IEEE 802-3at PoE Plus Operating Efficiency - Valer

IEEE802.3atPoEPlusOperatingEfficiency:HowtoKeepaHotApplicationRunningCoolValerieMaguireTheSiemonCompanyWhatisPowerOverEthernet(PoE)?•Runningpowerconcurrenttodataoverstructuredtelecommunicationscabling•PowercanbeinjectedbytheEthernetswitch(end-span),or•Powercanbeinjectedbyadeviceinsertedintothetelecommunicationschannel(mid-span)AdvantagesofPoE•Simplifiedinfrastructuremanagement•Loweredpowerconsumption•ReducedoperationalcostsforapplicationsuchasVoIP•Improvedsafetyduetoseparationfromthebuilding’smainACpowerringMarketTrendsAccordingtothemarketresearchfirmVDC:Source:VentureDevelopmentCorporation•Initiallypublishedas,“IEEEStd802.3af-2003”•Contentincorporatedinto,“IEEE802.3-2005”•Operatesoncategory3andhigherratedtwisted-paircablingThePublishedPoEStandardPoETerminologyandCapabilities•PowerSourcingEquipment(PSE):–adevice(end-spanormid-span)thatprovidespowerinaPoEsetup–Maximumallowedcontinuousoutputpoweris15.40W•PoweredDevice(PD):•adevicepoweredbyaPSE•maximumpowerusageis12.95WPoEApplications–Type1•IPbasedvoiceandvideotransmissionequipment•IP-basednetworksecuritycameras•Wirelessaccesspoints(WAPs)•RadiofrequencyIDtagreaders•BASsystems(thermostats,smokedetectors,alarmsystems,securityaccess,industrialclocks/timekeepers,andbadgereaders)•Printservers•BarcodescannersHigherPoweredApplications–BeyondPoE•Laptopcomputers•Thinclients(typicallyrunningwebbrowsersorremotedesktopsoftwareapplications)•SecuritycameraswithPan/Tilt/Zoomcapabilities•InternetProtocolTelevision(IPTV)•Biometricsensors•WiMAXtransceiversprovidingwirelessdataoverlongdistances(e.g.point-to-pointlinksandmobilecellularaccess),and•Highvolumesofotherdevicesthatrequireadditionalpower•UnderdevelopmentbyIEEE802.3atTaskForce•WilloperateinconjunctionwithPoE•End-spanandmid-spandeviceswillbesupported•PerIEEE,“TheenhancedstandardwillprovidethemaximumpowertothePDasallowedwithinpracticallimits”•Target:mid-2009IntroducingPoEPlus–Type2PowerDeliveryComparisonPoE(Type1)PoEPlus(Type2)MinimumPoweratPSEOutput15.4W30.0WMaximumPowerAvailabletoPD12.95W29.95WOutputVoltageandOperatingCurrentComparisonPoE(Type1)PoEPlus(Type2)AllowedPSEOutputVoltage44–57VDC50–57VDCNominalPSEOutputVoltage48VDC53VDCMaximumDCCableCurrent350mA(perpair)600mA(perpair)PoEPlusCompatibilitywithEthernetApplications•PoEPlusapplicationistargetedtobecompatiblewith10BASE-T,100BASE-T,and1000BASE-T•Compatibilitywith10GBASE-TisnotedasnotbeingprecludedbythenewStandard•Approachensuresoperationoverthelargestpercentageoftheinstalledcablingbasepossible•AppliedcurrentsassociatedwithPoEPluscausetemperaturerisewithinthecabling•Specifiedoperatingrange:20ºC–60ºC•Elevatedtemperaturesresultin:–Increasedinsertionloss–Riskofprematureagingofjacketingmaterials•ElevatedtemperaturesDONOTresultin:–Cablesmelting–SafetyrisksHeatRiseConsiderationsImpactonMinimumCategoryofCablingPoE(Type1)PoEPlus(Type2)TIA:MinimumCategoryofCablingCategory3Category5*ISO:MinimumCategoryofCablingClassCClassD**withDCloopresistance25ΩConstructingtheBundleTestConfigurationPlacingThermo-couplers100-CableBundleCross-SectionFinalMeasurementConfigurationTIAUTPTemperatureRiseProfilesCalculatedTemperatureProfiles•Themaximumcurrentperpairforagivenambienttemperature(t)canbeapproximatedbyusingthefollowingformula:where:AtIt5.0601−⋅=ρ5eUTP6UTP6AUTPρ1.471.611.73CalculatedMaximumCurrentvs.Temperature5eUTP6UTP6AUTP60º0mA0mA0mA55º424mA465mA499mA50º600mA657mA706mA45º735mA805mA865mAFora100-cablebundle:ComparativeOperatingEnvironmentsPoE(Type1)PoEPlus(Type2)MaximumOperatingTemperature60º50ºInstallationConstraintsNoneMaximum5kWpowerpercablebundleProvidingPoEPlusInstallationGuidance•ProposedTIATSB-184,GuidelinesforSupportingPowerDeliveryoverBalanceTwisted-PairCabling”–Transmissionparameters–Installationconditions–Applicationsconsiderations–Fieldtestingforspecificimplementationssuchasmid-span–SafetyissuesareNOTaddressed•Seealso,proposedISO/IECTR29125,“CablingGuidelinesforRemotePoweringofDTE’s”PoEPlus-ReadyCablingConsiderations•Ensureoperatingtemperaturesdonotexceed50ºC•Specifycablingtypesandinstallationpractices,suchasbundling,thatsupportminimaltemperatureriseduetoappliedcurrent•Thereisnomethodtocooldownhotpathways•ThereisnomethodformonitoringPoEPlusinducedtemperatureriseintheinstalledcablingChallengingEnvironmentsforPoEPlus•Excessivebundling•Hightemperaturepathways•CablingwithimprovedheatdissipationcharacteristicscanprovidereliefintheseenvironmentsMeasuredTemperatureRiseforallMediaMeasuredTemperatureRiseforallMediaThe“BakedPotato”Myth•Myth:Screened/shieldedsystemstrapheatgeneratedbyPoEandPoEPlusapplicationsor“aluminumtrapsheatsin–that’swhyyoucookbakedpotatoesinit”•Fear:Coolingandsafetyisaconcernforscreened/shieldedsystemssupportingPoEandPoEPlusapplications•Facts:–Metalisabetterdissipaterofheatthanplasticcompounds–PerTIAcontributions,screened/shieldedsystemshavesignificantlybetterheatdissipationthatUTPsystems–Cablesareconditionedattemperaturesmuchhigherthan60ºCandthereisnoconcernofshortingordegradationoftheinsulationatthesetemperaturesTemperatureDe-ratingofUTPvs.ScreenedCables•Ins