Nortel Networks 411-2021-111 manual Power and Grounding Requirements, Safety requirements

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Power and Grounding Requirements

Cell sites are built to house communication equipment of the cellular telephone network. Cellular equipment can be located in stand-alone sites or in larger buildings in urban areas. Cellular equipment is traditionally powered from a +24 Vdc power plant. Some switching equipment can also be located in a cell site. It is connected with other equipment through CO cables. RF signals are transmitted using coaxial cables through areal antennas. Since cell sites are susceptible to lightning strikes, extra precautions have to take place to ensure the operation.

Safety requirements

Safety standards for installation and maintenance of electrical equipment are the object of the national codes; Canadian Electrical Code (CEC) in Canada and the National Electrical Code (NEC) in the USA. Although these codes do not govern installations of communication equipment under the exclusive control of communication utilities, it is good design and installation practice for the new equipment or system to comply with the intent of the appropriate Code. For systems installed at the customer premises outside of the above communication utilities, compliance with the Code is mandatory.

One of the basic safety rules of the national codes (CEC and NEC) in North America, for example, requires that there shall be no objectionable current on the Framework Ground conductor (grounding conductor). In practice, this usually means no measurable current.

In view of the above, communication equipment shall use a three wire distribution system as required by the codes (system with separated grounding such as Floor Ground and grounded conductor such as Battery Return or the neutral) rather than two wire power distribution system (system with joined grounding and grounded conductor).

Note: Countries outside North America may have different safety standards codes. Follow the safety standards for installation and maintenance of electrical equipment in your country accordingly.

DMS-MTX DualMode Metrocell Cell Site Description

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Contents DualMode Metrocell Page Page June Publication historyContents Cell Site Components Power and Grounding RequirementsDatafilling a Metro Cell Site AppendicesList of tables Block diagram of a 120 Stsr Metrocell using one RF FramePage Intended audience for this publication About this documentApplicability of this publication How this publication is organizedList of terms BandCarrier RF DBm CellDBW DuplexerForward path FilterIsolation LossOmni ModulationDqpsk Return lossSignal RF SectorSectorization Stsr Northern Telecoms DualMode Metrocell IntroductionDigital ready cellular product System architecture of a DualMode MetrocellMetro RF Frame Basic components of a DualMode Metrocell Universal CE Frame800 MHz cellular band Channel assignment for 800 MHz cellular systemsChannel assignment Band a 416 channels Band B 416 channels Introduction 6Introduction Standard 01.01 June Cell Site Configurations Omni configurationOverview Omni N=7 frequency reuse plan Sectorized configuration120 N=7 sectorized frequency reuse plan 60 N=4 sectorized frequency reuse plan Cell Site Layouts Omni cell site configurationRF Frame Control Channel redundancyCell Site Layouts 4Cell Site Layouts TRU/DPA Transmit cabling6Cell Site Layouts Component requirement Receive cablingNo. Frames TRUs ATCsStsr cell site configuration CE Frame RF Frame Block diagram of a 120 Stsr Metrocell using one RF FrameBlock diagram of a 120 Stsr Metrocell using three RF Frames 12Cell Site Layouts DPA 9 Port1 CCH ATC3 Port DPA 10 Port1 14Cell Site Layouts TRU/DPA ATC 16Cell Site Layouts Sector Sector Z Sector YSector Y TX/RX, 3 RX Control Channel Locate Channel Receiver Sector Stsr cell site connectionSector U Sector W22Cell Site Layouts Block diagram of a 60 Stsr Metrocell with two RF Frames 24Cell Site Layouts Block diagram of a 60 Stsr Metrocell with four RF Frames 26Cell Site Layouts Transmit cabling 28Cell Site Layouts TRU/DPA 30Cell Site Layouts Port2 ATC3 Port DPA Port1 RF Frame 32Cell Site Layouts Receive cabling 34Cell Site Layouts Sector Y 36Cell Site Layouts Component requirement 38Cell Site Layouts Standard 01.01 June Major components of a DualMode Metrocell Description Cell Site ComponentsNTAX98AA FRU Customer Service Operations 4Cell Site Components Standard 01.01 June Safety requirements Power and Grounding RequirementsPower and grounding requirements Power and Grounding Requirements 4Power and Grounding Requirements Power distribution for the CE and RF Frames in a Metrocell Frame power distributionGrounding UL/CSA approval System power protectionCEC par DC coupled signals Cable Identification 10Power and Grounding Requirements Standard 01.01 June Datafill Overview Datafilling a Metro Cell SiteTable Acualm Table ClliAlarm Points Metro RF Frame ATCCavities Fan Pwr Hsmo +27V a Rip Connector J206 Table VCHINV, CCHINV, LcrinvPort # Example of Metro TRU datafill Frequency Assignment ExampleIcrm Example of Metro ICRM/TRU hardwire configuration8Datafilling a Metro Cell Site Standard 01.01 June Appendix a DualMode Metrocell Cell Site Specifications System ConfigurationRadio Frequency Audio Interface AlarmsDC Power Requirements Power Distribution RequirementsMechanical Environmental PackagingRegulatory Electromagnetic Emissions Radiated EmissionsTelecom Compliance Product Safety =7 Frequency plan Band a Appendix B Frequency Plans=7 Frequency plan Band B =4 Frequency plan Band B =4 Frequency plan Band a10Frequency Plans Standard 01.01 June Page Cell Site Description