcore Requirement
The requirements are a little more clear in GR-63-CORE, although still not a clear as the nose on your face. You first must calculate the square footage of 1/2 of the isle in front of your system plus the area of your system including the frame it is mounted in, plus 1/2 of the square footage in the rear isle behind your system. Typical isle depths are found in GR-63-CORE. Then depending on whether your product is a system or a shelf unit, you use the appropriate tables to figure the maximum heat dissipation(based on shelf height, or frame height). Most people calculate the wattage assuming what goes in is what is dissipated (input voltage multiplied by input current). This represents worst case. However if your product outputs power to a remote device, the outside plant cable and remote device will actually be dissipating some of the heat. The cable and remote unit wattage can be subtracted from the wattage of the C.O. unit as that heat will not be dissipated in the C.O.. The reasoning behind this is the owner of the C.O. wants to be sure the HAVOC system can accommodate your system without special precautions or upgrades. They are not concerned with the heat dissipated at the remote end with respect to NEBS compliance of the C.O. unit. However if your system is being evaluated for NEBS compliance in a location other than a C.O. another method would be used for heat dissipation on a case by case basis. Jim James Wiese Regulatory Compliance Engineer ADTRAN, Inc. 205-963-8431 205-963-8250 FAX [email protected] >---------- >From: [email protected][SMTP:[email protected]] >Sent: Monday, August 11, 1997 10:55 AM >To: Treg Discussion Group >Subject: Bellcore Requirement > >What is the Bellcore requirement for something >like watts per square foot in a CO? It's based >on looking down on a rack from above so that >you get "watts per square foot". > >My memory lags on this, and I believe its >TR-499. But, I remember going through >some numberical contortions to figure >it out for a standard 17' rack. Somehow >650 watts per square foot for a standard >17' rack keeps popping into my mind. > > >
